Managing Amino Acid Content

amino acids and more.Information for the Feed Industry Volume 07/Number 01 • April 2006

Amino acids in animal nutrition:Should the incorporation rates of freeamino acids in poultry and swine diets be limited?

Feed formulation

Editorial

Dear reader,

In this edition, we take an in-depth look atvarious nutritional and technical issues. Webegin by reviewing the efficiency of supple-mental amino acids in animal nutrition.Some nutritionists seem to have some un-certainty about the potential of a threshold inclusion level that should not be exceededwhen using crystalline amino acids. The dataprovided in this article should dispel any misconceptions and give you the perfect basisfor the use of supplemental amino acids inyour feed formulations.

Our second article focuses on raw materialvariability and how to deal with it. As youwill read, the proper management of varia-bility, including but not limited to the estab-lishment of suitable control programs, willlead to a lot of economical advantages for you.

Finally, our third contribution introducesisoleucine, an essential amino acid, which is receiving more and more attention fromswine nutritionists. In collaboration with our guest author, Dr. Brian Kerr from the US De-partment of Agriculture, Dr. Meike Rade-macher reviews the needs for isoleucine in practical diet formulation for growing-finishing pigs.

Enjoy reading!

Dr. Alfred Petri

Research Highlights

Amino acids in animal nutrition:Should the incorporationrates of free amino acids in poultry and swine diets be limited? 1-12

How to Manage the Variability of Protein andAmino Acid Contents in Raw Materials 13-22

Isoleucine in Pig Nutrition 23-32

Effect of DL-Methionine on VariousPerformance and Slaughter Characteristics in Slowly GrowingBroilers Fed According to OrganicFarming Recommendations . . . . . . 33

Dietary Trypotphan Need of BroilerMales from Forty-Two to Fifty-Six Days of Age . . . . . . . . . . . . . . . . . . . . 34

Effect of Glutamine and Spray-DriedPlasma on Growth Performance,Small Intestinal Morphology, and Immune Responses of Escherichia coli K 88+-challenged weaned pigs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Key information

• Limiting crystalline amino acid supplemen-tation in commercial practice can limit theflexibility and accuracy of least cost feed for-mulation and thus needs a critical review.

Degussa Feed Additives

• It is scientifically proven that crystallineamino acids are 100 % digestible for swineand poultry.

• In pigs, metabolic availability of amino acidscan be impaired by once-a-day feeding and by amino acid imbalance. However,

Volume 07/ Number 01 • April 2006 amino acids and more.

2 Degussa Feed Additives

these impairments are easily overcome byproviding at least two meals per day and byapplying the ideal protein concept.

• In turkeys, low protein diets combined withhigh levels of supplemental amino acidswork well when combined with the idealprotein concept.

• In broilers, additional research is needed tofully understand the metabolic effects oflow protein diets.

• Using advanced diet formulation systems,such as net energy, ideal protein, and di-gestible amino acids, leads to more accurateand flexible diets, including reduction of dietary CP content without impairment ofanimal performance.

Introduction

Today, more than ever, crystalline aminoacids are being used in diets for pigs andpoultry to replace a portion of the essen-tial amino acids provided by protein-richraw materials. The driving forces are en-hanced herd management, growing en-vironmental concerns, and the need formore flexibility in raw material selection.However, undoubtedly the single mostimportant driving force is our improvedunderstanding of the animal’s exact di-etary amino acid needs for protein depo-sition. By closer meeting these needs,protein accretion is maximized and fatdeposition is minimized resulting in abetter quality product.

Currently, DL-Methionine, L-Lysine, L-Threonine, and L-Tryptophan are com-mercially available for feed production,and in the future, other amino acids,such as isoleucine or glycine might be-come available. Supplemental aminoacids allow nutritionists more flexibilityin raw material selection when formulat-ing diets, while also allow the nutrition-ist to more accurately meet the animal’sdietary needs as they change due to im-proved genetic potential.

Despite the aforementioned benefits offormulating diets using crystalline aminoacids, supplementation rates in commer-cial practice are sometimes still limited.One of the reasons for this limitation are

older practical recommendations sug-gesting that free lysine in the diet shouldnot exceed 0.15 to 0.30 %, becausehigher incorporation would lead to im-pairment of performance. Another po-tential reason is the concern that com-mercially produced amino acids are lessthan 100 % digestible and available forutilization. A third reason might be theadverse effects that low CP, crystallineamino acids supplemented diets have onthe growth and carcass performance ofpigs and poultry. Finally, a fourth reasonfor this limitation has been economicand supply constraints of the commer-cially available amino acids.

The purpose of this paper is to addressthese concerns by first reviewing theavailable literature regarding digestibilityand bioavailability of crystalline aminoacids. Next, we will address the effects offeeding frequency and amino acid imbal-ance or antagonism on crystalline aminoacid utilization. Finally, the concept oflimiting the use of crystalline aminoacids in practice will be discussed includ-ing a comprehensive review of the ef-fects of low crude protein diets on pig,broiler, and turkey performance.

Digestibility and availability of crystallineamino acids

Most often when we discuss digestibilityand availability, we are making some ref-erence to the quality of a raw material,such as cottonseed, meat, or soybeanmeals. The digestibility and availability ofthe various raw materials is extremelyimportant when diets are formulated ona digestible basis. This is demonstrated inTable 1 from Batterham (1992), as theileal digestible amino acids from dietsformulated on cottonseed, meat, or soy-bean meals were retained in the bodyprotein of growing pigs at much lowerlevels than 100 %. While these digestibleamino acids were considered to be 100 % digestible, it is obvious that theywere not all either available or utilizedby the pig. Many factors can influencethe bioavailability of amino acids in rawmaterials, including processing condi-

Degussa Feed Additives

Volume 07/ Number 01 • April 2006amino acids and more.

tions, presence of anti-nutritional factorsor fibers, or physical and chemical com-position of the protein (Batterham, 1992;Parsons, 2002).

Conversely, we seldom think of crys-talline amino acids being any less than100 % digestible and available to the animal. Butts et al. (1993) compared theileal amino acid flow in pigs fed either aprotein free (PF) or a purified diet whereall amino acids were provided in crys-talline form. They reported that all of theamino acids recovered from pigs fed thePF diet were of endogenous origin, andthat there was no difference in theamino acid flow between the syntheticand PF diets. These data indicate that allsynthetic amino acids were effectivelyabsorbed by the pig. This suggestion issupported by the recent work of Lemmeet al. (2005). Ross 308 broilers were fedeither a PF or a purified diet with allamino acids provided in crystalline form.The apparent ileal digestibility of thecrystalline amino acids was determinedand then standardized by correcting forbasal endogenous losses. As shown inFigure 1, there were no differences be-tween the PF and purified diets, whichagain indicates clearly that crystallineamino acids are 100 % ileal digestible ingrowing broilers.

These research reports are supported bythe review of Lewis and Bailey (1995),who reported that out of seven total cit-ed reports, six demonstrated that crys-talline amino acids were fully absorbedin both pigs and poultry. Furthermore,Sauvant et al. (2002) from the FrenchINRA have suggested that crystallineamino acids should have digestibility co-efficients of 100 % for both pigs andpoultry.

The effects of feeding frequency and amino acid imbalances on the utilization of crystalline amino acids

Crystalline amino acids are 100 % di-gestible and available. However, thisdoes not mean that they will be 100 %utilized by the animal in every situation.

3

Table 1: Retention of ileal digestible amino acids in protein (%) by grow-ing pigs fed diets based on cottonseed meal, meat meal or soy-bean meal (Batterham, 1992)

In fact, the efficiency of utilization is af-fected by the number of meals that a pigor chicken receives per day. Batterhamand Morrison (1981) reported that pigperformance was negatively affected pigswere fed diets with crystalline Lys at lowfeeding frequencies (i. e. one meal perday). However, Cook et al. (1983) report-ed that increasing feeding frequencyfrom one to three meals per day was suf-ficient to avoid negative effects on freeAA utilization. These findings are sup-ported in a review by Batterham (1984),who determined that efficiency of theutilization of crystalline Lys improveswhen pigs are fed from once up to six

Figure 1: Ileal amino acid digestibility of an amino acid mixture consistingof crystalline amino acids fed to growing broilers from 17 to 22days of age. The digestibilities were corrected for basal ilealamino acid losses measured with either a protein free diet (light)or enzymatically hydrolyzed casein diet (dark; Lemme et al.,2005).

Raw MaterialRetention(% dig. AA retained in protein) Cottonseed Meat Soybean SEM

Meal Meal Meal

Lysine 0.36 0.60 0.75 0.012

Threonine 0.44 0.59 0.40 0.017

Methionine 0.38 0.45 0.45 0.013

Tryptophan 0.46 0.45 0.38 0.010

* standardised by PfD * standardised by EHC120

100

80

60

40

20

0

Lys

Met

Met+

CysThr

Trp Arg Ile Leu Val

Stan

dar

dis

edile

ald

iges

tib

ility

,%

100.

310

1.4

99.6

99.0

98.7

98.9

97.0

99.2

101.

610

1.0

100.

599

.7

99.9

103.

4

100.

399

.7

99.9

101.

4



times per day, which is close to ad libitumconditions. These findings have been re-cently supported by le Bellego et al.(2001), who indicated that energy andprotein retention were not affected bythe CP content or by the feeding fre-quency when pigs were fed two differentdiets of 17.4 % and 13.9 % CP (i. e. highfree AA inclusion level) and offered feedat two or seven meals per day (Table 2).The decrease in efficiency of utilizationof crystalline amino acids when fed onlyonce per day is likely due to their rapidabsorption once digested compared withthe amino acids from intact proteinsources. Yen et al. (2004) demonstratedthis as crystalline Lys and Thr were ab-sorbed quicker than protein bound Lysand Thr. The result of such rapid absorp-tion could be a temporary amino acidimbalance or antagonism resulting in in-creased oxidation rates of these essentialamino acids, and ultimately decreasedefficiency of utilization.

Amino acids can also have adverse ef-fects on growth, which are widely recog-nized as dietary imbalances or antago-nisms. An imbalance is defined as achange to the pattern of dietary aminoacids that results in decreased feed intakeand growth, while an antagonism is anegative interaction between structurallysimilar amino acids (D’Mello, 2003). Animbalance is most often caused in prac-tice by either a small addition of an es-sential amino acid to a low CP diet or anincomplete mixture of amino acidsadded to a diet. An example of thiswould be when a growing pig diet calls

for 0.15 % L-Lysine · HCl, 0.08 % L-Threonine, and 0.04 % L-Tryptophan,but the addition of L-Tryptophan is over-looked when the feed is being mixed. Anantagonism, on the other hand, such asthe Arg:Lys or branch-chain amino acidantagonisms, can occur regardless of an-other amino acid being more limiting.For example, a typical broiler diet is sup-plemented with 0.25 % DL-Met and0.10 % L-Lysine·HCl to meet the mi-nimum Met and Lys needs, but if the Arglevel also is not taken into account, theArg:Lys ratio is decreased resulting in im-paired performance despite having ade-quate levels of the first two limitingamino acids. Both imbalances and an-tagonisms also decrease the efficacy ofutilization of amino acids; however, bothof these adverse effects can be easilyavoided by ensuring that diets are for-mulated according to the ideal proteinconcept, which ensures that dietary es-sential amino acids are maintained in theproper ratios to each other (Baker, 1994;NRC, 1994; NRC, 1998; Mack et al.,1999; Rademacher et al., 2001; Lemme,2003). This concept has been shown tobe effective by Nonn and Jeroch (2000)who reduced the CP levels of growing-finishing pigs diet (down to 10.7 %crude protein in finisher diet) leading tothe incorporation of eight crystalline AA.There were no differences in the controlor low CP groups in ADG (869 g/d vs.863 g/d) and lean meat deposition (55.2vs. 55.0 %), respectively.

In summary, crystalline amino acids are100 % digestible and available to bothpigs and poultry. Furthermore, assumingthat these animals are fed at or near adlibitum levels and that their diets are for-mulated and mixed in accordance withthe ideal protein concept, there is no rea-son that the use of crystalline aminoacids will result in imbalances or antago-nisms.

Table 2: Effect of meal frequency on energy utilization of a 13.9 % lowprotein diet in growing pigs (65 kg BW. MJ/day/kg BW0.60;Le Bellego et al. 2001)

Meals / day 2 7 RSD1 Effect1

ME intake 2.51 2.50 0.07 ns

Heat production 1.34 1.35 0.03 ns

Retained energy 1.17 1.16 0.07 ns

As protein 0.33 0.34 0.02 ns

As fat 0.84 0.82 0.07 ns

1 Statistical significance: analysis of variance with meal frequency as the main effect. Statistical significance:

ns: p>0.05; RSD: Residual Standard Deviation.


5Degussa Feed Additives

The effects of supplemental crystallineamino acids in low CP diets

Reducing the CP by supplementing dietswith crystalline amino acids has provento be very effective in the swine industry.Great progress has been made in theswine industry with the understandingand subsequent utilization of net energy,standardized ileal digestible amino acidsand the ideal protein concept. The imple-mentation and the use of these tech-niques increase the flexibility in raw ma-terial selection during diet formulation,and perhaps most important, they arecost effective. Today, not only cangrowth performance and meat quality bemaintained or even improved, but nitro-gen excretion into the swine waste alsois decreased as the amount of costly indi-gestible and unbalanced protein is re-duced.

A review of the effects of reducing CPand supplementing swine diets withcrystalline amino acids is shown in Table3. This review encompasses a variety ofweight ranges, sexes, and dietary CP lev-els. The first part of this review reportsthe growth and carcass performance ofpigs fed low CP diets, while the secondpart focuses on the effects of low CP diets on nitrogen balance. The growthperformance results are very consistentas they indicate that there is practicallyno difference in ADG or feed:gain whenpigs are fed low CP diets relative to thosefed typical high CP diets. The carcass per-formance results also are impressive in-dicating very small differences in loinmuscle area or backfat. It should be not-ed the diets in a majority of the datasetslisted were formulated either on di-gestible amino acids, ideal protein, or netenergy, but rarely all three. This is im-portant because some of the effects inthe carcass performance are likely due toeither incomplete ideal protein ratios re-sulting in a deficiency in one or more es-sential amino acids or excess energy, ifformulated on digestible or metaboliz-able energy, that will be stored as fat if not needed for protein synthesis. Re-gardless, the nitrogen balance data alsoare extremely consistent as 100 % re-ported a decrease in fecal and urinary

nitrogen, and 57 % report improved nitrogen retention compared to the pigsfed high CP diets. Overall, these resultssuggest that low CP diets with variouslevels of crystalline amino acids can beused just as effectively for maintaininggrowth and carcass performance whileimproving nitrogen balance in pigs com-pared to the typical commercial dietswith higher levels of CP.

As positive as the data are for swine, thesame cannot be said in poultry. Despitemajor advances over the last ten years inbroiler nutrition, there is still a consider-able amount of research needed to vali-date the use of low CP diets for poultry,particularly broilers. As shown in Table4, the effects of low CP diets for broilersare much more variable than those forpigs. However, the effects of the low CPdiets relative to broilers fed more tradi-tional high CP diets are still relativelysmall with the differences in ADG rang-ing from -8.3 to less than -0.5 g. Manyattempts to significantly reduce the CPcontent of broiler diets have failed fortwo main reasons: 1. the “protein” requirement of poultry

seems to be higher than it is in swineand

2. the ratios among essential amino acids(ideal protein concept) were notmaintained. Two different researchgroups have recently reported positiveresults when feeding low CP diets tobroilers. Aletor et al. (2000) reducedthe dietary CP content from 22.5 % to17.1 %, which led to the incorpora-tion of supplemental Met, Lys, Thr,and Trp. They reported that growthperformance was not different be-tween these two CP groups, but thatfurther CP reduction failed to main-tain performance. These data are sup-ported by the work of Dean (2005),who reported that broilers fed low CPdiets (16.21 %) with supplemental es-sential AA + Gly grew 0.62 g more perday as well as improving theirfeed:gain by 7 points relative to thosefed a traditional high CP diet. Grantedthat these latest results are only twodata points in the grand scheme, theyshow promise that low CP diets canand will work in broilers.



Table 3: Effects of reducing crude protein and supplementing crystalline amino acids in swine diets

Weight, kg Sex Dietary CP Total Crystalline AA Low CP Animal Performancelevels (%) Lys added to Low CP (Relative to high CP)

level diet

High Low % ADG, kg FCR LMA, cm2 Backfat, cm Reference

9 to 93 Mixed 19.0/ 15.0/ 1.04/ Lys,Thr,Trp +0.01 +0.07 +0.50 +0.19 Kerr et al., 1995(3 phases) 16.0/ 12.0/ 0.82/

14.0 11.0 0.67

10 to 20 Mixed 21.8 12.0 1.10 Lys,Thr,Trp, Met, -0.06 +0.27 Brudevold and Glu, His, Ile,Val Southern, 1994

10 to 20 Mixed 19.4 12.0 1.10 Lys,Thr,Trp, Met, +0.01 0 Brudevold and Glu, His, Ile,Val Southern, 1994

20 to 46 Gilts 16.0 14.0 0.82 Lys,Thr,Trp, Met +0.08 +0.05 -0.61 +0.14 Figueroa et al., 2002

12.0 Lys,Thr,Trp, Met +0.05 -0.03 -0.66 +0.33

20 to 55 Gilts 16.0/ 14.0/ 0.83/ Lys,Thr,Trp -0.01 +0.08 +0.05 Tuitoek et al.,(2 phases) 14.0 12.0 0.67 1997

12.0/ Lys,Thr,Trp, Ile, -0.03 +0.16 +0.2110.0 Val

22 to 37 Barrows 16.0 12.0 0.87 Lys,Thr,Trp -0.02 +0.06 Kerr et al., 2003a

25 to 110 Gilts 21.2/ 17.6/ 1.15/ Lys,Thr,Trp -0.02 +0.10 -1.82 -0.03 Kerr et al., 2003b17.5/ 14.3/ 0.93/15.6/ 12.8/ 0.78/13.5 10.9 0.64

27 to 100 Barrows 20.1/ 15.6/ 1.02/ Lys,Thr,Trp, Met, -0.04 -0.08 -0.13 Le Bellego et al.,(2 phases) 17.5 13.3 0.84 Ile, Val 20021

28 to 47 Mixed 16.0 12.0 0.84 Lys,Thr,Trp -0.01 +0.08 Kerr et al., 2003b

31 to 82 Barrows 15.2 11.1 0.87 Lys,Thr,Trp, Met -0.09 +0.12 Gomez et al., 2002a2

33 to 57 Barrows 15.9 11.7 0.83 Lys,Thr,Trp, Met -0.07 +0.20 Gomez et al., 2002a2

35 to 113 Mixed 17.0/ 13.0/ 0.95/ Lys,Thr,Trp, Met, -0.04 +0.08 -2.1 +0.31 Shriver et al.,(3 phases) 15.0/ 11.0/ 0.80/ Ile, Val 2003

13.0 9.0 0.65

70 to 110 Gilts 15.5 11.8 0.80 Lys,Thr,Trp 0 +0.08 -1.8 +0.10 Knowles et al., 19981

74 to 102 Gilts 15.2 12.7 0.75 Lys,Thr,Trp, Met -0.01 0 -1.0 +0.05 Knowles et al., 1998

74 to 117 Barrows 12.6 9.2 0.64 Lys,Thr,Trp, Met, -0.06 0 -2.8 +0.23 Knowles et al., 1998Ile, Val

Nitrogen balance data Fecal N, Urinary Retained N,g/d N, g/d %

22 Barrows 16.0 12.0 0.80 Lys,Thr,Trp -0.35 -2.25 +2.13 Kerr and Easter, 1995

16.0 12.0 0.81 Lys,Thr,Trp -0.26 -3.82 +6.96

36 Barrows 18.0 14.0 0.96 Lys,Thr,Trp, Met, -0.70 -8.50 +7.90 Shriver et al., 2003Ile, Val

41 Gilts 18.0 14.0 0.97 Lys,Thr,Trp, Met -1.08 -2.58 +1.09 Figueroa et al., 2002

65 Barrows 18.9 16.7 0.91 Lys,Thr,Trp, Met -0.03 -5.20 -2.00 Le Bellego et al.,14.6 Lys,Thr,Trp, Met, -0.04 -11.50 -2.90 20011

Ile, Val

17.4 13.9 0.87 Lys,Thr,Trp, Met, -1.60 -11.20 -1.20Ile, Val

1Diets were formulated to maintain a Lys:NE ratio.

2Diets were formulated to maintain the Illinois Ideal protein ratios (Baker, 1994).



Table 4: Effects of reducing crude protein and supplementing crystalline amino acids in broiler and turkey diets

Age Sex Dietary CP Total Crystalline AA Low CP animal performanceSpecies level, % Lys added to Low CP (Relative to high CP)

level diet

Broilers High Low % ADG, g FCR Breast, Misc. Reference%

1 to 17 d Female 22.2 16.21 1.12 Met, Lys,Thr, Arg, Val, -0.57 -0.17 Dean, 20051

Ross Ile, Phe, His,Trp, Leu, Gly

16.21 Met, Lys,Thr, Arg, +0.62 -0.07(+Gly+ Val, Ile, Phe, His,Trp,Ser = Leu, Gly, Ser2.32 %)

28 to 52 d Male 19.0/ 15.0/ 1.05/ Met, Lys, Glu -8.3 +0.21 -0.62 Fat pad, % Kerr and Kidd, 1999a1

(2 phases) Ross 18.0 14.0 0.95 + 0.15

15.0/ Met, Lys, Glu, Arg, -3.9 +0.04 -0.11 +0.1114.0 Thr,Trp, Ile,Val

28 to 45 d Male 19.4 18.2 1.04 Met, Lys,Thr -1.0 0 +0.01 Fat pad, % Kerr and Kidd, 1999b1

Ross -0.04

16.7 Met, Lys,Thr, Ile,Trp, Val -1.4 +0.04 +0.20 +0.12

1 to 42 d Male 22.0/ 20.0/ 1.27/ Met, Lys,Thr,Trp -2.3 -0.02 N-exc., % Ferguson et al.,(2 phases) Cobb x 20.6 18.2 1.12 -17.6 1998a2

Aviagen

1 to 43 d Male 26.4/ 24.1/ 1.54/ Met, Lys,Thr,Trp -0.3 +0.1 N-exc., % Ferguson et al.,(2 phases) Cobb x 21.5 19.6 1.15 -17.0 1998a2

Aviagen 21.9/ 16.5 Met, Lys,Thr,Trp -2.6 +0.2 -20.3

Turkeys BW, kg FCR Breast, Misc.%

1 to 4 wks Male 28.4 24.8 1.66 Met, Lys, Val +0.03 -0.06 Waibel et al., 2000b3

B.U.T. 6 20.9 Met, Lys,Thr, Val, Ile, Arg,Trp +0.02 -0.11

18.2 Met, Lys,Thr,Val, Ile, Arg,Trp -0.01 -0.06

8 to 12 wks Male 23.4 19.5 1.32 Met, Lys, Val +0.01 +0.02 Waibel et al., 2000b3

B.U.T 6 16.3 Met, Lys,Thr,Val, Ile, Arg,Trp -0.07 +0.04

14.2 Met, Lys,Thr,Val, Ile, Arg,Trp -0.25 +0.07

16 to 20 wks Male 16.8 14.4 0.87 Met, Lys,Thr -0.18 +0.01 Waibel et al., 2000b3

B.U.T 6 12.0 Met, Lys,Thr, Val, Ile, Arg,Trp -0.43 +0.15

10.4 Met, Lys,Thr, Val, Ile, Arg,Trp -0.36 +0.16

0 to 18 wks Male 29.0/26.9/ 26.7/23.8/ 1.74 Met, Lys,Thr +0.03 -0.04 +0.15 Kidd et al., 1997Nicholas 22.7/19.6/ 20.9/18.0/

16.8/14.2 15.4/13.1

24.4/22.6/ Met, Lys,Thr -0.42 -0.06 -0.3019.1/16.5/14.1/11.9

3 to 20 wks Male 26.5/24.0/ 23.9/21.6/ 1.60/1.45/ Met, Lys,Thr,Trp, Val, Arg, -0.21 -0.02 -0.58 Lemme et al., 2004(5 phases) B.U.T 6 21.0/18.0/ 18.9/16.2/ 1.25/1.10/ Leu, Ile, His, Phe

16.0 14.4 0.95

6 to 20 wks Male 23.1/20.7/ 21.2/19.0/ 1.47/1.28/ Met, Lys,Thr -0.06 -0.025 -0.82 Waibel et al., 2000a(4 phases) B.U.T 6 18.0/15.7 16.5/14.5 1.07/0.89

6 to 21 wks Male 25.3/22.2/ 23.7/20.7/ 1.58/1.32/ Met, Lys,Thr -0.35 -0.025 -0.93 Waibel et al., 2000a(5 phases) B.U.T 6 20.0/17.8/ 18.7/16.6/ 1.15/0.96/

16.0 14.9 0.821 Diets were formulated to maintain the Illinois Ideal protein ratios (Emmert and Baker, 1997).2 Diets were formulated to meet digestible AA recommendations of NRC (1994).3 Low and high crude protein diets were formulated to maintain constant Lys:ME ratio.



The effects of low CP diets for turkeys re-ported in Table 4 are much more consis-tent than that reported for broilers. Infact, the turkey data is more similar tothat of the pigs than it is of the broilers.This may make more sense than it seemsat first, because production turkeys areslower growing than commercial broil-ers. Additionally, turkeys and pigs aresimilar in physiological age, i. e. both areapproaching puberty and the plateau oftheir growth curves when they reachtheir respective processing ages. Compar-atively, commercial broilers are 7 to 8weeks old (or younger) when processed;yet they will not reach puberty for an-other 10 to 13 weeks. So in turkeys, justas in pigs, growth performance was basi-cally identical when they were fed eitherlow CP or traditional high CP diets.

Should crystalline amino acid supplemen-tation rates be limited in practice?

Despite all of the success and promisethat research on low CP, crystallineamino acid supplemented diets hasshown, it is sometimes still a commonpractice to put minimum constraints forcrude protein and/or limit the inclusionof crystalline amino acids. This is particu-larly true for Lys, as older recommenda-tions suggested that crystalline Lys

Table 5: Diet and calculated composition of growing pig diets containinggraded levels of L-Lysine·HCl (De la Llata et al. 2002)

should not exceed 0.15 to 0.30 % (“5pounds per ton”) of a pig or poultry diet.The result of this suggestion is that thediets were limited regarding how low inCP that they could go. These recommen-dations were likely made due to lack ofother amino acids, namely threonineand tryptophan, being commerciallyavailable. However, that is not the casetoday. The commercial availability ofthese amino acids increases the flexibilityof the diet formulation, as well as im-proving the overall protein quality of adiet.

A research group at Kansas State Univer-sity investigated the concept of limitingcrystalline amino acid usage in growing-finishing diets for pigs. In their first seriesof experiments, they tested the effects ofsupplemental L-Lysine · HCl in diets for-mulated on metabolizable energy and to-tal amino acid levels (de la Llata et al,2002). Seven diets containing gradedlevels of L-Lysine · HCl (0 to 0.30 %) inreplacement of soybean meal were for-mulated for growing pigs from 30 to 45kg (Table 5). These diets were isocaloric,they contained the same level of totalLys provided either by soybean meal orL-Lysine · HCl, and the nutrient levels ofThr, Trp, and Met were allowed to float.

The performance data from the growingperiod are presented in Figure 2; ADG,ADFI and feed efficiency were similar inthe 0, 0.05, 0.10, and 0.15 % L-Lysine ·HCl treatments, but performance de-clined when levels exceeded 0.15 %.These authors also reported similar results for the finishing period (45 to 70kg). It becomes clear that another aminoacid besides Lys is limiting growth per-formance when supplemental Lys ex-ceeds 0.15 % of diet. Therefore, theseauthors concluded that unless othercrystalline amino acids could be added tothe diet to overcome this deficiency, thenL-Lysine · HCl supplementation shouldbe limited to 0.15 % or less in diets forgrowing-finishing pigs.

In their second series of experiments,they tested the effects of supplemental L-Lysine · HCl (0 to 0.40 %) in nursery di-ets (Tokach et al., 2003). However, in

L-Lysine-HCl %

Ingredient, % 0 0.05 0.10 0.15 0.20 0.25 0.30

Corn 54.84 56.22 57.61 59.00 60.49 61.85 63.24

Soybean meal 46.5 % 36.31 34.88 33.44 32.00 30.46 29.02 27.59

Fat 6.00 6.00 6.00 6.00 6.00 6.00 6.00

L-Lysine-HCl - 0.05 0.10 0.15 0.20 0.25 0.30

Minerals, vitamins, etc. 2.85 2.85 2.85 2.85 2.85 2.88 2.87

Calculated composition

Lysine, % 1.25 1.25 1.25 1.25 1.25 1.25 1.25

Methionine:Lysine 27 26 26 25 25 24 23

Met+Cys:Lysine 57 55 54 53 52 51 49

Threonine:Lysine 66 65 63 61 59 57 56

Tryptophan:Lysine 21 21 20 19 19 18 17

Protein, % 21.5 21.0 20.4 19.9 19.3 18.8 18.1

ME, kcal/kg 3578 3578 3578 3578 3578 3578 3578



these experiments, the diets were formu-lated to contain 1.36 % true ileal di-gestible Lys and L-Thr and DL-Met wereallowed to come into the diet as neededto maintain the true ileal digestible idealThr and Met+Cys ratios to Lys. The dietswere again isocaloric, but this time theywere formulated on a net energy basis.Pigs were fed from 10 to 20 kg BW on anad libitum basis.

The growth performance results from thesecond series of experiments are shownin Figure 3. Regardless of L-Lysine · HCllevel fed, there was no difference ingrowth performance across all treat-ments. The authors concluded that Lyscould be supplemented as high as 0.40 % of the diet provided that othersupplemental amino acids were avail-able. These results are strikingly differentfrom those reported in the first series ofexperiments as maintaining the idealprotein ratios for Thr and Met to Lys andformulating on a true ileal digestible basis allowed pigs to perform much bet-ter than when the diets were formulatedon total amino acids and Thr and Metwere allowed to float.

These two datasets from Kansas StateUniversity typify the past, present, andfuture of crystalline amino acid usage.First, de la Llata et al. (2002) suggestedlimiting supplemental Lys to 0.15 % ofthe diet, because performance was im-paired at levels above that. However, theperformance was not truly limited by Lysbut rather another amino acid, likelyThr, became more limiting than Lys dueto the decreasing levels of soybean mealas Lys level in the diet increased. Thisdataset is an accurate depiction of thepast mindset regarding crystalline aminoacid usage, because during the 1980’sand 90’s there was considerable priceand more importantly supply constraintson supplemental Thr and Trp. As such,most nutritionists did not want to risknot having the needed Thr or Trp, and sothey simply restricted the amount ofsupplemental Lys in the diet, which inturn limited the usage of the other sup-plemental amino acids.

Figure 2: Feed conversion and average daily gain of growing pigs fed dietscontaining graded levels of L-Lysine HCl (de la Llata et al. 2002).

Table 6: Diet and calculated composition of nursery pig diets containinggraded levels of L-Lysine-HCl (Tokach et al. 2003)

L-Lysine-HCl %

Ingredient, % 0 0.10 0.20 0.30 0.40

Corn 48.99 52.12 55.25 58.39 61.52

Soybean meal, 46.5 % CP 46.41 43.29 40.17 37.05 33.93

Fat 1.00 0.81 0.63 0.44 0.25

L-Threonine 0.02 0.07 0.11 0.16 0.20

L-Lysine-HCl 0.00 0.10 0.20 0.30 0.40

DL-Methionine 0.08 0.11 0.14 0.17 0.20

Minerals, vitamins, etc. 3.50 3.50 3.50 3.50 3.50

Calculated Analysis

Total Lysine, % 1.53 1.52 1.51 1.51 1.50

True ileal digestible,%

Lysine 1.36 1.36 1.36 1.36 1.36

Methionine:Lysine 32.1 33.3 34.4 35.5 36.7

Met+Cys:Lysine 60.0 60.0 60.0 60.1 60.1

Threonine:Lysine 64.9 65.0 65.2 65.3 65.4

Tryptophan:Lysine 21.8 20.5 19.3 18.1 16.9

NE, kcal/kg 3227 3227 3227 3227 3227

1.881.861.841.821.801.781.761.741.721.70

0.00 0.05 0.10 0.15 0.20 0.25 0.30

820

810

800

790

780

770

760

% crystalline lysine

ADG, gF/G

Feed

-to

-gai

n-r

atio

dai

lyw

eig

ht

gai

n



Next, Tokach et al. (2003) gave a glimpseof what might be possible with crys-talline amino acid usage. They reportedthat supplemental Lys could easily go ashigh as 0.40 % of the diet (the highestlevel that they tested) without impairinggrowth performance providing that sup-plemental Thr and Met were provided inthe diet. Of course, the obvious improve-ment from the previous to the currentdataset is that the authors have account-ed for the next limiting amino acids intheir diets. By doing so, they have en-sured the proper ratios of amino acidswill be provided to the pigs, which is theexact purpose of the ideal protein con-cept. They were able to do this becausethe first four limiting amino acids arecommercially available as economicallyviable options. The second point to thecurrent dataset is that Tokach et al.(2003) formulated their diets to meet thetrue ileal digestible amino acid needscompared with formulating on a totalbasis in the previous datasets. Formulat-ing diets on an ileal digestible, apparent,true, or standardized basis is an improve-ment from a total basis because ileal di-gestibility accounts for the amino acidsfrom a raw material or crystalline aminoacid, which are not available to the ani-mal. A review of these concepts has beenwritten previously by Rademacher et al.(2001). Lastly, the diets by Tokach et al.

(2003) were formulated on a net energyas opposed to a metabolizable energy basis as used by de la Llata et al. (2002).The net energy system most accuratelymeets the energy demands of an animal.It limits excess energy in the diets by fur-ther categorizing raw materials by theirquality as an energy source, that is fatsand carbohydrates make much better en-ergy sources than do intact proteins andamino acids. The benefits of the net energy system in swine have been recentlyreviewed by Rademacher (2005). Theend result of the use of these systems,ideal protein, true ileal digestible aminoacids, and net energy, is that the animalis provided with its nutritional require-ments as close as possible resulting in themost efficient growth with maximumprotein and minimal fat deposition.

While quite a few nutritionists still set alimit on the amount of L-Lysine·HCl intheir diets, there seems to be no logicaljustification for doing so especially whennutritional improvement strategies, suchas digestible amino acids, the ideal pro-tein concept, and the net energy system,are used. Although, currently, the con-tribution of synthetic lysine to meetingthe broiler’s needs is lower than inswine, there is no doubt that similar im-provements in poultry nutrition will beavailable on the practical level soon.

Figure 2: Feed conversion and average daily gain of growing pigs fed dietscontaining graded levels of L-Lysine HCl (de la Llata et al. 2002).

1.50

0.050

% crystalline lysine

ADG, g F/G

Feed

-to

-gai

n-r

atio

1.491.481.471.461.451.441.431.421.411.40

0.1 0.15 0.2 0.25 0.3 0.35 0.4

600

595

590

585

580

575

570

565

560

dai

lyw

eig

ht

gai

n



References

Aletor, V. A., I. I . Hamid, and E. Pfeffer (2000): Low protein amino

acid-supplemented diets in broiler chickens: Effects on performance,

carcass characteristics, whole-body composition and efficiencies of

nutrient utilization. J. Sci. Food and Agric. 80: 547-554.

Baker, D. H. (1994): Ideal protein for pigs. Minnesota Nutrition Con-

ference. Pg. 235. University of Minnesota Extension Service, St. Paul,

MN.

Balnave, D. and J. Bake (2002): Re-evaluation of the classical dietary

arginine-lysine interaction for modern poultry diets: A review.

World's Poult. Sci. 58: 275.

Batterham, E. S. (1984): Utilization of free lysine in pigs. Pigs News

Info 5:85.

Batterham, E. S. (1992): Availability and utilization of amino acids

for growing pigs. Nutr. Res. Rev. 5: 1-18.

Batterham, E. S. and R. D. Morrisson (1981): Utilization of free

lysine by growing pigs. Br. J. Nutr. 46: 87-92.

Brudevold, A. B., and L. L. Southern (1994): Low-protein, crystalline

amino acid-supplemented, sorghum-soybean meal diets for the 10- to

20-kilogram pig. J. Anim. Sci. 72:638-647.

Butts, C. A., P. J. Moughan, W. C. Smith, and D. H. Carr (1993): En-

dogenous lysine and other amino acid flows at the terminal ileum of

the growing pig (20 kg body weight): The effect of protein-free, syn-

thetic amino acid, peptide and protein alimentation. J. Sci. Food and

Agric. 61: 31-40.

Canh, T. T., A. J. A. Aarnink, J. B., Schutte, A. Sutton, D. J. Lang-

hout and M. W. A. Verstegen, (1998): Dietary protein affects nitrogen

excretion and ammonia emission from slurry of growing-finishing

pigs. Livestock Production Science 56: 181-191.

Cook, H., G. R. Frank, D. W. Giesting, and R. A. Easter (1983): The

influence of meal frequency and lysine supplementation of a low pro-

tein diet on nitrogen retention of growing pigs. J. of Anim. Sci.

57(Suppl. 1): 240–241 (Abstr.).

D’Mello, J. P. F. (2003): Adverse Effects of Amino Acids. In: Amino

acids in animal nutrition. Ed. J. P. F. D’Mello CAB International,

Wallingford, UK.

Dean, D. (2005): Amino acid requirements and low crude protein,

amino acid supplemented diets for swine and poultry. Ph. D. Disser-

tation, Louisiana State University, Baton Rouge.

De la Llata, M., S. S. Dritz, M. D. Tokach, R. D. Goodband, and J. L.

Nelsen (2002): Effects of increasing L-Lysine HCl in corn- or

sorghum-soybean meal-based diets on growth performance and car-

cass characteristics of growing-finishing pigs. J. Anim. Sci. 80:2420-

2432.

Emmert, J. L., and D. H. Baker (1997): Use of the ideal protein con-

cept for precision formulation of amino acid levels in broiler diets. J.

Appl. Poult. Res. 6: 462-470.

Ferguson, N. S., R. S. Gates, J. L. Taraba, A. H. Cantor, A. J. Pesca-

tore, M. L. Straw, M. J. Ford, and D. J. Burnham (1998a): The effect

of dietary protein and phosphorus on ammonia concentration and

litter composition in broilers. Poult. Sci. 77:1085-1093.

Ferguson, N. S., R. S. Gates, J. L. Taraba, A. H. Cantor, A. J. Pesca-

tore, M. L. Straw, M. J. Ford, and D. J. Burnham (1998b): The effect

of dietary crude protein on growth, ammonia concentration and litter

composition in broilers. Poult. Sci. 77:1481-1487.

Figueroa, J. L., A. J. Lewis, P. S. Miller, R. L. Fischer, R. S. Gomez,

and R. M. Diedrichsen (2002): Nitrogen metabolism and growth per-

formance of gilts fed standard corn-soybean meal diets or low-crude

protein, amino acid-supplemented diets. J. Anim. Sci. 80:2911-2919.

Gomez, R. S., A. J. Lewis, P. S. Miller, and H. Y. Chen (2002a):

Growth performance, diet apparent digestibility, and plasma metabo-

lite concentrations of barrows fed corn-soybean meal diets or low-pro-

tein, amino acid-supplemented diets at difference feeding levels.

J. Anim. Sci. 80: 644-653.

Kerr, B. J., and R. A. Easter (1995): Effect of feeding reduced protein,

amino-acid supplemented diets on nitrogen and energy balance in

grower pigs. J. Anim. Sci. 73: 3000-3008.

Kerr, B. J., and M. T. Kidd (1999a): Amino acid supplementation of

low-protein broiler diets: 1. Glutamic acid and indispensable amino

acid supplementation. J. App. Poult. Res. 8: 298-309.

Kerr, B. J., and M. T. Kidd (1999b): Amino acid supplementation of

low-protein broiler diets: 2. Formulation on an ideal amino acid ba-

sis. J. App. Poult. Res. 8: 310-320.

Kerr, B. J., F. K. McKeith, and R. A. Easter (1995): Effect on perfor-

mance and carcass characteristics of nursery to finisher pigs fed re-

duced crude protein, amino acid-supplemented diets. J. Anim. Sci. 73:

433-440.

Kerr, B. J., J. T. Yen, J. A. Nienaner, and R. A. Easter (2003a): In-

fluences of dietary protein level, amino acid supplementation and en-

vironmental temperature on performance, body composition, organ

weights, and total heat production of growing pigs. J. Anim. Sci. 81:

1998-2007.

Kerr, B. J., L. L. Southern, T. D. Bidner, K. G. Friesen, and R. A.

Easter (2003b): Influence of dietary protein level, amino acid supple-

mentation and dietary energy levels on growing-finishing pig perfor-

mance and carcass composition. J. Anim. Sci. 81: 3075-3087.

Kidd, M. T., B. J. Kerr, J. A. England, and P. W. Waldroup (1997):

Performance and carcass composition of large white toms as affected

by dietary crude protein and threonine supplements. Poult. Sci.

76:1392-1397.



Knowles, T. A., L. L. Southern, T. D. Bidner, B. J. Kerr, and K. G.

Friesen (1998): Effect of dietary fiber or fat in low-crude protein,

crystalline amino acid-supplemented diets for finishing pigs. J. Anim.

Sci. 76: 2818-2832.

Le Bellego, L., J. van Milgen, S. Dubois, and J. Noblet (2001): Ener-

gy utilization of low-protein diets in growing pigs. J. Anim. Sci. 79:

1259-1271.

Le Bellego, L., J. van Milgen, and J. Noblet (2002): Effect of high

temperature and low-protein diets on the performance of growing-

finishing pigs. J. Anim. Sci. 80: 691-701.

Lemme, A. (2003): The Ideal Protein Concept in broiler nutrition. 2.

Experimental data on varying dietary ideal protein levels.

AminoNews 4 vol. 2: 7-14.

Lemme, A., H. S. Rostagno, A. Petri, and L. F. Albino. (2005): Stan-

dardized ileal digestibility of crystalline amino acids. Proceedings of

the 15th European Symposium on Poultry Nutrition, Balatonfuered,

Hungary.

Lewis, A. J. and J. S. Bayley (1995): Amino acid bioavailability. In:

Bioavailability of nutrients for animals, edited by C. B. Ammer-

mann, D. H. Baker, and A. J. Lewis Academic Press, San Diego,

USA: 35-65.

Li, D. F., W. T. Guan, H. M. Yu, J. H. Kim and I. K. Han (1998): Ef-

fects of amino acids supplementation on growth performance for

weanling, growing and finishing pigs. As. J. of Anim. Sci. 11: 21-29.

Mack, S., D. Bercovici, G. de Groote, B. Leclerc, M. Lippens, M. Pack,

J. B. Schutte, and S. van Cauwenberghe, (1999): Ideal amino acid

profile and dietary lysine specification for broiler chickens of 20 to 40

days of age. Br. Poult. Sci. 40: 257-265.

Maenz, D. D. and C. M. Engele-Schaan (1996): Methionine and 2-

hydroxy-4-methylthiobutanoic acid are partially converted to non-

absorbed compounds during passage through the small intestine and

heat exposure does not affect small intestinal absorption of methion-

ine sources in broiler chicks. J. Nutr.126: 1438-1444.

Nonn, H. and H. Jeroch (2000): Investigation on N-reduced feeding

and use of free amino acids in fattening pigs. Archiv für Tierzucht 43:

179-192.

NRC (1994): Nutrient requirement of poultry - 9th revised edition.

National Academy Press, Washington D. C., USA.

Parsons, C. M. (2002): Digestibility and availability of protein and

amino acids. In Poultry Feedstuffs: Supply Composition and Nutritive

Value. Eds. J. M. McNab, and K. N. Boorman, CAB International,

Wallingford, UK.

Rademacher, M., (2005): Net energy system for pigs – application for

reduced protein, amino-acid supplemented diets and its impact on pig

performance and diet formulation. AminoNews 6(2):1-6.

Rademacher, M., W. C. Sauer, and A. J. M. Jansman, (2001): Stan-

dardized ileal digestibility of amino acids in pigs. The new system.

Degussa AG, Feed Additives Division, Hanau, Germany.

Sauvant, D., J. M. Perez, and G. Tran (2002): Tables de composition

et de valeur nutritive des matières premières destinées aux animaux

d’élevage, Eds INRA. France.

Shriver, J. A., S. D. Carter, A. L. Sutton, B. T. Richert, B. W. Senne,

and L. A. Pettey (2003): Effects of adding fiber sources to reduced

crude-protein, amino acid-supplemented diets on nitrogen excretion,

growth performance, and carcass traits of finishing pigs. J. Anim. Sci.

81: 492-502.

Tokach M. D., M. U. Steudinger, S. S. Dritz, J. M. DeRouchey, R. D.

Goodband, J. L. Nelssen, and J. L. Usry (2003): Effect of increasing

crystalline amino acids and the subsequent change in diet net energy

on growing performance. Swine Day 2003. Kansas State University:

47-55.

Tuitoek, K., L. G. Young, C. F. M. de Lange, and B. J. Kerr (1997):

The effect of reducing excess dietary amino acids on growing-finishing

pig performance: An evaluation of the ideal protein concept. J. Anim.

Sci. 75: 1575-1583.

Waibel, P. E., C. W. Carlson, J. A. Brannon, and S. L. Noll (2000a):

Limiting amino acids after methionine and lysine with growing

turkeys fed low protein diets. Poult. Sci. 79: 1290-1298.

Waibel, P. E., C. W. Carlson, J. A. Brannon, and S. L. Noll. (2000b):

Identification of limiting amino acids in methionine- and lysine-sup-

plemented low-protein diets for turkeys. Poult. Sci. 79: 1299-1305.

Yen, J. T., B. J. Kerr, R. A. Easter and A. M. Parkhurst (2004): Dif-

ference in rates of net portal absorption between crystalline and pro-

tein-bound lysine and threonine in growing pigs fed once daily. J. of

Anim. Sci. 82: 1079-1090.

Dr. Robert L. Payneemail: [email protected]

Dr. Vincent Hessemail: [email protected]



How to Manage the Variability of Protein and AminoAcid Contents in Raw Materials

Raw Materials

501020

Key information

• Variability of raw material quality is un-avoidable. In order to minimize its effect, it isnecessary to define which raw materialsshould be sampled, what the appropriatesampling frequency is, and which analyticalprocedures should be used.

• A good quality control program is advanta-geous as early as the reception of the rawmaterials, and it can lead to lot refusals,price renegotiation with the suppliers, linearprogramming matrix updates, or separatestorage solutions.

• There are also long-term advantages result-ing from proper management of variability,i.e. assessment of raw materials and suppli-

ers according to variability or adequate safe-ty margins in the formulation.

• Formulation management, including moni-toring the amino acid content via NIR, allowscost-effective and nutritionally adequatefeed production, and it is crucial to main-taining good animal performance.

• For cost-effective feed formulation prac-tices, stochastic formulation also is a possi-ble alternative to traditional linear program-ming.

CP

%

Region 1 (CP = 14.5 %)

UWL

MV

Number of samples

16.0

15.0

14.0

13.0

12.0

11.0

10.0

9.0

8.0

7.0

6.0

Region 1(CP = 15.1 %)

Region 2(CP = 15.0 %)

Region 3(CP = 14.2 %)

UAL

LWL

LAL

Region 3 (CPCP = 7.6 %)

1 8 15 23 30 37 44 51 59 66 73

Figure 1: Crude protein (CP) content of wheat samples (Spanish harvest 2003-2004). UWL and LWL = upper and lowermargins for 95 % population; MV = mean value

UAL, LAL = Upper and lower tolerance limits

UWL, LWL = Upper and lower alarm limits



Introduction

The nutrient content of raw materialsused in feed production can be highlyvariable due to genetics, climate, soilcharacteristics; fertilisers applied duringthe development of the vegetable ingre-dients, processing, transport and storageconditions. This variability also affectsthe protein content and therefore theamino acids which represent one of themost important nutrients. As an exam-ple, Figure 1 illustrates the large variabil-ity in the protein content (CP) of wheatharvested in Spain between 2003 and2004 which ranged from below 8 % toabove 16 % CP in the 73 samples ana-lyzed in the respective time period. Suchvariability in the nutrient content of araw material will heavily affect accuracyof feed composition if it is not consideredproperly.

Therefore, in this paper, we will addressthe importance of a quality control pro-gram to manage the variability of proteinand amino acid contents in raw materials.

Effect of raw material quality on feed formulation accuracy and precision

The production of a quality and consis-tent feed in terms of nutrient content re-quires the implementation of raw mater-ial quality control programs. If the nutri-ent content of a raw material is not wellknown and/or is highly variable, the actual nutrient content of the feed will dif-fer from that specified in the formulationprogram and from what is stated on thebag tag. That is, the feed will not have

accuracy. This is true for any nutrient,including protein and amino acids.

There will be always some variability inthe raw material composition from onelot to another, regardless of the qualitycontrol program used, as so this variabili-ty is transferred to the feed and thereforecan differ from one batch to another.That is, the feed is lacking precision.

These concepts of accuracy and precisionare graphically visualized in the Figure 2.Each point in the figure represents thecomposition of a batch and the targetrepresents the feed composition desired.

The A scenario is ideal, where all thebatches have similar composition and fitquite well to the target. In this case, bothaccuracy and precision has beenachieved. However, in practice, the Cscenario is often more frequent with anaverage batch composition close to thetarget but with varying differences be-tween batches. Scenarios B and D wherethe average batch composition does notfit the target, but the variation frombatch to batch are fairly consistent are al-so reported.

As the nutritionist and diet formulatordefine the nutrient specifications thatwill optimize animal performance andminimize feed cost, it is clear that anydeviation from these specifications willhave repercussions on animal perfor-mance.

Effect of raw material quality on feed costand animal performance

The effects of raw material quality onanimal performance depend on species,type of nutrient, and direction of the de-viation, i. e. surplus or deficiency. Someof these effects are shown in table 1.

Essential amino acids provided by rawmaterials or supplemented as crystallineamino acids to the feed have a verystrong influence on animal performanceand feed cost. As such, incorrectly as-sessing the amino acid content of rawmaterials will provoke costly deviationsof the final amino acid supply in the feed

Figure 2: The concepts of accuracy and precision represented by bull's-eyes.

Accurate andprecise

Precise Accurate Inaccurate andImprecise

A B C D



from target values. The cost of the for-mula will increase when there is a sur-plus on the amino acid contribution. Onthe other hand, a shortcoming in theamino acids will suppress animal perfor-mance.

By rectifying the amino acid content ofthe raw material in the formulation pro-gram one can see the change in feedcost. As an example, correcting a 5 %deviation in the essential amino acidcontent of soybean meal would reducebroiler feed cost by about 0.70 €/ton, as-suming current prices for major raw ma-terials and synthetic amino acids.

The effect on animal performances canbe equally important. For example, Fig-ure 3 shows the results of an experimentcarried out with broilers at KaposvarUniversity (Hungary; Lemme et al.,2003). The treatments consisted of abasal diet with four different levels ofDL-Met supplementation (0, 0.04, 0.08,and 0.12 %). Higher DL-Met supplemen-tation resulted in increased growth andbetter flock uniformity with a high per-centage of broilers between 1700 and1900 g.

The control of the raw material variability

In order to minimize the effect of rawmaterial variability on feed quality andlivestock production, producers usuallyset up quality control plans. It is funda-mental in these plans to decide about:the frequency of analysis for each rawmaterial; to establish the sampling proto-col; and to have appropriate means tostatistically evaluate the results of theanalyses.

a) Frequency of analyses:In order to define a proper frequency ofanalysis of a raw material, one shouldtake into account the contribution of theraw material to the total variability ofeach nutrient in the feed (standard devi-ation of the nutrient in the feed). As ageneral rule, the higher the inclusionlevel of a raw material and the higherthe variability of the nutrient in this rawmaterial, the higher should be the fre-quency of analysis.

Table 1: Effect of deviations in feed nutrient content on animal perform-ance and feed cost

Nutrients Real < Theoretical Real > Theoretical

Energy - q Intake/Feed conversion - qFeed cost- q Excretions - Q Intake- Q Animal production - Q Animal production - q Variability of flock - q Fat deposition

Minerals - Several effects depending on mineral and species: Cu in sheep, Ca and P in layers, etc.

Protein/ - QAnimal production - qFeed costAmino acids - q Variability of flock - qN excretion

3000

2500

2000

1500

1000

500

00 5 10 15 20 25 30 35 40 45 50

Age, days

1800 g achieved at:Basal diet: 41.5 d0.04 % DL-Met 34.8 d0.08 % DL-Met 33.2 d0.12% DL-Met 31.8 d

1800 g

Basal diet

0.04 % DL-Met

Figure 3: Broiler live weight development as a function of age and DL-Metsupplementation level (left) and coefficient of variation in the lotand percentage of broilers with a live weight between 1,700 and1,900 g (right; Lemme et al., 2003)

Body weight, g

1000

CV, standardized

to 1800 g body weight

1200 1400 1600 1800 2000 2200 2400 2600

Birds with

1800 ± 100 g body weight

basal diet:

0.04 % DL-Met

0.08 % DL-Met

0.12 % DL-Met

17.0 %

11.3 %

9.0 %

6.7 %

Basal diet:

0.04 % DL-Met

0.08 % DL-Met

0.12 % DL-Met

26 %

37 %

48 %

58 %



The calculation of the standard deviationof a nutrient in the feed can be donefrom the standard deviations of everyraw material included in the feed accord-ing to the following equation:

Then, the contribution of each ingredi-ent to the total variability can be calcu-lated as follows:

Knowing the standard deviation of thenutrients of each raw material is crucialfor the aforementioned calculations. Thisinformation can be derived from the feedmill archives of analytical results. If thefeed mill has not yet compiled analyticaldata or a new raw material source needsto be evaluated, it is advisable to step upthe sampling frequency and the analyti-cal efforts in order to compile a reason-able database.

b) Sampling protocol:In addition to the frequency of analysis,it is also necessary to establish a proper sampling protocol. Such a protocolshould define the procedure according towhich samples are taken in order tominimise the bias.

The sampling devices should be able tocatch any type of particle to avoid selec-tion processes that could distort the com-

position of the samples. They should alsobe able to take samples from any part ofthe lot, both bulk and bags.

In addition to the variability between dif-ferent lots of a raw material, there also isvariability within the lot (e. g. truck,compartment of ship). Therefore, it is es-sential to develop the correct samplingprocedure to obtain representative sam-ples.

One of the key points is to define thenumber of samples to be taken at the re-ception of the raw materials. In general,the higher the number of samples takenfrom a truck or bag delivery will result inhigher accuracy between the result ofthe analysis and the real nutrient con-tent of the raw material.

In theory, it is possible to estimate thenumber of samples to be taken fromeach lot of raw material to achieve goodcorrelation between the analyzed nutri-ent content of the sample and the actualnutrient content of the lot. Herrman(2002) described the equations necessaryfor such an estimation when raw materi-als are delivered in bags or bulk:

Delivery in bags:n = (N * S2) / ((N-1)D + S2)

Delivery in bulk:n = S2 * (t)2/(e)2

For example, if the aim is to analyze theCP content of a delivery of 100 bags offish meal (S2 = 0.7 according to previousfeed mill data) and the intended result ofthe analysis should not differ in morethan 0.5 units from the real value (e =0.5) with a 95 % security (t = 1.96) thatthe analytical result reflect the actual CPcontent, then the number of bags to besampled (n) would be: (100*0.7) / ((100-1)*( 0.52/(2*1.96))+0.7) = 10 bags.

The variance within the lot (S2) is thekey parameter that must be known be-

SD = (X1 x S1)2 + (X2 x S2)2 + ...

SD = Standard deviation of the nutrient in the feedSN = Standard deviation of the nutrient in the ”n” ingredientXn = Proportion of the ”n” ingredient in the feed

Contribution to the total variability(Xn x Sn)2

(X1 x S1)2 + (X2 x S2)2 + ...% = X 100

n = number of samples to be takenN = total number of bags in the lotS2 = variance of the nutrient inside the lotD = e2/(2 x t)e = accepted deviation between the result of the analysis and the real

composition.t = "t" statistic for a certain level of security



fore doing these calculations. Again,these data need to come from the analy-tical database of the feed mill. From timeto time, it may be of interest to collectand analyze a higher number of samplesfrom each lot in order to update thedatabase.

In practice, the number of samples takenfrom each truck or lot usually dependson other limiting factors such as: man-power, time, characteristics of the au-tosampler, etc.. In these cases, the formerequations can be used to know the possi-ble deviation that can be found betweenthe result of the analysis and the realcomposition (by fixing the "n" value inthe equation and discovering the "e" val-ue). This information can be valuable tomanage the resources in order to in-crease or decrease the number of sam-ples to be taken.

c) Data management and statisticalanalysis:

All analytical data should be archived to-gether with detailed information aboutthe respective raw material, i. e. suppliername, lot, date, origin, process, so thatcrucial informed decisions can be made.

A good software support system to man-age this large quantity of information isessential, as this allows for flexible datamanagement, graphic visualization andstatistical analysis. One example of a sys-tem already established to help with datamanagement is our AminoQ system(Fickler, 2002).

A system, such as AminoQ or similar, es-tablishes temporary graphs showing theresults of the analyses (Figure 1). Thesesystems can include alarm limits, UWLand LWL lines, or tolerance limits, UALand LAL lines, according to the standarddeviation of the samples. These graphsare useful to update the nominal valueand tolerance limits of the specificationcards, which are employed in the feedmill as references to purchase ingredi-ents.

Another advantage of using a systemsuch as AminoQ is the possibility of com-paring different origins and suppliersbased on the average content of certain

quality criteria (e. g. nutrients, toxins).Drawing the range of individual analysesagainst their frequency in a set of rawmaterial samples usually results in bell-shaped distribution curves (Gauss curve).The Gauss curves allow for a quick visu-alization of how variable the deliveries ofdifferent sources of, for example, soy-bean meal is (Figure 5). These compari-son help to make purchasing and formu-lation decisions as described below.

Main advantages of raw material qualitycontrol

a) Short term advantages: A good quality control has important ad-vantages beginning at the reception ofthe raw materials. More and more feedmills are being equipped with the mostadvanced NIR machines, which if fur-nished with the right calibration soft-ware, allow for rapid and accurate esti-mates of the nutrient content of manyraw materials before unloading. Basedon the results obtained from the analysisof the lot (truck), some decisions couldbe made:

– To refuse the lot. This should be con-sidered when the deviation of a speci-fied nutrient (CP, individual amino

Figure 5: Total sulfur amino acid content and standard deviation of a rawmaterial. Samples from two different suppliers.

Supplier 1

Supplier 2

0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5

Average 1 Average 2

Met + Cys %

t

t

t

t

S2

S1



acid, etc.) in relation to the average(nominal) value is too high, and cer-tainly before the load has been dis-charged.

– To negotiate a discount with the suppli-er. Often, to calculate the discount, it isassumed that the price of the ingredi-ent should diminish proportionally tothe nutrient content. However, themost appropriate method would proba-bly be to compare both scenarios withthe formulation program, i. e. nominalcomposition vs. real composition, tofind out what should be the new priceof the raw material to get the samefeed cost (parametric analysis).

– To distribute lots to different silos.Sometimes it can be economically fea-sible to separate a raw material accord-ing to its quality and store it as such.This would enable you to use bothqualities of a raw material in feed formulation as two different raw mate-rials. The main limitation to this ap-proach is often storage availability.

– To reformulate with the new composi-tion. This makes sense when the actualquality deviates significantly from theexpected value(s). In this case, it is im-portant to coordinate the change in theformulation and the switch in ingredi-ent quality in the feed mill.

b) Medium and long-term advantages:The routine analysis of the raw materialsalso allows for medium and long-termmanagement of the variability. Better in-formation about raw material variabilitycan become an additional criterion whencomparing ingredients or suppliers of thesame ingredient as well as during feedformulation.

– Categorization of suppliers. Typically,purchasers select suppliers with thelowest variability in their raw materials(Figure 5). Reciprocally, suppliers try toprovide high and consistent quality tothose feed producers. Over time thisleads to improved raw material qualitywith better consistency being delivered.

– Raw material assessment. Besides thenutrient content of the raw materials,their variability becomes also a relevantquality criterion. The variability will beconsidered when purchasing and dur-ing the formulation to define the rawmaterial inclusion level.

– Control of the feed variability. The feedvariability can be estimated from theraw materials (see above equations).This variability has to be taken into ac-count when deciding upon the appro-priate safety margins to be included inthe formulation software. The morefrequent the analysis and the updatingof the matrix, the lower the safetymargins required.

Management of raw material variability infeed formulation

In practice there are several ways to con-trol the variability via feed formulation:

a) Linear programming formulation(LP):

– Method 1:The matrix of the raw materials is up-dated according to the average nutrientcontent and an arbitrary safety marginis included in the specifications in or-der to compensate for the variability ofthe ingredients.

– Method 2:The matrix of the raw materials is up-dated according to the average nutrientcontent corrected for variation. Thisadjustment is done by taking into ac-count the standard deviation (SD) ofthe analyzed samples. Usually, the cor-rection is minus 0.5 SD, but correctionswith other multiples of SD are also pos-sible. The higher that the correction isin the matrix, then the higher theprobability that the real composition ofthe ingredient is equal to or better thanthe value in the LP matrix (Table 2).

This method doesn't require any mar-gin on the nutrient specifications tocorrect the variability of the ingredients



as nutrient variability is already ac-counted for in the ingredient matrix.

b) Non linear stochastic formulation(SF):

Similar to LP, stochastic formulation triesto optimize the inclusion rate of the dif-ferent ingredients to fulfill the nutrientspecifications of the formula at the low-est possible cost. However, in contrast,the SF allows, on a individual nutrientbasis, the feed percentage that will fulfillthe limits defined in the specifications tobe decided. In the SF, the matrix of theingredients includes the average compo-sition values and the standard deviationsfor each nutrient. Therefore, it is essen-tial to closely monitor ingredient qualityin order to maximize the benefit fromthis type of formulation.

As an example, Table 3 shows the effectof different formulation methods on theCP content and cost of one feed.

In "Method 0", which does not includeany safety margins or any corrections onthe matrix, only half of the producedfeed meets or exceeds the CP specifica-tions.

In "Method 1", the chosen safety margin(5 %) is too high and makes the feed tooexpensive. Nevertheless, the biggestproblem is that the ingredients are onlyvaluated by their average compositionwithout taking into account their vari-ability. This means that nutrient specsneed to be adjusted each time that differ-ent raw materials or the same raw mate-rials but with different variation areused.

In "Method 2", the nutritionist is aimingfor 69 % of the produced feed to meet orexceed the formula specifications. With

Table 2: Effect of multiples of SD on the probability that the actual nutrient content of an ingredient is equal to or betterthan the LP matrix value

Correction effects on the ingredient matrix (multiples of SD) 0.00 0.26 0.50 0.53 0.83 1.29 1.65 2.33

Probability that actual nutrient content is equal to or better 50 60 69 70 80 90 95 99than the value in the LP matrix (%)

Table 3: Feed composition and CP content according to linear and stochas-tic formulation methods*

Ingredients (%) Method 0 Method 1 Method 2 SF (50 %) SF (69 %)(69 %)

Corn 59.33 55.81 57.91 59.33 58.46

Soybean meal 22.35 25.35 23.55 22.35 23.09

Fat 4.38 4.92 4.60 4.38 4.52

Corn gluten meal 3.00 3.00 3.00 3.00 3.00

Meat and bone meal 10.00 10.00 10.00 10.00 10.00

Dicalcium phosphate 0.35 0.35 0.35 0.35 0.35

Salt 0.25 0.25 0.25 0.25 0.25

Correctors 0.25 0.25 0.25 0.25 0.25

DL-Methionine 0.09 0.07 0.08 0.09 0.08

% CP (Computer) 23.00 24.15 23.00 23.00 23.00

% CP (Real) 23.00 24.15 23.46 23.00 23.00

Theoretical Prob. (%)1 50 -- 69 50 69

Real Prob. (%)2 50 98 80 50 69

Cost, €/ton 177.69 180.21 178.70 177.69 178.31

* Method 0 (50 %): LP without safety margins (50 % probability to cover the CP specifications).Method 1: LP + 5 % safety margin in the CP specifications of the formula.Method 2 (69 %): LP with 0,5 x SD correction of the CP content of each ingredient (69 % probability to meet or exceed theCP specs)SF: Stochastic formulation to cover with a 50 % (SF (50 %)) or a 69 % probability (SF 69 %) the CP specifications.

1 Theoretical Prob.: Percentage of produced feed intended to fulfill the formula specifications 2 Real Prob. Percentage of produced feed that really fulfills the formula specifications

Source: Roush, W. B., Penn State University

this goal, he intuitively corrects the aver-age composition value of the matrix by0.5 SD (see also table 2). “Method 2"takes into account ingredient variabilityas the nutrient matrix of each ingredientis corrected according to the respectiveSD for CP.

However, the percentage of producedfeed that will actually fulfill these specifi-cations is not 69 %, but instead a highervalue which means that the feed costwill increase.



The SF may be the method with themost advantages:– Allows for decisions on accuracy and

individual nutrients, which will be thepercentage of produced feed that willcomply with the formula specifications(safety margin). The stochastic and thelinear formulations give identical re-sults when the chosen safety margin is50 % ("Method 0" vs. "SF (50 %)).

– Within a certain safety margin, the costis always the minimum.

– It promotes the employment of ingre-dients with lower variability

– The real feed composition compliesvery well with the composition in thecomputer and on the tag.

The SF method originated in the earlysixties (Van de Panne and Popp, 1963)but at the time, due to computationallimitations, linear programming was pre-ferred and the concept of "safety margin"was included to compensate for raw ma-terial variability. However, today, com-putational limitations are no longer anissue for SF making it possible to imple-ment this type of formulation (Brooke etal., 1996; Schrage, 2000).

However, the SF method also has somelimitations: it requires an exhaustivecontrol of the raw material variabilityand, sometimes, the proposed least costsolutions can be very expensive if manynutrients are subjected to high safetymargins.

The current role of the amino acids in feedquality control

Usually, protein is one of the most im-portant nutrients to consider in qualitycontrol of raw materials. However, oftenamino acids are not considered and/ornot analyzed. Table 4 describes the differ-ent possibilities to update the amino acidcontent of typical raw materials.

Some feed producers occasionally sendraw material samples to external labora-tories for chromatographic analysis. Nor-mally these samples come from lots thathave shown significant deviations fromthe expected CP content. This is an accu-rate method, but due to its high cost, it isnot useful for a routine analysis.

Another commonly used method is tocorrect the amino acid content of rawmaterials based on their CP contentwhich can be analyzed by wet chemistryor NIR. Once the CP has been analyzed,the estimation of the amino acids can bedone proportionally to the protein con-tent, or with the help of regression equa-tions that relate the amino acid content(y) with the CP content (x). The lattermethod is better because for a number ofimportant feed ingredients an increase ordrop in crude protein does not alwaysmean a proportional change in aminoacid content (Figure 6). The best methodfor estimating the amino acid content ofraw materials is NIR because it combinesaccuracy with quickness and low cost.

It is important to note that such analysesare only useful if the results are com-piled, evaluated and decisions are takenwith respect to purchasing, storage andfeed formulation. While there are an in-creasing number of feed producers whoregularly update the amino acid specifi-cations of their raw material matrices,there are still a large number of themdoing it only sporadically or worse not atall.

Many of the commercially available formulation software packages allow forequations to be written into the softwarethat automatically update some nutrientswhen others have been changed. By us-ing such equations, it is easy to adjust

Table 4: Possibilities to estimate the amino acid content of raw materials.

Method Quick Economic Accurate

Chromatography -- -- ***

Calculation based on CP content * (1) *** **** (2) ***

Direct estimation by NIR ** *** **

Fixed values from tables *** *** --

(1) CP determined by wet chemistry(2) CP estimated by NIRS

Sunflower MealWheat



the content of all relevant amino acidswhile updating only the CP content.Regular updates can make worthwhileimprovements in feed cost and/or ani-mal performance.

Table 5 shows the effect of updating theCP content alone (column "CP") or theCP and essential amino acids content ofwheat (column "CP + AAs") of a broilerformula. The initial formula was calcu-lated according to the average wheatcomposition given in Figure 1.

When the CP content of wheat is updat-ed, following a delivery of better qualitywheat, (region 1), and the feed is refor-mulated accordingly, the consumption ofwheat and amino acids increases. Ac-cordingly, the level of protein sources(fish meal and soybean meal) decreases,and the feed cost is reduced by 10 €/ton.However, the real amino acid supply isunnecessarily increased.

When the essential amino acid contentof the wheat is updated in addition tothe CP content (column "CP + AA,s"),synthetic amino acid consumption againincreases but to a lesser extent than inthe CP diet. Also, the supply of essentialamino acids is optimized (i. e. exactly according to specifications), and there isan extra reduction in the feed cost of 3 €/ton resulting in a total savings of 13 €/ton.

To look at this another way - if a poorquality wheat was employed, for exam-ple the wheat from region 3, with a 7.6 % CP content, the effect would bejust the opposite; the column "CP"would have a smaller cost than the col-umn "CP + AAs," but the total essentialamino acid supply would be lower thanrequired. As a result, animal perfor-mances would be compromised. There-fore, the feed producers that do not up-date the amino acid content of the rawmaterial matrix require bigger safetymargins in the formula specifications inorder to avoid possible negative effectson animal performances.

Figure 6: Lysine percentage in the crude protein (CP) of different raw materials (taken from AminoDat 2.0, examples are not exhaustive)

9

8

7

6

5

4

3

2

1

5 25201510 30 35 40 45 50

Soybean MealBarley

Peas

CP %

Lysi

ne

inth

eC

P(%

)

Table 5: Effect of reformulating broiler diets based on higher qualitywheat (higher content of CP and amino acids) on CP or both CPand essential amino acids (CP + AAs)

Reformulation according to:CP CP + AAs

Wheat, g/kg q70 q70

Soybeanmeal, g/kg Q40 Q30

Fish meal, g/kg Q45 Q45

DL-Methioninw, g/kg q1 q0.6

L-Lysine, g/kg q4 q3

L-Threonine, g/kg q1.6 q0.9

CP total, g/kg – –

Lysine total, g/kg q0.5 –

Methionine total, g/kg q0.3 –

Threonine total, g/kg q0.7 –

Cost, €/ton Q10 Q13

Cost Difference = 3 €/ton

NU

TRIE

NTS

(in

clu

sio

nd

iff e

ren

ce)

Ing

red

ien

ts(i

ncl

usi

on

dif

fere

nce

)



References

Brooke, A., D. Kendrick, and A. Meeraus(1996): GAMS Release 2.25: A user's guide.GAMS Development Corp., Washington D.C.

Fickler, J. (2002): AminoQTM – A power toolfor lab data management. AminoNews 03: 7 – 10.

Herrman, T. (2002): Sampling: Statistical andEconomic Analysis. Kansas State University.MF-2506. May 2002.

Lemme, A., J. Tossenberger, and A. Petri(2003): Impact of Dietary Methionine on Uni-formity in Broiler Production. 14th Eur. Symp.Poultr. Nutr. (Lillehammer, Norway).

Schrage, L. (2000): Optimization modelingwith LINGO. LINDO Systems, Chicago, III.

Van de Panne, C., and W. Popp (1963): Mini-mum cost cattle feed under probabilistic pro-tein constraints. Management Sci.: 405-430.

Carlos Dapozaemail: [email protected]



Isoleucine in Pig Nutrition

Pigs

501020

Key information

• Spray-dried blood products encourage maximum feed intake and performance inthe period immediately after weaning.

• Spray-dried blood products show relativelyhigh concentrations of leucine, lysine and va-line, but a limited concentration of isoleucineand methionine.

• Increasing availability of supplementalamino acids allows reducing the crude pro-tein (CP) level in diets while maintaining ad-equate essential amino acid supply and ani-mal performance.

• Reduced CP diets also benefit the health ofpigs by reducing the incidence of diarrhoeaand the formation of toxic compounds suchas amines and ammonia.

• Low CP diets supplemented with aminoacids or diets containing blood productsmay be limiting in isoleucine and may re-quire isoleucine supplementation.

• Research evaluating branched-chain aminoacid balance and the optimal level of bloodco-products that can be used is limiting, somore research is needed in these areas.

Introduction

With the wide range of feed ingredientsutilized in pig feeds, the advancementsin growth potential (genetics, manage-ment, nutrition, sanitation, etc.) and theeconomic availability of supplementalamino acids, modern feeding strategiesallow producers to reduce the dietary CPlevel in feeds, while maintaining ade-quate essential AA supply and conse-quently, animal performance. The aim ofthis paper is to review the need forisoleucine (ILE) supplementation in dietscontaining spray-dried blood productsand/or reduced CP level in diets forgrowing-finishing pigs.

Spray-dried blood products are low in methionine and isoleucine

Starter pigs, especially those weaned atless than 18 days of age, need a diet ofhigh nutrient density, high palatabilityand high digestibility. Meeting theseneeds requires very expensive ingredi-ents. Ingredient choice has as big an im-pact on performance during the weanerperiod as does the level of nutrients pro-vided.

Several protein sources are often used instarter pig diets to meet the amino acidrequirement and to stimulate feed in-take: spray-dried plasma, spray-driedblood cells, spray-dried blood meal, fishmeal, skim milk, whey-protein concen-trate and further processed soy products(soy concentrate or isolate). The specificprotein sources used in starter pig diets,however, depend on its availability andpricing relative to growth performancebenefits. Currently, the only proteinsource considered essential in this diet isspray-dried plasma. Although it is ex-pensive, spray-dried plasma seems nec-essary to encourage maximum feed in-take in the period immediately afterweaning (Hansen et al., 1993b and Katset al., 1994a). Increasing the level ofspray-dried plasma from 5 % to 15 % inthe diet for segregated early weaned(SEW) pigs resulted in a linear increasein pig performance.

An alternative to plasma for inclusion in-to the SEW diet is spray-dried bloodmeal, which has a very high protein con-tent (85 % to 95 %) and thus can beused in small quantities as a concentrat-ed amino acid source (Hansen et al.,1993b; Kats et al., 1994a; Kats et al.,1994b). However, both spray-dried bloodmeal and plasma are deficient in methio-nine, which becomes a limiting aminoacid when greater than 5 % spray-driedblood products are included in the diet(Kats et al., 1994a). Consequently, it is



critical that crystalline methionine beadded to starter pig diets for optimumperformance (Owen et al., 1995a,b). Be-cause of the demand for spray-dried ani-mal plasma, very little blood meal is uti-lized in starting pig diets.

Spray-dried porcine plasma, a co-productof blood processing, is produced by col-lecting whole blood at the slaughterplant, adding an anticoagulant, and aftercooling, separating the plasma by cen-trifugation (Figure 1). After the spraydrying process, the resultant product is afree flowing, light colored product withexcellent protein/amino acid characteris-tics. Spray-dried porcine plasma hasbeen consistently shown to be an excel-lent protein source for young pigs. A‘co’ co-product of this process, spray-dried blood cells (SDBC), can also be uti-lized in piglet diets. The amino acid char-acteristics of these two products showrelatively high concentrations of leucine,lysine and valine, but a limited concen-tration of isoleucine and methionine(Table 1). It is therefore important thatdiets are adjusted to maintain a properlevel of these two amino acids. Owen etal. (1995a,b) demonstrated that a posi-tive response was obtained when dietscontaining porcine plasma are furnishedwith crystalline methionine while Kerr etal. (2004a,b) demonstrated positive re-sponses to crystalline isoleucine whendiets contained SDBC.

Use of supplemental amino acids is nutrition-ally useful and economical

The inclusion of crystalline amino acidsin pig diets is nutritionally useful andeconomical. Lysine, methionine, threo-nine and tryptophan are used to differ-ent degrees in practical pig diets. Theyhelp to provide the correct amino acidbalance while helping to limit vegetableprotein products and crude protein level.Reducing the total amount of proteinthat must be digested by the digestivetract of the pigs reduces the level of un-desirable end products from protein di-gestion and decreases the risk of diar-rhoea. This holds especially true for theimmature digestive tract of piglets. Also,high and imbalanced protein levels havebeen shown to reduce feed intake.

Reducing dietary CP level in the diet hasbeen reported to limit the frequency andthe severity of digestive problems inpiglets (Prohaszka and Baron, 1980;Danielsen 1984; Ball and Aherne, 1982,

Figure 1: Composition of whole blood

LIQUIDS 82 %

LIQUIDS 70 %LIQUIDS 92 %

CELLS – 48 %PLASMA – 52 %

WHOLE BLOOD

SOLIDS8 %

SOLIDS18 %

SOLIDS30 %

Table 1: Protein and amino acid composition of spray-dried blood products

Spray-dried AppeteinTM*

animal blood cells Spray-Dried(AP 301GTM*) Animal Plasma

Crude Protein (%) 92.0 77.0

Amino Acids (%) Ratio to Ratio to RecommendedLys Lys ratio to Lys

Lysine 9.0 100 6.5 100 100

Methionine 0.8 9 0.7 11 35

Cystine 0.6 7 2.7 42 --

Threonine 3.6 40 4.7 72 65

Tryptophan 1.2 13 1.3 20 21

Isoleucine 0.6 7 2.8 43 60Arginine 4.0 4.5

Leucine 13.4 7.5

Valine 9.2 5.1

Histidine 7.5 2.7

Phenylalanine 7.1 4.4

Tyrosine 2.2 3.5

Glycine 4.7 2.9

Serine 4.4 4.5

Proline – 12.6

Alanine 7.6 4.0

Aspartic acid 11.4 7.6

Glutamic acid 8.7 11.3

*APC, Inc., IA, USA



1987). Sources of growth substrates forgastrointestinal microflora come fromthe diet as undigested feed protein andendogenous protein which provide bac-teria with nitrogen while undigested feedcarbohydrates (e.g., non-starch polysac-charides) provide bacteria with carbon. Alarger microbial load in the gastrointesti-nal tract may have implications on im-mune function, is associated with odorgeneration from swine production facili-ties, and may harbor potential pathogen-ic bacteria such as Coli, Salmonella andClostridium. By reducing the dietaryprotein level, the metabolism of the bac-teria community can be altered to reducetheir potential detrimental impact to theanimal and the environment. At thesame time, however, it is still importantto feed a diet with a well balanced aminoacid profile to ensure optimum perfor-mance and carcass lean deposition.

The effects of reducing the dietary CPlevel associated with AA supplementa-tion on growth performance, N-excre-tion, water consumption, urine produc-tion and feces consistency in piglets wasstudied by Le Bellego and Noblet (2002).Feed intake (Table 2) was the lowestwith Diet 1 (959 g/d) and similar for Diets 2, 3, and 4 (1039, 1061 and 1048 g/d,respectively). The lower feed intake withpiglets fed the highest CP diet agreeswith observations of Hansen et al.(1993a) and Jin et al. (1998). Such diets,providing AA exclusively as proteinbound AA, result in excess and (or) im-balanced AA that may be detrimental forfeed intake in young animals (Harper etal., 1970; Henry, 1985; Henry and Seve,1991). Thus, limiting protein contentwhile balancing dietary AA appears to bean effective solution to maximize feed,nutrient and energy intakes in piglets.

Neither weight gain (666 g/d, on aver-age) nor feed efficiency (1.55, on aver-age) were affected by dietary treatment(Table 2). Interesting enough, the totalweight of internal organs including bloodand empty gastro-intestinal tract (% ofempty BW) was higher with Diet 1 thanDiets 2, 3 and 4, resulting in a lower car-cass yield for the animals fed Diet 1 com-pared with the other treatments (datanot reported). The piglets fed Diet 1 also

Table 2: Effect of dietary crude protein level on performance, nitrogen excretion, water intake, urine production and feces consistency ofpiglets (Le Bellego and Noblet, 2002)

had a higher water content and a lowerlipid and energy content than those fedDiets 2, 3 and 4 (data not shown).

The N-excretion over the total experi-ment was reduced by 42 % from Diet 1to Diet 4 (Table 2). The present resultsconfirm that reducing the dietary CPcontent is an effective strategy to reduceN-excretion. The reduction in N-excre-tion of 42 % between Diets 1 and 4equates to an 8 % reduction in N-excre-tion per percentage point of CP reduc-tion in the feed when data are adjustedfor identical feed consumption over thetotal experiment (1029 g/d). This valueis slightly lower than the 10 % value re-ported for growing pigs by Dourmad etal. (1993) and Le Bellego et al. (2001) inbalance trials and Le Bellego et al. (2002)in a growth trial. The reduction of N-in-take with the low CP diets did not affectN-retention (Table 2) by the animals(17.6 g/d on average).

The reduction of the CP level in the feedalso resulted in a numerical reduction ofwater consumption and urine produc-tion of 15 and 36 %, from Diet 1 to Diet4, respectively, or about 3 % and 7 %per percentage point reduction of CP inthe feed, respectively (Table 2). These re-

Diet 1 2 3 4Dietary CP (%) 22.4 20.4 18.4 16.9

Body weight (kg)Initial 11.7 12.0 11.8 12.0

Final 26.0 26.8 27.2 26.8

Feed intake (g/day) 959a 1039b 1061b 1048b

Weight gain (g/day) 642 661 690 663

Feed/gain (kg/kg) 1.50 1.58 1.54 1.58

Total nitrogen excretion (g/day) 10.7 a 9.4 a 6.8 b 5.1 c

Nitrogen retention (g/day) 17.8 17.7 18.5 15.6

Water consumption (g/day) 1941 1887 1867 1645

Urine (g/day) 757 643 625 481

Feces consistency (%1)Hard 81.9 82.0 95.4 89.0

Soft 14.7 14.5 4.1 9.0

Liquid 3.4 3.5 0.5 2.0

Diets were formulated to contain about 10.4 MJ NE/kg and 1.01 g stand. dig. lysine/MJ NE. Ratios of digestible threonine,methionine + cystine, tryptophan, isoleucine and valine were at least at 65, 60, 19, 60 and 70 % of the digestible lysine supply, respectively.

1 Days with hard, soft or liquid feces in percent of total number of days in the experiment.

a,b,c Different superscripts indicate significantly different means (p<0.05).



sults are in agreement with those of Fré-maut (1992) and Pfeiffer et al. (1995).

The measurements on feces consistencyrevealed no significant effect of the dietdespite a numerically lower percentageof days with soft or liquid feces with Diets 3 and 4 compared to Diets 1 and 2(Table 2). The minor effects on diarrhoeaand performance are probably related tothe relatively good sanitary conditions inthe present experiment. However, incommercial situations, less favourablesanitary conditions are common and agreater effect of low CP diets on the oc-currence of diarrhoea and on perfor-mance can be anticipated (Göransson etal., 1995).

Isoleucine Requirements and Ratios of Swine

Research evaluating isoleucine require-ments (Table 3) of pigs is dated, sparse,and difficult to interpret. Mitchell et al.(1968a, b) utilized a casein-based dietand Brown et al. (1974) utilized agelatin-based diet to estimate the iso-leucine requirement using nitrogen re-tention or plasma isoleucine, but neitherreported performance data. In papers re-porting pig performance, semi-purifieddiets containing large amounts of cornstarch with either blood flour (Brinegaret al., 1950; Becker et al., 1957, 1963;Bravo et al., 1970; Oestemer et al., 1973)or herring meal (Henry et al., 1976) havebeen utilized, with only four papers uti-

Table 3: Digestible isoleucine requirement estimates for swinea

Body Weight, kg CP ADG ADFI Ile g Ile/ mg Ile/Initial Final Gender % g g % day g gain Reference

5.6 8.4 NA 18.2 505 580 0.59 3.42 6.78 James et al., 2001

4.7 10.2 NA 22.2 183 360 0.61 2.20 12.02 Becker et al., 1963

5.8 15.7 Barrow 14.4 331 534 0.43 2.30 6.95 Oestemer et al., 1973

11.4 23.5 Mixed 16.7 578 993 0.55 5.46 9.95 Bergstrom et al., 1997

15.1 27.7 NA 13.4 467 939 0.38 3.57 7.64 Becker et al., 1957

18.2 34.9 NA 21.5 604 1,159 0.55 6.37 10.55 Brinegar et al., 1950

18.0 40.0 Mixed 17.0 685 1,250 0.50 6.25 9.12 Lenis and van Diepen, 1997

20.5 41.5 Barrow 15.8 690 1,597 0.27 4.31 6.25 Bravo et al., 1970

25.0 55.0 Gilt 17.5 630 1,594 0.35 5.58 8.86 Taylor et al., 1985

44.6 94.4 NA 13.4 590 1,780 0.29 5.16 8.77 Becker et al., 1963

aIngredient digestibility estimates from Southern, 1991. NA = not available.

lizing more practical-type ingredients(Taylor et al., 1985; Bergstrom et al.,1997; Lenis and van Diepen, 1997;James et al., 2001).

To complicate matters further, currentgenotypes are growing faster, producecarcasses with a greater percentage oflean meat, are marketed at heavier bodyweights, and have a lower appetite thanpigs utilized in many of the studies citedabove. As such, NRC (1998) recommen-dations for isoleucine were arrived at fac-torially using ideal amino acids ratios(Wang and Fuller, 1989; Chung and Baker, 1992).

With the misconception that isoleucine isadequate in common feedstuffs combinedwith limited availability of feed-gradeisoleucine, little information regardingisoleucine needs in swine has been gen-erated. However, recent research fromLiu et al. (1999, 2000a,b) suggested thatisoleucine may be among the limitingamino acids in today’s genotypes fed re-duced-protein diets. In addition, wide-spread commercial availability of lysine,methionine, threonine and tryptophan,an ever increasing pressure to lower ni-trogen excretion associated with swineproduction, and recent volatility of pro-tein ingredients makes the understandingof the isoleucine requirements and ratiosin swine of critical importance.

Recently, a coordinated research effortutilized SDBC in the development of an



isoleucine-deficient diet from which fu-ture isoleucine requirement and ratiostudies could be conducted (Kerr et al.,2002, Kerr et al., 2004a, Parr et al., 2003,2004). From these studies a series ofisoleucine requirement experiments wereconducted in starter (7 to 11 kg), grower(25 to 45 kg) and finishing (87 to 100 kg)pigs. In all cases, the basal isoleucine-de-ficient diet has proved to be fully effica-cious when surfeit crystalline isoleucinewas supplemented to the diet.

For 7 to 11 kg pigs, diets contained corn,soybean meal, dried whey, fish meal, and7.5 % SDBC. Performance data is shownin Tables 4 and 5 (Kerr et al., 2004b).

Overall the data suggested an apparentdigestible isoleucine requirement of 0.68 % or an apparent digestible iso-leucine:lysine ratio of 0.61 in pigs from 7to 11 kg, both of which are higher thancurrent recommendations.

For growing pigs, a corn-based diet with3.2 % soybean meal and 7.5 % SDBCwas utilized with data shown in Table 6(Parr et al., 2003).

The results from these experiments sug-gest that the true digestible isoleucine re-quirement of 25 to 45 kg pigs is 0.50 %,compared with 0.45 % estimated by NRC(1998).

For finishing pigs, an all corn diet with5.0 % SDBC (no soybean meal) was uti-lized with data shown in Table 7 (Parr etal., 2004).

The results from finishing pigs (Table 7)are more difficult to interpret. Aberrantgain resulted for pigs fed the secondtreatment such that the first two treat-ments had similar weight gain (541 ver-sus 483 g/d), but each of these were sig-nificantly different from the final threediets. In general, gain and feed efficiencyseemed to plateau around 0.31 % truedigestible isoleucine, with gilts having anumerically higher plateau than barrows(data not shown as the interaction wasnot significant). Plasma urea nitrogendata was extremely erratic. In gilts, noapparent plateau in plasma urea N con-centration was reached, even at the

Table 4: Graded levels of isoleucine for growing pigs in 1.25 % digestiblelysine diets containing spray dried blood cells, Experiment 1a

(Kerr et al., 2004b)

Dietary isoleucine, % Performance Criteria Plasma ureaTotal App. il. dig. ADG, g ADFI, g G:F, g/kg N, mg/dL0.56 0.47 149 267 560 29.6

0.62 0.53 181 281 641 27.8

0.68 0.59 254 348 730 24.8

0.74 0.65 310 401 772 24.2

0.80 0.71 321 420 767 24.5

0.86 0.77 317 412 769 23.8

0.92 0.83 305 403 755 25.0

Pooled SEM 6.8 8.7 11.3 0.98

Contrast (P-value)

Linear 0.01 0.01 0.01 0.01

Quadratic 0.01 0.01 0.01 0.01a Average initial and final weights were 6.6 and 10.9 kg, respectively.The trial lasted 16 d with 12 replicates per

treatment and 20 pigs per pen.

Table 5: Graded levels of isoleucine for starting pigs in 1.10 % digestiblelysine diets containing spray dried blood cells, Experiment 2a

(Kerr et al., 2004b)

Table 6: Graded levels of isoleucine for starting pigs in 0.95 % digestiblelysine diets containing spray dried blood cellsa (Parr et al., 2003)

Dietary isoleucine, % Performance CriteriaTotal App. il. dig. ADG, g ADFI, g G:F, g/kg0.46 0.37 52 165 318

0.55 0.46 111 213 520

0.64 0.55 207 351 589

0.73 0.64 258 365 708

0.82 0.73 246 350 704

0.91 0.83 260 359 725

Pooled SEM 5.9 8.2 9.9

Contrast (P-value)

Linear 0.01 0.01 0.01

Quadratic 0.01 0.01 0.01a Average initial and final weights were 6.6 and 9.9 kg, respectively.The trial lasted 16 d with 12 replicates per treatment

and 22 pigs per pen.

Dietary isoleucine, % Performance Criteria Plasma ureaTotal True digestible ADG, g ADFI, g G:F, g/kg N, mg/dLb

0.42 0.38 459 996 461 12.11

0.46 0.42 602 1149 524 10.71

0.50 0.46 687 1288 533 10.05

0.54 0.50 695 1456 477 8.49

0.58 0.54 729 1471 496 8.70

0.62 0.58 725 1465 495 -

Pooled SEM 38 101 53 0.52

Contrast (P-value)

Linear 0.01 0.01 > 0.10 0.01

Quadratic 0.02 0.02 > 0.10 > 0.10a Average initial weight was 27 kg.The trial lasted 21 d with 4 replicates per treatment and 5 pigs per pen.

b Data from an additional experiment representing five barrows (average initial BW of 26.4 kg) and five gilts (average initialBW of 25.5 kg), each in a 5x5 Latin square design.



highest isoleucine level, while barrowsshowed that the plasma urea nitrogendecrease with increasing isoleucine wasnot significant (data not shown). Conse-quently, the authors based their require-ment estimates on the growth study. The inability of determination of theisoleucine requirement by plasma ureanitrogen is supported by Dean et al.(2004, 2005) due to the dramatic incre-mental increase in daily feed intake asdietary isoleucine is increased.

Recently, research at Louisiana StateUniversity (Dean et al., 2004) suggestedthe true digestible isoleucine require-ment for 80 to 120 kg barrows was notless than 0.36 % while research at theUniversity of Missouri (Kendall et al.,2004) estimated the true digestibleisoleucine requirement for 91 to 117 kgbarrows was also near 0.36 % when us-ing a corn based diet containing 5 % SDBC.

As most requirement estimates reportedabove were above NRC (1998) estimates,one could question that the use of SDBCare causing potential branched-chainamino acid antagonisms (Harper et al.,1984; Block, 2000) and therefore elevat-ing the need for dietary isoleucine. Inthe past, however, most experimentsshowing such antagonisms have usedpurified or semi-purified diets (Oestemeret al., 1973; Henry et al., 1976; Langerand Fuller, 2000). In contrast, using abarley-based diet, Taylor et al. (1984,

Table 7: Graded levels of isoleucine for finishing pigs in 0.74 % digestiblelysine diets containing spray dried blood cellsa (Parr et al., 2004)

1985) suggested that a leucine:isoleucineratio of 4.0 had no detrimental effect onpig performance at low isoleucine levels,and at higher levels of isoleucine, a 4.5ratio was without effect. Likewise, Ed-monds and Baker (1987) showed that upto 4 % supplemental leucine did not af-fect pig performance when added to atypical corn-soybean meal-based diet.Due to the possibility that the use of SDBC overestimates the actual requirementof isoleucine, researchers at LouisianaState University are currently evaluatingthe impact of leucine and valine addi-tions to corn soybean meal diets. Datasuggests that the ratios of branched-chain amino acids in previous experi-ments were not the cause of feed intakeand growth depressions when a corn-SDBC diet was fed. However, differencesin levels of dietary crude protein, aminoacid composition, and sources of aminoacids (protein-bound or crystalline) maystill be playing a role in branched-chainmetabolism and subsequent require-ments for these amino acids (Dean et al.,2004). Consequently, additional researchis needed to evaluate branched-chainamino acid balance and the optimal levelof blood co-products (SDBC) that can beused in North American and Europeantype diets fed to swine.

Evaluation of isoleucine dose-response dataand implications for commercial feed formu-lation

The response in performance to a limit-ing nutrient can best be described by ex-ponential regression analysis (Schutteand Pack, 1995). The regression curvesfacilitate the calculation of the most eco-nomical dietary amino acid level in thatthey predict performance for each incre-mental step of amino acid supplementa-tion following the law of diminishing re-turns. The feed cost per kg weight gainwill decrease to the point where the rela-tive increase in cost from adding oneunit crystalline isoleucine to the feedequals the revenues from relative im-provement in animal performance. Inorder to determine this point, perfor-mance data have to be combined withactual cost of both feed and supplement-ed isoleucine.

Dietary isoleucine, % Performance Criteria Plasma ureaTotal True digestible ADG, g ADFI, g G:F, g/kg N, mg/dLb

0.28 0.25 541 1647 316 9.5

0.30 0.27 483 1210 406 9.2

0.32 0.29 652 1538 432 9.2

0.33 0.31 752 1819 452 8.5

0.35 0.33 719 1683 446 7.7

Pooled SEM 44 144 41 0.48

Contrast (P-value)

Linear 0.003 0.15 0.04 0.006

Quadratic 0.93 0.31 0.23 0.28a Average initial weight was 87 kg.The trial lasted 16 d with 6 replicates per treatment and 4 pigs per pen.

b Data from an additional experiment representing five barrows (average initial BW of 88 kg) and five gilts (average initialBW of 89 kg), each in a 5x5 Latin square design. Diets contained 0.63 % total lysine and true digestible isoleucine concen-trations of 0.22, 0.24, 0.26, 0.28, and 0.30 %.



For the present example, cost of thebasal feed without isoleucine supple-mentation was set at 290 US$ per tonand L-Isoleucine was set at 30.0 US$ perkg. Weight gain and feed conversion responses of pigs (7 -11 kg BW) to grad-ed dietary levels of isoleucine are givenin Figure 2.

The cost per kg feed and feed cost per kgweight gain were calculated for the dietary isoleucine levels covered in theexperiment by Kerr et al. (2004b) basedon regression curves for performanceand aforementioned price assumptions.The calculations can easily be done witha spreadsheet software. The followingequation was used:

Cost per kg weight gain = feed conversion ratio * cost per kg feed.

At the given set of performance andprice conditions, feed cost per kg weightgain reached a minimum at an ileal di-gestible level of 0.62 % isoleucine (Figure 3).

Price changes for supplemental aminoacids affect the economic optimum levelfor dietary isoleucine. Figure 4 shows theeconomic optimum dietary isoleucinelevel for L-Isoleucine prices of 30.0, 20.0and 10.00 US$ per kg. The greatly vary-ing price for L-Isoleucine results in mosteconomic levels of 0.62, 0.65 and 0.70 %isoleucine in the diet.

Formulation example considering a ratio ofILE to LYS of 60 : 100

Kerr et al. (2004b) determined an opti-mum ILE: LYS ratio for starting (6 to 11 kg) pigs based on pig performance andplasma urea nitrogen (PUN). Based onthe an average of all performance vari-ables and plasma urea nitrogen, the re-sults suggest the apparent digestibleisoleucine requirement is 0.68 % and theILE : LYS ratio is 0.61. Assuming that thisratio is also sufficient for growing-finish-ing pigs, the question is: At what dietarycrude protein level will isoleucine be-come limiting considering a minimumratio of ILE : LYS of 60 : 100?

Figure 2: Weight gain and feed conversion response of piglets (7 – 11 kg BW) to graded levels of dietary isoleucine (adapted from Kerr et al. 2004b)

Weight gain (g/d)350

330

310

290

270

250

230

210

190

170

150

130n

n

n

n

n n

n

Ileal dig. ISO content (% of diet)

0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85

y = 136.8 + 201.3 · (1 - e-7.55 · (ISO - 0.47))

y = 1.80 - 0.51 · (1 - e-13.56 · (ISO - 0.47))

n

n

n

n nn

n

0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85

Ileal dig. ISO content (% of diet)

Feed conversion ratio

1.80

7.70

1.60

1.50

1.40

1.30

1.20

Figure 3: Effect of ileal digestible isoleucine content in the diet on feedcost per kg weight gain (US$)

t

0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85

Ileal dig. Isoleucine content (% of diet)

0.73

0.71

0.69

0.67

0.65

0.63

0.61

0.59

0.57

Assumptions:Cost of unsupplemented diet: 0.40 US$/kgCost of L-Isoleucine: 30 US$/kg

Minimum cost at 0.62 % Isoleucine

Feed cost per kg weight gain (US$/kg)



Figure 4: Effect of varying L-Isoleucine price on economic optimum dietary Isoleucine content

In Tables 8 and 9, the results of least costformulations are shown for EU and USdiets, respectively. EU diets were basedon barley, wheat and soybean meal,whereas US diets are based on corn andsoybean meal. Diets were formulated forpigs in the body weight ranges of 25 – 40kg, 40 – 70 kg and 70 – 115 kg. Ratios ofstandardized digestible Met+Cys, threo-nine and tryptophan to lysine were atleast 60, 63 and 18 to 100 (25 – 40 kgBW), 62, 65 and 19 to 100 (40 – 70 kgBW) and 65, 70 and 19 to 100 (70 – 115kg BW), with Met : LYS at 33 : 100.Least-cost formulations were conductedusing actual EU and US feed ingredientsprices and an L-Isoleucine price of 30 US$ / kg. A minimum ratio of ILE :LYS of 60 : 100 was considered in theformulas.

Results of least-cost formulation will de-pend on ingredient prices. Under the giv-en price scenarios for the EU, dietarycrude protein can be reduced down toabout 17.0, 16.0 and 14.5 % for bodyweight ranges of 25 – 40 kg, 40 – 70 kgand 70 – 115 kg, respectively, beforeisoleucine gets limiting (Table 8). Consid-ering US feed ingredient prices, dietary

t

t

tt

tt

ttttttt tttt tttttttttttttttt ttt

n

n

ll

n

n

n

n

nn

nn

nn

n n n n n n n n n n n n n n n n n n n n n n n n n n n

0.75

0.70

0.65

0.60

0.55

0.50

0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85

Ileal dig. Isoleucine content (% of diet)

Feed cost per kg weight gain (US$/kg)

Cost of L-Isoleucine: 30 US$/kgMinimum cost at 0.62 % Isoleucine

Cost of L-Isoleucine: 20 US$/kgMinimum cost at 0.65 % Isoleucine

Cost of L-Isoleucine:10 US$/kg Minimum costat 0.70 % Isoleucine

Table 8: Effect of ILE to LYS ratio on dietary crude protein content:European-type diets*

Body weight (kg)Ingredient (%) 25 – 40 40 – 70 70 – 115Wheat 40.00 45.00 45.00

Barley 39.24 39.37 43.39

Soybean meal, 44 % 15.46 11.78 7.48

Soybean oil 1.46 0.01 –

Vitamin/Mineral-Premix 3.27 3.30 3.61

L-Lys-HCl 0.39 0.36 0.35

DL-Methionine 0.08 0.06 0.04

L-Threonine 0.10 0.10 0.12

L-Tryptophan – 0.01 –

Nutrients (%)ME (MJ/kg) 13.5 13.2 13.12

(kcal/kg) 3230 3150 3140

Crude Protein 17.0 16.0 14.5

min ratios min ratios min ratios

stand. dig. Lys 0.90 100 0.81 100 0.71 100

stand. dig. Met 0.30 33 0.27 33 0.23 33

stand. dig. M + C 0.56 60 0.53 62 0.47 65

stand. dig.Thr 0.57 63 0.53 65 0.50 70

stand. dig.Trp 0.17 18 0.17 19 0.14 19

stand. dig. Ile 0.55 60 0.50 60 0.44 60

* Basis: EU ingredient prices, summer 2005.



crude protein can be reduced down toabout 16.5, 15.5 and 14.0 % for bodyweight ranges of 25 – 40 kg, 40 – 70 kgand 70 – 115 kg, respectively, beforeisoleucine becomes limiting (Table 9). In-creasing availability of supplementalamino acids allows reducing the crudeprotein level in diets while maintainingadequate essential AA supply and animalperformance.

Dourmad, J. Y., Y. Henry, D. Bourdon, N. Quiniou and D. Guillou(1993): Effect of growth potential and dietary protein input ongrowth performance, carcass characteristics and nitrogen output ingrowing-finishing pigs. In: M. W. A. Verstegen, L. A. den Hartog, G.J. M. Kempen, and J. H. M. Metz (Ed.) Nitrogen flow in pig produc-tion and environmental consequences: Proceedings of the First Inter-national Symposium, Wageningen (Doorwerth), 206–211. Centre forAgricultural Publishing and Documentation (PUDOC), Wageningen,Netherlands.

Edmonds, M. S., and D. H. Baker (1987): Amino acid excesses foryoung pigs: effects of excess methionine, tryptophan, threonine orleucine. J. Anim. Sci. 64: 1664-1671.

Frémaut, D. (1992): A study of the requirements for amino acids ofBelgian growing pigs (20–60 kg body weight) in relation to produc-tion and environment. Katholieke Universiteit, Leuven, Belgium.

Göransson, L., S. Lange and I. Lönnroth (1995): Post weaning diar-rhoea: focus on diet. Pig News Inform. 16: 89N – 91N.

Hansen, J. A., D. A. Knabe and K. G. Burgoon (1993a): Amino acidsupplementation of low-protein sorghum-soybean meal diets for 5- to20-kilogram swine. J. Anim. Sci. 71: 452-458.

Hansen, J. A., J. L. Nelssen, R. D. Goodband and T. L. Weeden(1993b): Evaluation of animal protein supplements in diets of early-weaned pigs. J. Anim. Sci. 71: 1853-1862.

Harper, A. E., R. H. Miller, and K. P. Block (1984): Branched-chainamino acid metabolism. Ann. Rev. Nutr. 4: 409-454.

Harper, A. E., N. J. Benevenga and R. M. Wohlhueter (1970): Effectsof ingestion of disproportionate amounts of amino acids. Physiol. Rev.50: 428–558.

Henry, Y. (1985): Dietary factors involved in feed intake regulation ingrowing pigs: A review. Livest. Prod. Sci. 12: 339–354.

Henry, Y., P. H. Duee and A. Rerat (1976): Isoleucine requirement ofthe growing pig and leucine-isoleucine interrelationship. J. Anim.Sci. 42: 357-364.

Table 9: Effect of ILE to LYS ratio on dietary crude protein content:US diets*

References

Ball, R. O. and F. X. Aherne (1982): Effect of diet complexity and feedrestriction on the incidence and severity of diarrhoea in early-weanedpigs. Can. J. Anim. Sci. 62: 907–913.

Ball, R. O. and F. X. Aherne (1987): Influence of dietary nutrientdensity, level of feed intake and weaning age on young pigs. 2. Ap-parent nutrient digestibility and incidence and severity of diarrhoea.Can. J. Anim. Sci. 67: 1105–1115.

Becker, D. E., A. H. Jensen, S. W. Terrill, I. D. Smith, and H. W. Nor-ton (1957): The isoleucine requirement of weanling swine fed twoprotein levels. J. Anim. Sci. 16: 26-34.

Becker, D. E., I. D. Smith, S. W. Terrill, A. H. Jensen, and H. W. Nor-ton (1963): Isoleucine need of swine at two stages of development. J. Anim. Sci. 22: 1093-1096.

Bergstrom, J. R., J. L. Nelssen, M. D. Tokach, and R. D. Goodband(1997): Determining the optimal isoleucine:lysine ratio for the SEW-reared, 10 to 20 kg pig. J. Anim. Sci. 75 (Suppl. 1): 60 (Abstr.).

Block, K. P. (2000): Interactions among leucine, isoleucine, and va-line with special reference to the branched-chain amino acid antago-nism. Page 229-244 in Absorption and Utilization of Amino Acids,Vol. 1. M. Friedman, ed. CRC Press Inc., Boca Raton, FL.

Bravo, F. O., R. J. Meade, W. L. Stockland, and J. W. Nordstrom(1970): Reevaluation of the isoleucine requirement of the growingpig-plasma free isoleucine as a response criterion. J. Anim. Sci. 31:1137-1141.

Brinegar, M. J., J. K. Loosli, L. A. Maynard, and H. H. Williams(1950): The isoleucine requirement for the growth of swine. J. Nutr.42: 619-624.

Brown, H. W., B. G. Harmon and A. H. Jensen (1974): Total sulfur-containing amino acids, isoleucine and tryptophan requirements ofthe finishing pig for maximum nitrogen retention. J. Anim. Sci. 38:59-63.

Chung, T. K., and D. H. Baker (1992): Ideal amino acid pattern for10-kilogram pigs. J. Anim. Sci. 3102-3111.

Danielsen, V. (1984): Effekten av reduseret proteintilldelning tillsmagrise / The effect of reduced protein supply for weaners. Hyolo-giosk Tidskrift 12: 16-19.

Dean, D. W., L. L. Southern and T. D. Bidner (2004): Isoleucine re-quirement of late finishing barrows. Minnesota Nutrition Conference,St. Paul, September 21-22, (in press).

Dean, D. W., L. L. Southern, B. J. Kerr, and T. D. Bidner (2005):Isoleucine requirement of 80 to 120 kilogram barrows fed corn-soy-bean meal or corn-blood cell diets. J. Anim. Sci. 83: 2543-2553.

Body weight (kg)Ingredient (%) 25 – 40 40 – 70 70 – 115Corn 71.52 69.06 68.37

Soybean meal, 48 % 19.80 15.30 11.49

Wheat middlings 4.96 11.95 16.54

Vitamin/Mineral-Premix 3.27 3.22 3.19

L-Lys-HCl 0.31 0.30 0.27

DL-Methionine 0.07 0.08 0.04

L-Threonine 0.07 0.06 0.10

L-Tryptophan – 0.03 –

Nutrients (%)ME (MJ/kg) 13.5 13.2 13.0

(kcal/kg) 3230 3150 3110

Crude Protein 16.5 15.3 14.1

min ratios min ratios min ratios

stand. dig. Lys 0.90 100 0.81 100 0.71 100

stand. dig. Met 0.31 33 0.28 33 0.25 33

stand. dig. M + C 0.54 60 0.50 62 0.46 65

stand. dig.Thr 0.57 63 0.53 65 0.50 70

stand. dig.Trp 0.16 18 0.17 19 0.13 19

stand. dig. Ile 0.56 60 0.49 60 0.44 60

* Basis: US ingredient prices, summer 2005.



Henry, Y. and B. Seve (1991): Incidence de l’équilibre en acides am-inés du régime sur l’appétit et la croissance du porc, selon le taux deprotéines et leur nature: l’exemple du tryptophane. Journées Rech.Porcine en France 23: 119–126.

James, B. W., R. D. Goodband, M. D. Tokach, J. L. Nelssen, J. M.Derouchey, and J. C. Woodworth (2001): The optimum isoleucine:ly-sine ratio to maximize growth performance of the early-weaned pig.J. Anim. Sci. 79 (Suppl. 2): 62 (Abstr.).

Jin, C. F., I. H. Kim, K. Han and S. H. Bae (1998): Effects of supple-mental synthetic amino acids to the low protein diets on the perfor-mance of growing pigs. Asian-Aus. J. Anim. Sci. 11: 1–7.

Kats, L. J., J. L. Nelssen, M. D. Tokach, R. D. Goodband, J. A.Hansen and J. L. Laurin (1994a): The effect of spray-dried porcineplasma on growth performance in the early-weaned pig. J. Anim.Sci. 72: 2075-2081.

Kats, L. J., J. L. Nelssen, M. D. Tokach, R. D. Goodband, T. L. Wee-den, S. S. Dritz, J. A. Hansen and K. G. Friesen (1994b): The effectsof spray-dried blood meal on growth performance in the early-weaned pig. J. Anim. Sci. 72: 2860-2869.

Kendall, D. C., B. J. Kerr, R. W. Fent, S. X. Fu, J. L. Usry and G. L.Allee (2004): Determination of the true ileal digestible isoleucine re-quirement of 90 kg barrows. J. Anim. Sci. 82 (Suppl. 2): 67 (Abstr.).

Kerr, B. J., M . T. Kidd, J. A. Cuaron, K. L. Bryant, T. M. Parr, C. V.Maxwell and E. Weaver (2004a): Utilization of spray-dried bloodcells and crystalline isoleucine in nursery pig diets. J. Anim. Sci. 82:2397-2404.

Kerr, B. J., M. T. Kidd, J. A. Cuaron, K. L. Bryant, T. M. Parr, C. V.Maxwell and J. M. Campbell (2004b): Isoleucine requirements andratios in starting (7 to 11 kg) pigs. J. Anim. Sci. 82: 2333-2342.

Kerr, B. J., T. M. Parr, B. S. Borg, J. M. Campbell, K. L. Bryant, andM. T. Kidd (2002): Development of an isoleucine deficient diet ingrowing and finishing pigs. J. Anim. Sci. 80 (Suppl. 2): 41. (Abstr.).

Langer, S., and M. F. Fuller (2000): Interactions among thebranched-chain amino acids and their effects on methionine utiliza-tion in growing pigs: Effects on nitrogen retention and amino acidutilization. Br. J. Nutr. 83: 43-48.

Le Bellego, L., J. van Milgen, S. Dubois and J. Noblet (2001): Energyutilization of low protein diets in growing pigs. J. Anim. Sci. 79:1259–1271.

Le Bellego, L. and J. Noblet (2002): Performance and utilization ofdietary energy and amino acids in piglets fed low protein diets. Live-stock Production Science, 76: 45-58.

Le Bellego, L., J. Noblet and J. van Milgen (2002): Effect of high tem-perature and low protein diets on performance on growing-finishingpigs. J. Anim. Sci. 80: 691-701.

Lenis, N. P. and J.T.M. van Diepen (1997): Requirement for appar-ent ileal digestible isoleucine of young pigs. J. Anim. Sci. 75 (Suppl.1): 185 (Abstr.).

Liu, H., G. L. Allee, J. J. Berkemeyer, K. J. Touchette, J. D. Spencerand I. B. Kim (1999): Effect of reducing protein level and addingamino acids on growth performance and carcass characteristics of fin-ishing pigs. J. Anim. Sci. 77 (Suppl. 1): 69. (Abstr.).

Liu, H., G. L. Allee, E. P. Berg, K. J. Touchette, J. D. Spencer and J.W. Frank (2000a): Amino acid fortified corn diets for late-finishingbarrows. J. Anim. Sci. 78 (Suppl. 2): 45. (Abstr.).

Liu, H., G. L. Allee, K. J. Touchette, J. W. Frank and J. D. Spencer(2000b): Effect of reducing protein and adding amino acids on per-formance, carcass characteristics and nitrogen excretion, and the va-line requirement of early-weaned finishing barrows. J. Anim. Sci. 78(Suppl. 2): 45. (Abstr.).

Mitchell, J. R., Jr., D. E. Becker, B. G. Harmon, H. W. Norton and A.H. Jensen (1968a): Some amino acid needs of the young pig fed asemisynthetic diet. J. Anim. Sci. 27: 1322-1326.

Mitchell, J. R., Jr., D. E. Becker, A. H. Jensen, B. G. Harmon and H.W. Norton (1968b): Determination of amino acid needs of the youngpig by nitrogen balance and plasma-free amino acids. J. Anim. Sci.27: 1327-1331.

NRC (1998): Nutrition Requirements of Swine. 10th ed. Natl. Acad.Press, Washington, DC.

Oestemer, G. A., L. E. Hanson, and R. J. Meade (1973): Reevaluationof the isoleucine requirement of the young pig. J. Anim. Sci. 36: 679-683.

Owen, K. Q., J. L. Nelssen, R. D. Goodband, M. D. Tokach, L. J. Katsand K. G. Friesen (1995a): Added dietary methionine in starter pigdiets containing spray-dried blood products. J. Anim. Sci. 73: 2647-2654.

Owen, K. Q., R. D. Goodband, J. L. Nelssen, M. D. Tokach and S. S.Dritz (1995b): The effect of dietary methionine and its relationship tolysine on growth performance of the segregated early-weaned pig. J. Anim. Sci. 73: 3666-3672.

Parr, T. M., B. J. Kerr and D. H. Baker (2004): Isoleucine require-ment for late-finishing (87 to 100 kg) pigs. J. Anim. Sci. 82: 1334-1338.

Parr, T., M., B. J. Kerr and D. H. Baker (2003): Isoleucine require-ment of growing (25 to 45 kg) pigs. J. Anim. Sci. 81: 745-752.

Pfeiffer, A., H. Henkel, M. W. A. Verstegen and I. Philipczyk (1995):The influence of protein intake on water balance, flow rate and ap-parent digestibility of nutrients at the distal ileum in growing pigs.Livest. Prod. Sci. 44: 179–187.

Prohaszka, L. and F. Baron (1980): The predisposing role of high di-etary protein supplies in enteropathogenic E. coli infections of weanedpigs. Zentralblatt für Veterinärmedizin 27: 222–232.

Schutte, J. B. and M. Pack (1995): Sulfur amino acid requirement ofbroiler chicks from 14 to 38 days of age. 1. Performance and carcassyield. Poult. Sci. 74: 480-487.

Taylor, S. J., D.J.A. Cole and D. Lewis (1985): Amino acid require-ments of growing pigs. 6. isoleucine. Anim. Prod. 40: 153-160.

Taylor, S. J., D.J.A. Cole and D. Lewis (1984): Amino acid require-ments of growing pigs. 5. The interaction between isoleucine andleucine. Anim. Prod. 38: 257-261.

Wang, T. C., and M. F. Fuller (1989): The optimal dietary amino acidpattern for growing pigs. 1. Experiments by amino acid deletion.Br. J. Nutr. 52: 77-89.

Dr. MeikeRademacheremail: [email protected]



Effect of DL-Methionine on Various Performance and Slaughter

Characteristics in Slowly Growing Broilers Fed According to Organic

Farming Recommendations

A. Lemme, K. Damme, and A. Petri

Research Highlights

501020

The EU directive 1804/99 sets therules for organic livestock produc-tion. Feeding broilers in organicfarming systems is also regulated bythis directive. In this context espe-cially those paragraphs are impor-tant where the guidelines for dietcomposition, allowed ingredients,feed additives etc. are given. Onlythe use of feedstuffs listed in AnnexII, Parts C and D are authorised,which have to be produced accord-ing to organic farming rules, but un-til 24. August 2005 and inclusion ofmaximum 20 % of conventionallyproduced ingredients such as maizegluten, or potato protein is possible.After this transitional period it willbe much more, difficult to cover thenutrient needs of poultry, since sup-plementation of diet with crystallineamino acids are generally prohibited.

Especially the lack of native methio-nine in leguminoses and sunflowermeal, the common organic proteinsources, limits growth developmentof broilers, impairs utilisation of thedietary protein and increases nitro-gen excretion.

Although maximising broiler perfor-mance is not the prime target in theorganic farming systems, questionarises whether the guidelines of theEU directive 1804/99 are in line withthe idea of sustainability in broilerproduction. Another problem is thedifficulty to harmonise productionstandards at EU level. There are ma-jor differences in the interpretationand implementation of the EU Regu-lation (Bloch, 2003). Austrian Min-istry for example supports the ban ofsynthetic amino acids (SAA), whilst

the Dutch Ministry for Agriculture,the France and Belgian producersand feed compounders favour thereintroduction of SAA. In the UK,authorities tolerate the use of SAAin organic poultry rations in the moment.

Therefore, the objective of the experiment presented here was toinvestigate the effects of three kindsof diets on performance, feed andprotein conversion as well as relatedparameters under organic farmingconditions. Diets were formulated tocurrently valid regulations and tothat regulation coming in force inAugust 2005 with and without sup-plementation of DL-Met.

Archiv für Geflügelkunde 2005, 69, 4,159-166



Dietary Trypotphan Need of Broiler Males from Forty-Two to Fifty-Six

Days of Age

A. Corzo, E.T. Moran, D. Hoehler, and A. Lemme

Research Highlights

Tryptophan requirements of broilermales from 42 to 56 d of age werestudied. Ross x Ross 308 chicks wereplaced in an open-sided house, andprovided common starter and grow-er diets from 0 to 42 d of age. Subse-quently, a corn, soybean meal, corngluten meal, and gelatin combina-tion of feedstuffs provided 0.12 %Trp to which 0.04 % increments of

L-Trp were supplemented at the ex-pense of an isonitrogenous amountof L-Glu to 0.24 %. Birds that re-ceived diets containing 0.12 % Trpexhibited aberrant behavior basedon the spillage of considerable

amounts of feed from the troughand contamination of adjacent waterers with floor litter. There werereductions in body weight gain, feedconversion, and carcass and breastfillets weights and yields with dietaryTrp at 0.12 %, but these were not affected at Trp levels at or above0.16 %. Exponential regessionanalyses showed that body weightgain improved as Trp increased, withmaximum overall performance be-ing attained at 0.17 %, wheraschilled carcass weight maximized at0.16 % dietary Trp. Nitrogen reten-tion measured using the same exper-

imental feeds and sample birds at 48to 49 d of age was unaffected by di-etary Trp. Plasma uric acid, albumin,total protein, and aspartate-trans-ferase measured concurrently withnitrogen retention were not altered;however, blood glucose was reducedin broilers fed 0.12 % dietary Trp.Overall results suggest that broilermales need approximately 0.17 %dietary Trp between 42 and 56 d ofage, which closely agrees with theNRC (1994) recommendation of0.16 % Trp estimated from modelingfor this feeding period. Poultry Science 2005, 84, 226-231

501020



Effect of Glutamine and Spray-Dried Plasma on Growth Performance,

Small Intestinal Morphology, and Immune Responses of Escherichia coli

K 88+-challenged weaned pigs

G. F.Yi, J. A. Carroll, G. Allee, A. M. Gaines, D. C. Kendall, J. L. Usry,Y.Torides, and S. Izuru

Research Highlights

501020

Forty weaned barrows (5.32 ± 0.3 kgBW) at 17 ± 2 d of age were used toinvestigate the effects of feeding glu-tamine and spray-dried plasma onthe growth performance, small in-testinal morphology, and immuneresponses of Escherichia coli K88+-challenged pigs. Pigs were allotted tofour treatments including: 1) non-challenged control (NONC); 2) chal-lenged control (CHAC); 3) 7 % (as-fed basis) spray-dried plasma (SDP);and 4) 2 % (as-fed basis) glutamine(GLN). On d 11 after weaning, allpigs were fitted with an indwellingjugular catheter. On d 12 afterweaning, pigs in the CHAC, SDP,and GLN groups were orally chal-lenged with skim milk E. coli K88+

culture, whereas pigs in the NONCgroup were orally inoculated withsterilized skim milk. Rectal tempera-tures and fecal diarrheic scores wererecorded and blood samples collect-ed at 0 (baseline), 6, 12, 24, 36, and

48 h after the challenge for serumhormone and cytokine measure-ments. At 48 h postchallenge, allpigs were killed for evaluation ofsmall intestinal morphology. Therewas no effect of feeding SDP or GLNon growth performance during the11-d prechallenge period (p = 0.13).At 48 h after the challenge, CHACpigs had decreased ADG (p = 0.08)and G:F (p = 0.07) compared withthe NONC pigs; however, SDP andNONC pigs did not differ in G:F, andGLN and NONC pigs did not differfor ADG and G:F. At 6, 36, and 48 hafter the challenge, CHAC, SDP, andGLN pigs had increased rectal tem-perature relative to the baseline (p = 0.09). At 12 and 36 h after thechallenge, CHAC pigs had the high-est incidence of diarrhea amongtreatments (p = 0.08). Serum IL-6and ACTH were not affected bytreatment or time after E. coli chal-lenge (p = 0.11). In proximal, midje-

junum, and ileum, CHAC pigs hadgreater villous atrophy and intestinalmorphology disruption than NONCpigs (p <0.01), wheras SDP and GLNpigs hd mitigated villous atrophy andintestinal morphology impairmentafter E. coli challenge. Pigs in theSDP had the lowest GH at 12 h andthe greatest GH at 36 h after thechallenge among treatments (p =0.08). Pigs in the NONC had thehighest IGF-1 at 12 and 36 hpostchallenge (p < 0.04). These re-sults indicate that feeding glutaminehas beneficial effects in alleviatinggrowth depression of E. coli K88+-challenged pigs, mainly via main-taining intestinal morphology andfunction, and/or possibly via modu-lating the somatotrophic axis.

Journal Animal Science, 2005, 83, 634-643


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