Department of Animal Science North Carolina State University Understanding and Applying Nutrition Concepts to Reduce Nutrient Excretion in Swine.

Department of Animal Science

North Carolina State University

Understanding and Applying Nutrition Concepts to Reduce Nutrient Excretion

in Swine

Outline

• Introduction

• General strategies to reduce nutrient excretion

• Methods to reduce Nitrogen excretion

• Methods to reduce Phosphorus excretion

• Reducing Micro-mineral excretion

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Balance between animal production and crop production

• Animal production has developed into an intensive industry– production facilities are large and clustered together

– feedstuffs are shipped in from crop-producing regions

• Animal waste not used as a fertilizer– too expensive to ship to crop-producing regions

• Alternative methods to deal with waste where found:– Store and treat (eliminates N and C) in lagoons

– Apply to crop land based on N (which may over-apply P)

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• Nutrients in manure should be utilized– process to yield usable products

– applied to crop land such that a balance is maintained

0

5

10

15

20

25

30

Phosphor Copper Zinc

pig

s/a

cre

Jongbloed & Lenis, 1993

us

Manure nutrient utilizationNC STATE UNIVERSITY

Amounts of N output for different classes of swine, calculated for a 100 sow equivalent (89 productive sows)

Nitrogen OutputClass Per Pig

(g/d)Per Space(kg/year)

% of total N output/N Intake

SowsReplacement GiltsWeaned SowsGestationLactation

51424079

186103954459

1.70.98.74.2

69737757

PigletsSuckling (27 d)Post-weaning (to 55 lbs)

111

54907

0.58.2

1447

Growing-Finishing Pigs55 to 230 lbs 38 8,360 75.8 67

Total 11,023 100 65Adapted from Dourmad et al. (1992)

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Digestion and retention of N, P, Cu and Zn by different classes of swine

Mineral Nursery Finishing Gestating LactatingNitrogen

Digestion, %Retained, %

75 to 8840 to 50

75 to 8830 to 50

8835 to 45

--20 to 40

PhosphorusDigested, %Retained, %

20 to 7020 to 60

20 to 5020 to 45

30 to 4520 to 45

10 to 3510 to 30

ZincDigested, % 20 to 45 10 to 20 -- --

CopperDigested, % 18 to 25 10 to 20

Adapted from Kornegay and Harper (1997)

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Efficiency of nutrient utilization and waste

• Nitrogen retention is only 30%

Indigestible

Endogenous loss

Endogenous catabolism

Mismatch

Accretion

Obligatory catabolism

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General Nutritional Strategies to Reduce Nutrient Excretion

• Feed Efficiency

Improving feed efficiency by 0.1 points ==> 3.3% reduction in nutrient excretion

• Pelleting

Dry matter and N excretion decreased by 23 and 22%

Feed efficiency was improved by 6.6%

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General Nutritional Strategies to Reduce Nutrient Excretion (continued)

• Feed Wastage

Reduction in feed wastage of 2% ==>

reduction in N and P in manure by approximately 3%

• Matching Nutrient Requirements

Multi-phase feeding reduced urinary N excretion by 15% Ammonia emission was reduced by 17%

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Nutrient requirements and phase feeding

0.6

0.7

0.8

0.9

1

1.1

1.2

20 30 40 50 60 70 80 90 100

Body Weight

% L

ysin

e

2-Phase feeding program

6-phase feeding program

Lysine Requirement

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Phase-feeding in Pig Production

1 Feed 2 Feeds

Grow-Fin Grower Finisher Whole Period

Protein Content 16 16.5 14Feed Conversion 3.0 2.5 3.3Feed Intake/Period (kg)

210 75 132 207

N-intake (kg) 5.38 1.98 2.95 4.93N-excretion (kg) 3.48 1.16 1.86 3.02N-excretion (% ofintake)

65 58 63 61

N-retention (kg) 1.90 0.82 1.09 1.91Adapted from Koch (1990)

- 13%

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Savings in feed costs with phase feeding

Number of Phases Diet Cost/Pig Savings over 2-phase program

Increase in Savingsper Additional Diet

2 $42.55 -- --3 $41.41 $1.14 $1.144 $41.01 $1.54 $0.405 $40.67 $1.88 $0.346 $40.43 $2.12 $0.249 $40.10 $2.45 $0.11

12 $39.90 $2.65 $0.06From Pork 98; Source: Dean Koehler, Agri-Nutrition Services, Shakopee, Minn.

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General Nutritional Strategies to Reduce Nutrient Excretion (continued)

Sow diets Finisher dietsMineral Requirement Range Median Requirement Range MedianCalcium, % 0.75 0.62-2.01 1.21 0.50 0.57-1.38 0.96Phosphorus, % 0.60 0.45-1.17 0.84 0.40 0.45-0.78 0.62Copper, ppm 5 12-222 22 3 9-281 20Zinc, ppm 50 79-497 167 50 103-205 149

Adapted from Spears (1996)The median value indicates that 50% of the samples were below and 50% of the samples were above thisvalue.

Concentrations of selected minerals in sow and grower-finisher feeds

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Methods to Reduce N excretion and Ammonia Emission

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Nitrogen flow in swine

N Intake, 100%

Digestible N, 85%

Available N, 80%

Retained N, 35%

Fecal N, 15%

Urinary N, 50%

Ammonia, 20%

Manure, 45%

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Metabolism CratesNC STATE UNIVERSITY

Feeds are not digested completely: indigestible fraction contributes to waste

Protein ‘Undigested N’ Fecal N

Amino acids

Digestion

Protein

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Improving digestibility of feed 1% decreases waste 1.4%

The digestibility of feeds can be improved through:

• technological treatments (pelleting, extrusion, etc,)

• Enzymes– Xylanases and beta-glucanases - degrade non-starch

polysaccharides (NSP)

– Improve digestibility of nitrogen 2-3% in typical diets

– Proteases, (hemi) cellulases are being developed

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Protein ‘Undigested N’ Fecal N

Amino acids

Endogenousexcretion

Digestion

Digestion of feed causes the animal to loose nitrogen directly through endogenous losses

Protein

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25% of the endogenous secretions end up as waste

• Animal secretes enzymes/protein during the digestive process– only 75% reabsorbed

– Loss is accounted for in ileal digestibility tables

Apparent Real Endogenous NLoss

Skim Milk 84.4 92.7 8.3

Fish meal 73.0 89.3 16.3

Soybeanmeal

76.5 90.6 14.1

Schulze, 1994

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Protein ‘Undigested N’ Fecal N

Amino acids

Endogenousexcretion NH3

Digestion

inefficiency

Feed induced loss of NLosses (catabolism) associated with the synthesis of

endogenous secretions

Protein

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30% of the amino acids targeted for endogenous secretions are catabolized

• For the synthesis of these endogenous secretions, some amino acids are catabolized (losses due to inefficiencies)

• Feedstuffs can influence endogenous secretions, and thus endogenous losses and endogenous-linked catabolism– neutral detergent fiber increases endogenous losses

without affecting secretion or catabolism

– trypsin inhibitors increases endogenous secretions, thus catabolism as well as secretion

• Digestibility tables do not account for these losses!

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Protein ‘Undigested N’ Fecal N

Amino acids

Endogenousexcretion NH3

Digestion

energy

inefficiency

Amino acids which can not be utilized for protein synthesis are catabolized

Protein

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A large proportion of nitrogen is wasted because feeds are not idealy balanced,

• Feed composition determined through least-cost formulation:– diet of minimal cost to meet nutritional needs

• Pigs require amino acids, not protein

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Ileal true digestible amino acid patterns for pigs in three different weight classes

Ideal Pattern, % of lysineAmino Acid 10 to 45 lbs 45 to 110 lbs 110 to 240 lbsLysine 100 100 100Threonine 65 67 70Tryptophan 17 18 19Methionine + Cystine 60 62 65Isoleucine 60 60 60Valine 68 68 68Leucine 100 100 100Phenylalanine + Tyrosine 95 95 95Arginine 42 36 30Histidine 32 32 32

Adapted from Baker (1996)

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Balance trial for pigs fed a corn-soybean meal-dried whey (C-SBM-DW) diet or a purified amino acid diet

DietItem C-SBM-DW Amino AcidDaily Gain, g/d 505 511Daily Feed Intake, g/d 791 824Gain-Feed Ratio 623 620Nitrogen

Intake, g/dDigestible, g/dRetained, g/dDigestible, % of intakeRetained, % of intake

18.215.510.285.156.0

14.213.69.7

96.168.3

Adapted from Chung and Baker (1991)

N Excretion was reduced by 28%

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Effect of low protein diets on N excretion and ammonia emission

Grower and Finisher Protein Level, %Item 17.8% and 15.4%, resp. 16.2% and 13.5%, resp.N Intake, lbs 2.43 2.17N Retention, lbs 0.79 0.79N excretion

Total excretion, lbsN in manure, lbsN in air, lbs

1.641.200.44

1.381.000.38

Adapted from Latimier, 1993The grower and finisher periods covered the weight ranges of 68 to 139 lbs and 139 to 223 lbs,respectively.

N Excretion was reduced by 9% for each 1% reduction in CPN in the air was reduced by 8% for each 1% reduction in CP

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0

1

2

3

4

5

6

7

16 15.5 15 14.5 14 13.5 13CP (%)

118

120

122

124

126

128

130

132

134

136

138

Added Lysine, lbs/ton Cost, $/ton

Cost or value of reducing CP in a corn-soybeanmeal based diet

Corn $90, SBM $180, Lysine-HCl $2400, Methionine $2700,Threonine $2.63/lb, Tryptophan $15.80/lb

Lys

ine,

lbs/

ton C

ost/ton

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Ammonia is mainly derived from N excreted in urine: capturing some of the N in feces reduces ammonia emission

Protein ‘Undigested N’ Fecal N

Amino acids

Endogenousexcretion Urea Urinary ureaNH3

Digestion fermentation

Protein

energy

inefficiency

inefficiency

85% of ammonia is derived from urea (Voermans, 1994)

NH3 (l)

NH4+

NH3 (g)

urease

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Fiber reduces urinary N, thus ammonia emission

• Nitrogen excretion can be shifted from urine to feces– supply non-starch polysaccharides (NSP) in diet

• source of energy for microbes in large intestines– stimulates growth of microbes, and thus nitrogen accretion

• Increasing NSP intake with 100 g/day:– decreases ammonia emission 5%

(partially due to a decrease in manure pH)

• Caution: – NSP decrease nitrogen digestion– NSP might well increase odor emission

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Swine Malodor Emission Laboratory

Odor Chamber FTIR EquipmentChamber, Inside

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Methods to Reduce P Excretion

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Functions of Phosphorus

• 80 to 85% of P is found in bone

• Non-skeletal P is concentrated in Red Blood Cells, Muscle, and Nerve Tissue

• Present in Phosphoproteins, Nucleoproteins, Phospholipids, Phosphocreatine and ATP– Membrane Structure

– Energy Metabolism

– Buffer System

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Reducing Phosphorus Excretion Through Nutrition

• Feed to meet the Pigs Requirement– Reduce excess levels in feed

– Feed multiple phases

• Use available P levels rather than total– Ingredient values

– Pig requirement

• Use of phytase or low phytic acid ingredients

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Available P levels in diets formulated to contain 0.5% total P

Diet Added Dical. P, % Total P, % Available P, %Corn-Soybean Meal 0.96 0.50 0.23Wheat-Soybean Meal 0.57 0.50 0.28Corn-Canola Meal 0.09 0.50 0.10Corn-Soybean Meal-Wheat Midds 0.68 0.50 0.20

Growing Pig Requirement (NRC) 0.50 0.23Adapted from Cromwell (1990).

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Enzymes have many environmental benefitsPhytase

• Phytate is an indigestible form of phosphorus– corn: 90% of phosphorus bound in phytate

– soybean meal: 75% of phosphorus bound in phytate

• Phytase– improves digestibility of phytate

• reduces phosphorus excretion 32%

• improves nitrogen digestibility 2%

– routinely used in Europe

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Estimated cost of phytase supplementation using least cost diet formulation

Level of Phytase Added Dicalcium phosphate removed(lbs/ton)

Diet cost above a standardcorn-soybean meal diet

500 U per kg 10.9 $1.23250 U per kg* 10.9 $0.14

* 250 U of phytase/kg of diet is below the recommended level and may not liberate enough P to maintain pigperformance

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Low Phytate Corn

0.5

0.7

0.9

1.1

1.3

1.5

1.7

1.9

Normal Low Phytate

ADG, lbs

0.59

0.50

0.42

0.33

Available P: 0.35 0.26 0.18 0.09 0.45 0.37 0.28 0.20

Availability of P was set at 20% for corn and 75% for low phytate corn

Total P

Cromwell, 1999

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Low Phytate Corn and Phytase

0

1

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3

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7

8

Normal Low Phytate

P Excretion, g/d

Control+ Phytase

Total P: 0.55 0.45 0.45 0.35Reduction in P Excretion: -- 23% 35% 51%

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Reducing the Excretion ofMicro-Minerals

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Excretion of zinc and copper by different classes of swine*

Zinc Copper

PhaseDiet, ppm Excretion

(g/d)Diet, ppm Excretion

(g/d)Nursery

PrestarterStarter

2,000125

0.650.08

240240

0.0840.186

Grower-Finisher

125 0.23 15 0.027

SowsGestationLactation

125125

0.200.54

1515

0.0240.065

* Calculations are on a per day basis

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Effect of Reducing Zn and Cu in pig diets on Zn and Cu excretion in waste

MineralHigh InorganicNursery/Sow

High InorganicFinishing

ReducedInorganic (all

phases)Copper 25 15 5

Zinc 150 100 25

Iron 180 100 25

Manganese 60 40 10

From Creech et al. (1998)

Treatments

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Growth Performance of Nursery and Growing-Finishing Pigs Fed Reduced Levels of Trace-Minerals

High Inorganic Reduced Inorganic

NurseryGain, lbs/dayIntake, lbs/dayGain/Feed

0.991.880.53

0.971.840.53

Grower-FinisherGain, lbs/dayIntake, lbs/dayGain/Feed

1.785.090.35

1.805.030.36

Adapted from Creech et al. (1998)

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Effect of Reducing Trace-Mineral Levels on Mineral Excretion

HighInorganic

ReducedInorganic

% Change

Growing PhaseZinc, ppmCopper, ppm

940168

461113

- 51- 33

Finishing PhaseZinc, ppmCopper, ppm

991176

53193

- 46- 47

Adapted from Creech et al. (1998)

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Bottom line• Phase Feeding ===> 15 %

• Reducing N– Lowering CP (1.5%) ===> 13.6 %

– Adding lysine + methionine ==> 22.1 %

– Adding other AA + feedstuffs => 30.6 %

• Reducing P– Lower Requirement ===> 15.7 %

– Adding Phytase ===> 26.5 %

– Phytase + feedstuffs ===> 41.0 %

• Reducing Zn and Cu– Lower dietary levels ===> 30 - 50%

• But; many of these reductions in waste can only be achieved if a higher production cost is acceptable

Jongbloed and Lenis, 1992

Creech, 1998

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