AVS 474 Beef Cattle Science - University of Idaho Materials/Forages 2018 (GEC... · Forage is baled vs. ensiled? ii. Small vs. large acreage to harvest? iii. Rain early vs. late in

Gwinyai E. Chibisa, Ph.D.

FORAGES

http://craig-stephen.photoshelter.com/image/I0000yWGWHAEnwSI

What is Forage?

Characteristics

i. Bulky

Implications on animal nutrition?

ii. High fiber

Is fiber important?

iii. Lower digestibility than grains

High quality (60 – 68%) E.g., ?

Medium quality (53 – 59%) E.g., ?

Low quality (<53%) E.g., ?

What is Forage Quality?

“The extent to which a forage has the

potential to produce a desired animal

response”

Key responses?

i. ?

ii. ?

iii. ?

Forage Quality is “Milk in the Bucket”

Ball et al, 2001. American Farm Bureau Federation Publication 1-01

Forage Quality is “Calves on the Ground”


Forage Quality is “Pounds on The Scale”


Forage Quality

Factors that affect animal responses?

i. Nutrient composition?

ii. Palatability?

iii. Intake?

iv. Digestibility?

v. Anti-quality factors?

Forage Quality (cont.)

Nutrient composition

i. Crude protein

ii. Carbohydrates

Fiber/NDF (cellulose, hemicellulose, lignin)

ADF (cellulose, lignin)

Non-structural CHO (starch, sugar)

iii. Other nutrients?

Plant Cells

NDF?

ADF?

Forage Nutrient Composition


Forage Fiber & Nutritive Value


Forage Fiber (NDF & ADF) Determination

What Happens to NDF in the Rumen?

Gaylean and Owens, 1988. Proc. Of the Southwest Nutrition & Management Conference

Dietary NDF and DMI (and pH)

pH

DMI

Zebeli et al., 2012. JDS. 95:1041-1056

Estimating DMI (as % of BW)

DMI (% of BW) = 120 ÷ %NDF

Forage Quality NDF, % DMI, % of BW

Excellent 38 3.16

42 2.86

46 2.61

50 2.40

Poor 54 2.22

ADF and Digestibility

Undersander, 2003. http://www.uwex.edu/ces/forage/

http://www.uwex.edu/ces/forage/

Estimating % Digestible DM

% Digestible DM = 88.9 – (ADF% × 0.779)

ADF, % DDM, %

30 65

35 61

40 58

45 54

50 50

Effects of ADF and NDF on Hay Price

Putnam et al., 2008. Irrigated Alfalfa Management in Mediterranean & Desert Zones

Forage Quality (cont.)

Factors that influence forage quality?

i. Maturity stage

Leaf-to-stem ratio

ii. Species differences

Grasses vs. Legumes

Cool-season vs. Warm-season

iii. Variety differences

iv. Growth conditions

v. Harvesting & Storage conditions

i. Maturity, Yield & Quality

http://www.gov.mb.ca/agriculture/crops/production/forages/print,annual-crops-an-excellent-way-to-increase-your-feeding-flexibility.html

Maturity Stage

lignin

Lignification and Digestibility

Lignin (% of NDF) Jung, 2012. Proceedings: Florida Ruminant Nutrition Symposium

Examples of Changes in Forage Quality with Maturity

U.S.-Canadian tables of feed composition, third edition. 1982.

ii. Grasses vs. Legumes

Grasses Legumes

Crude protein

Cell wall/fiber

Lignin

Energy

Minerals (E.g., Ca & Mg)

Bloat

ii. Grasses vs. Legumes (cont.)


Grasses

Non-leguminous, require less management

Cool-season vs. warm-season

Keyser, 2012. UT Ext. Pub. SP731-A

Cool vs. Warm-Season Grasses

Navarrete-Tindall. 2010. Missouri Prairie Journal. 31:20-25

Cool Season Grasses

i. Orchardgrass

ii. Bromegrass

iii. Tall Fescue

iv. Ryegrass

v. Bluegrass

vi. Wheatgrass

vii. Red Canarygrass

viii. Timothy, etc.

Cool Season: Orchardgrass

https://gobotany.newenglandwild.org/species/bromus/inermis/?pile=poaceae

Cool Season: Orchardgrass (cont.)

Shade tolerant perennial

Much of PNW irrigated pasture

Highly productive

Highly palatable

Compatible with alfalfa/clover mixes

Marginal winter hardiness

Cool Season: Smooth brome


Cool Season: Smooth brome (cont.)

Shade tolerant, Winter hardy

Highly productive, Slow regrowth

Very palatable

High protein content

Erosion control e.g., “Lincoln”

Cool Season: Downy brome


Cool Season: Downy brome

“Cheatgrass” (Annual weed)

Drought and grazing tolerant

A lot of negatives

Outcompetes most grasses (domination)

Quick decrease in quality (maturity)

Fire prone!

Cool Season: Tall Fescue

http://www.pggwrightsonseeds.com.au/products/grasses/tallfescue/resolute/; http://www.biopix.com/trifid-bur-marigold-bidens-tripartita_photo-.aspx

Cool Season: Tall Fescue

Adapted to wide range of soil types

Highly productive

Negatives

Summer slump

Fescue toxicity (endophyte fungus)

Some varieties e.g., Alta (vs. Johnstone, Fawn)

Endophyte fungus

Produces ergot alkaloids

Ergovaline

Lysergic acid

http://stablemanagement.com/article/endophyteinfected-fescue-problems-nonpregnant-horses-14616; http://journal.frontiersin.org/article/10.3389/fchem.2014.00110/full

Ergot Alkaloids

Numerous negative effects e.g., compromised

neurological function, embryonic loss

Ergot alkaloids e.g., Lysergic acid

Biogenic amines e.g., Serotonin & Dopamine

Losses of up to US$2 Billion/year

Tall Fescue Toxicity

Kallenbach, 2015. J. Anim. Sci. 93:5487-5495

Tall Fescue Toxicity

Kallenbach, 2015. J. Anim. Sci. 93:5487-5495

“Fescue foot”, heat stress

Tall Fescue Toxicity (cont.)

http://thestockexchangenews.com/vet-talk-ergot-poisoning-in-cattle/; http://blog.nature.org/science/2014/02/03/bison-good-cattle-bad-a-prairie-ecologists-perspective/cows-in-pond/

Cool Season Grasses

Refer to “Improved grasses and legumes for

Idaho” for information on the following:

iv. Ryegrass

v. Bluegrass

vi. Wheatgrass

vii. Red Canarygrass

viii. Timothy

Warm Season Grasses

i. Bermudagrass

ii. Bahia

iii. Switchgrass

iv. Bluestem

v. Bluegrass

vi. Indiangrass, etc.

Warm Season Annuals

i. Sorghum

ii. Sudan grass

iii. Sorghum × Sudan hybrids

High alkaline soil tolerant

Drought tolerant

Very productive

Prussic acid & nitrate poisoning?http://www.cattletoday.com/forum/viewtopic.php?f=14&t=99322/

Prussic Acid Poisoning

Plant HCN content influenced by:

Stage of growth, Drought, Frost, etc.

HCN + Hemoglobin Cyanoglobin

(Hydrogen cyanide/Prussic Acid)

(Cyanogenic glucoside)

http://homepage.ruhr-uni-bochum.de/Markus.Piotrowski/Index.html?Research_Nitrilase.html

Nitrate Toxicity

Plant nitrate content influenced by:

Drought & high T˚C, Lack of sunlight, disease etc.

http://www.agweb.com/article/get-to-know-nitrate-toxicity-naa-wyatt-bechtel/

Warm Season Annuals

iv. Small cereals (Barley,

Rye, Wheat, Oats…)

Use with annual legume (e.g.,

Spring pea) for good silage

Aim for grain development

(late milk-early dough)http://www.progenellc.com/images/imagepage/oats/oats.html

Summary - Grasses

i. Many different species

ii. Good source of nutrients

Mix with legumes

iii. Potential anti-quality factors

E.g., Ergot alkaloids, Prussic acid, etc.

Legumes

i. Alfalfa

ii. Birdsfoot Trefoil

iii. Red Clover

iv. White Clover

v. Sainfoin

vi. Annual legumes e.g., beans, peas

Legumes (cont.)

Fixation of atmospheric N

Positives Negatives

1. High CP 1. Low fiber, high lignin

2. High Ca and Mg 2. Induce bloat

3. High vitamin A 3. Phytoestrogens

4. High yield

3 to 4 cuttings

Alfalfa “Queen of Forages”

http://corlandseeds.ca/Deep%2003.JPG; http://portaldelinterior.com/wp-content/uploads/2013/05/recomendaciones-para-el-cultivo-de-alfalfa-Fuente-Wikipedia.jpg

Alfalfa “Queen of Forages” (cont.)

Highly productive

Idaho = 3.9 tons/acre, 4.3 M tons, $871 M (2014)

Good perennial

5 to 6 year stands

Drought resistant

Very nutritious

Structural Components of Alfalfa


Alfalfa “Queen of Forages” (cont.)

Needs well-drained soils

“Heaving”

Winterkill

Low tolerance to overgrazing

Low NSC relative to soluble CP

Bloat problems

Bloat

Accumulation of gasses

“Bloat guard”- Poloxalene

https://quizlet.com/75133666/bovine-gi-rumen-flash-cards/; http://lvspa.org/inc/index.php/more-info/k2-tags/item/74-bloat

Gas

Birdsfoot Trefoil

http://www.extension.umn.edu/garden/diagnose/weed/broadleaf/creeping/birdsfoottrefoil.html;

Birdsfoot Trefoil (cont.)

Tolerant to adverse soil conditions

Acidic, poor drainage, heavy, low native fertility

Exceptional pasture legume

Withstand grazing

Works well with grass e.g., brome & tall fescue

Does not cause bloat (condensed tannins)

E.g., ‘Empire’, ‘Viking’

Legumes

i. Alfalfa

ii. Birdsfoot Trefoil

iii. Red Clover

iv. White Clover

v. Sainfoin

vi. Annual legumes e.g., beans, peas

Red Clover

http://www.donwiss.com/pictures/F-2011-05-22/0073.jpg

Red Clover (cont.)

Require well drained soil (pH > 5.5)

Short-lived perennial

Suited for hay or silage

2 or 3 hay crops

Production of phytoestrogens

Phytoestrogens

E.g, Isoflavones (Formononetin)

Plant content varies

Genetics

Use of low-phytoestrogen varieties

Environmental conditions

E.g., fertilizer deficiency

Phytoestrogens (cont.)

Mimic estradiol

“Clover disease”

Low lambing rates, uterine prolapse, dystocia, death

Temporary or permanent infertility (‘defeminization’)

Estradiol Isoflavone, e.g., Formononetin

White Clover

http://www.gardeningknowhow.com/wp-content/uploads/2007/05/white-clover-lawn.jpg

White Clover (cont.)

Good pasture legume

Highly palatable, nutritious

Commonly planted with grasses

E.g., ‘Ladino’, ‘New York’ (Idaho-adapted)

Mix with Orchardgrass, Tall Fescue

Sainfoin

http://www.wildbeeinternational.com/wbi/wp-content/uploads/2014/03/2013-07-04-14.12.33.jpg

E.g., ‘Shoshone’

Sainfoin (cont.)

Highly palatable

Highly nutritive

Contain phenolics e.g., condensed tannins

Improve protein utilization

Non-bloating nature

Anthelmintic properties (reduce parasites e.g., nematodes)

Can be incorporated into alfalfa pasture

Annual Legumes

E.g., Beans (Faba’s), Peas

Cool-season

Good as silage or for grazing

http://bayoulog.com/2014/10/01/cool-season-wildlife-food-plots/

Summary - Legumes

i. High quality forage

Opportunity to mix with grasses

ii. Reduce the cost of N fertilization

iii. Potential issues

Bloat, Phytoestrogens

Forage Preservation

http://hdwyn.com/hay_bales_agriculture_summer_hd-wallpaper-4733/

Forage Preservation

Why do we preserve forages?

i. ?

ii. ?

iii. ?

Forage Preservation (cont.)

What are the common preservation methods?

i. ?

ii. ?

iii. ?


What are the factors to consider?

i. ?

ii. ?

iii. ?


Is forage preservation a perfect process?

Fresh Vegetation Preserved Forage

DM LossesQuality Loss

Dry Matter Loss

Losses due to:

i. Plant metabolism

ii. Microbial metabolism

iii. Physical processes

Hay

What is hay?

Haymaking

Objectives

i. Produce a high yielding, high quality crop

ii. Rapid curing

iii. Minimize leaf loss

iv. Minimize cell respiration

v. Avoid leaching losses & molding

vi. Maintain quality in storage

Haymaking

Objectives

i. Produce a high yielding, high quality crop

ii. Rapid curing

iii. Minimize leaf loss

iv. Minimize cell respiration

v. Avoid leaching losses & molding

vi. Maintain quality in storage

Haymaking

Phases

Harvesting/Cutting

Curing

Raking

Baling

Storage

Harvesting

http://www.deere.co.za/en_ZA/products/equipment/hay_and_forage_equipment/mower_conditioners/mower_conditioners.page?

When to Harvest?

Impact of plant maturity on DMI & digestibility


When to Harvest?

Forage Species Time of Harvest

Alfalfa Bud stage (1st cutting); 1/10 bloom for 2nd and later cuts

Orchardgrass, Tall Fescue Boot to early head (1st cut);every 4-6 weeks after

Red Clover Early to ½ bloom.

Barley, Oats, Rye, Wheat Boot to early head stage.

Sudan-sorghum hybrids Early boot stage.

Weather conditions?

Curing

What is the objective of curing?

?

Curing (cont.)

Factors that affect the duration of curing

Initial DM%

Environmental

i. Temperature

ii. Humidity

iii. Wind speed

iv. Solar radiation

Conditioning

How Does Rain Affect Hay Quality

i. Leaching (soluble CHO, CP, minerals)

ii. Increased and prolonged respiration

iii. Leaf shattering

iv. Microbial activity

v. Color bleaching

“Make Hay While The Sun Shines”


What Would You Do?

If forage is ready to harvest for hay,

but rain is in the forecast?

Risk Assessment

If you were to go ahead, which of the following

has the higher risk?

i. Forage is baled vs. ensiled?

ii. Small vs. large acreage to harvest?

iii. Rain early vs. late in drying period?

iv. Forecasted rain is “full-frontal” vs. “scattered”?

v. Grass vs. Grass-legume mix vs. legume?

vi. Market for damaged hay, drying agents, etc…

Curing (cont.)

Factors that affect the duration of curing

Initial DM%

Environmental

i. Temperature

ii. Humidity

iii. Wind speed

iv. Solar radiation

Conditioning

Conditioning

Treatment of hay crop to accelerate the

drying process.

Mechanical and/or

Chemical conditioning

Mechanical Conditioning

Conditioners bruise, lacerate, crush or crimp

plant to reduce differential drying of leaves vs.

stems

https://www.poettinger.at/img/landtechnik/scheibenmaeher/rc_aufbereiter_th.jpg

Chemical Conditioning

Desiccants/drying

agents

E.g.,

K2CO3,

NaCO3

http://extension.psu.edu/plants/crops/forages/hay-and-silage/harvest-management/chemical-conditioners-for-hay

Reducing Drying Time

http://www.farmingmagazine.com/dairy/forages/haymaking-101-mowing-tedding-and-raking/

Tedding

Reducing Drying Time

http://www.schinckelhayrakes.com.au/schinckel_inline_rakes.htm

Raking

Baling

https://www.deere.com/en_US/products/equipment/hay_and_forage_equipment/balers/9_series_round_balers/9_series_round_balers.page

Has to be done at the correct moisture

______% moisture?

Consequences of baling when too wet or dry?

DM Losses During Haymaking


DM Losses During Haymaking (cont.)

Process % DM

Respiration 2 - 16

Conditioning (crimper) 1 - 4

Raking at 40-50% moisture 2 - 5

Raking at 10-15% moisture 25 - 30

Baling (rectangular) 2 - 5

Baling (large, round) 15 - 40

Baling When Too Wet

Growth of spoilage microbes (aerobic)

Spoilage bacteria, e.g., bacilli

Yeasts, molds, fungi

Hay (plant sugars, protein) + O2 CO2 + H2O + Heat

Effect of Feeding Moldy Hay in Cattle

Parameter Good Hay Moldy Hay

Hay intake, kg 7.1 6.5

Rumen fermentation characteristics

Total VFA, µ mol/mL 88.0 72.5

Rumen ammonia, mg/dL 23.4 15.5

Digestibility, %

DM 63.7 53.5

CP 76.9 53

Performance

Average daily gain, kg/d 0.73 0.61

Feed:Gain 12.0 13.4Mohanty et al. (25)

Hay Preservatives

Hay preservatives

Reduce losses due to molds & heating

Reduce drying times (can bale at higher T˚C)

Roberts, 2005. https://www.agry.purdue.edu/forageday/2005/article/management%20of%20preservatives-2005_Version3.pdf

Hay Preservatives (cont.)

Preservative Mode of Action

ApplicationMethod

Moisture Content of Hay

Pros & Cons

Weak acid e.g., Propionic acid

Controls mold & bacterialgrowth by altering pH

Liquid-added before baling

Up to 30% Can be stored Corrosive

Buffered acid e.g., Ammonium propionate

Controls mold & bacterial growth


Up to 30% Not ascorrosive

Not as effective

Bacterialinoculants

Compete with other microbes in hay


Up to 23% Cannot be stored

Designed for silage prodn

Hay Storage

Recommended % moisture for safe storage

Bale type % Moisture

Small rectangular bales 16 - 18

Round bales (soft center) 14 - 16

Round bales (hard center) 13 - 15

Large rectangular bales 12 - 14

Export hay < 12

Hay Storage

Protect from the elements

http://hallhall.com/blog/haying-with-the-buffalo-on-colorado-ranches/, http://rurification.blogspot.ca/2012_12_01_archive.html

Hay Storage and Forage Quality


Testing for Forage Quality

Why send forage samples for analysis?

?

?

?

?

Forage Quality Results

How can laboratory results differ when they

are sent the “same” sample?

https://www.progressiveforage.com/forage-production/harvest-and-storage/decreasing-the-variability-in-hay-tests

Forage Quality Results

Accuracy = how closely the quality measurements

of the submitted sample compares to the true

quality of the lot of forage it represents.

Forage Quality Results (cont.)

Precision = the ability of a laboratory to

repeatedly produce the same results.

Accuracy of forage analysis is limited by the

weakest link in the analytical procedure

Sample Collection

https://picclick.com/Hay-Probe-Bale-Sampler-Drill-Type-24-Depth-171080086455.html; https://www.ag.ndsu.edu/carringtonrec/center-points/managing-hay-resources-when-the-sun-won2019t-shine

Hay Sampling Protocols

Reducing sampling error

a. Identify a single hay lot

b. Sample close to the point of sale/feeding

c. Choose a sharp, well-designed probe (3/8 to 3/4

inch)

d. Sample at random (systematically)

Hay Sampling Protocols (cont.)

Reducing sampling error (cont.)

e. Use the proper technique

https://www.progressiveforage.com/forage-production/harvest-and-storage/decreasing-the-variability-in-hay-tests

Hay Sampling Protocols (cont.)

Reducing sampling error (cont.)

f. Take the right amount (1/2 lb or 250 g)

g. Handle the sample properly

h. Never split the sample before grinding it first

i. Choose a qualified lab

Is it certified e.g., National Forage Testing Association

(NFTA)?, Quality control steps?, Procedures, e.g., AOAC?

Quality Guidelines for Alfalfa Hay

http://hayandforage.com/article-1211-USDA-Weekly-Hay-Market-Prices---February-28-2017.html

http://hayandforage.com/article-1211-USDA-Weekly-Hay-Market-Prices---February-28-2017.html

Quality Guidelines for Grass Hay

http://hayandforage.com/article-521-USDA-Hay-Market-Prices-–-February-16-2016.html

http://hayandforage.com/article-521-USDA-Hay-Market-Prices-–-February-16-2016.html

Relative Feed Value (RFV)

Widely used index to market hay

RFV = % Digestible DM × DM intake (% of BW)

1.29

% Digestible DM % = 88.9 – (ADF% × 0.779)

DM intake (% of BW) = 120 ÷ NDF%

Total Digestible Nutrients (TDN)

Index that estimates energy supply

Earlier equations based on ADF;

TDNLegumes and grasses = 88.9 – (0.79 × ADF%)

NRC, 2001

TDN = dNFC + dCP + (dFA × 2.25) + dNDF – 7

Relative Feed Quality (RFQ)

Another forage quality measure

RFQ = TDN × DM intake (% of BW)

1.23

RFV = % Digestible DM × DM intake (% of BW)

1.29

http://www.hayhorsefeeders.com/round-bale-feeders.html

Modification of Forage Quality Post-Harvest

Forage Production

What is the goal of most forage production

systems?

Strategies to achieve that goal?

i. ?

ii. ?

iii. ?

iv. ?

Forage Production (cont.)

In some instances, forage quality cannot be

optimized!

If we cannot grow forages or if forages are too

expensive, what could we use to feed cattle?

Use of Crop Residues as Feed

1 kg of grain

≈ 1 kg of residue

≈ 400 M tonnes of residue/yearhttp://www.startribune.com/ethanol-industry-gets-its-own-corn/290370141/; https://www.pinterest.com/pin/132785888986916857/

Use of Crop Residues as Feed (cont.)

Examples of crop

residues

?

?

?

http://maxpixel.freegreatpicture.com/Straw-Bale-Harvested-Wheat-Field-Summer-853333

Use of Crop Residues as Feed (cont.)

What are the advantages?

i. ?

ii. ?

iii. ?

What is the biggest drawback?

Improving the Nutritive Value of Crop Residues for Livestock

Some form of processing required to;

i. Increase acceptability of high fiber

ii. Increase DMI

iii. Enhance rate and extent of digestion

iv. Increase production performance and economic

returns

Improving the Nutritive Value of Crop Residues for Livestock (cont.)

Types of processing methods;

i. Physical-mechanical

ii. Chemical

iii. Microbiological

Improving the Nutritive Value of Crop Residues for Livestock (cont.)

Problem with processing of residues;

i. Cost of treatment often > value of end product

ii. Treated product may be of low to moderate

value

Might still need to supplement protein &/or

energy!

Physical Treatments: Grinding & Pelleting

Grinding

i. Decreases particle size

ii. Increases surface area

iii. Increases the bulk density

of forages https://buildasoil.com/products/alfalfa-meal

Physical Treatments: Grinding & Pelleting (cont.)

Pelleting

i. Further increases the

bulk density

i. Reduces dustiness

ii. Increases ease of handling http://www.ghatnutrition.com/alfalfa-pellets-17/


Benefits of grinding and pelleting long hay

-60

-40

-20

0

20

40

60

80

100

DMI Daily gain Feed:Gain

% Improvement

Beardsley, 1964. JAS. 23:239-245


Improvements in DMI & ADG inversely

related to unprocessed forage quality!

Grinding & pelleting in combination with protein

supplementation

Chopping = inconsistent improvements


Grinding and pelleting generally depresses

digestibility!

Up to 15% for grasses & 6% for legumes

Greater depression with higher DMI

However, high DMI = high GE intake = high DE intake!


Decrease in digestibility due to reduced fiber

digestion;

Higher DMI = shorter rumen residence time

Decrease in particle size = less time spend time

eating and ruminating

Impact?


Grinding and pelleting often reduces ruminal

digestion of forage protein!

Heat produced during grinding & pelleting

i. Decreases ruminal degradation (increases by-

pass protein)

ii. May cause Maillard reactions

Physical Treatments: Steam Explosion

Primarily used for pre-treatment of

lignocellulosic material for ethanol & biogas

production.

Superheating for a short time

i. Hydrolyzes hemicellulose to sugars

ii. Breaks down lignin bonds with carbohydrates

Physical Treatments: Steam Explosion (cont.)

Some of the reported benefits;

i. Increase in DMI

ii. Increase in DM, NDF, cellulose digestibility

iii. Increase in ADG

iv. Improvement in feed efficiency

Challenge = cost!

Physical Treatments: Mechanical Separation of Plant Parts

Physical Treatments: Mechanical Separation of Plant Parts (cont.)

lignin

Physical Treatments: Mechanical Separation of Plant Parts (cont.)

Leaf fraction Stem fraction

Surface area, mm2/g 13.6 6.6

Ash, g/kg 102 79

Nitrogen, g/kg 15.2 11.2

NDF, g/kg 673 699

ADF, g/kg 384 407

Lignin, g/kg 33.1 51.8

Intake, g/kg of BW0.75 44.2 34.4

NDF digestibility, % 58.9 48.0

ADF digestibility, % 57.6 49.0Laredo and Minson, 1975. Br.J.Nutr. 33:159-170

Physical Treatments: Mechanical Separation of Plant Parts

Improvements must be significant to offset

processing costs e.g.,;

i. Transportation of forages to a central processing

location

ii. Drying of fresh forages prior to separation

(energy intensive)

Chemical Treatments

Involves the use of either;

i. Hydrolytic agents

e.g., NaOH, KOH, Ca(OH)2, NH3, urea

ii. Oxidative agents

e.g., SO2, ozone

iii. Combination of hydrolytic agents and oxidants

Chemical Treatments: Hydrolytic Agents

Hydrolytic treatments

Partially solubilizes hemicellulose, lignin,..

Disruption of H-bonds in cellulose

http://www.intechopen.com/books/cellulose-fundamental-aspects/structural-characteristics-and-thermal-properties-of-native-cellulose

Chemical Treatments: Oxidative Agents

Oxidative treatments

Degrade a proportion of cell wall lignin

http://http://www.intechopen.com/books/ionic-liquids-new-aspects-for-the-future/applications-of-ionic-liquids-in-lignin-chemistry


Hydrolytic agents = Alkali’s e.g., NaOH,

Ca(OH)2, NH3, urea

Disrupt lignocellulosic structure

i. Partially solubilize bonds between lignin, and

cellulose and hemicellulose

ii. Disrupt H-bonds in cellulose

http://www.intechopen.com/books/cellulose-fundamental-aspects/structural-characteristics-and-thermal-properties-of-native-cellulose


Chemical Treatments: NaOH

Used at 3 to 5% of DM

Wet application = soak cereal straw in NaOH

for 3 days and wash off residual chemical

Leaching of nutrients during washing (10-15% DM

loss)

Disposal of residual NaOH


Dry application = spray on forage

Less effective than wet application


73.7

35.9

5.6

67.4

32.6

4.88

0

10

20

30

40

50

60

70

80

NDF ADF Lignin

Effect of NaOH Treatment on Fiber Content (%) of Bermuda grass

Control NAOH trt.

Utley et al., 1982. Can. J. Anim. Sci. 62:499-505


48.8 49.4

43

55.8 55.4

46.8

0

10

20

30

40

50

60

Dry matter NDF ADF

Effect of NaOH Treatment on Nutrient Digestibility (%)

Control NAOH trt.



0.65

11.2

0.69

9.91

0

2

4

6

8

10

12

ADG, kg/d Feed:Gain

Effect of NaOH Treatment on Production Performance

Control NAOH trt.



Treatment issues

i. Hazardous (caustic alkali)

ii. Na accumulation in manure

iii. Expensive

iv. Wet application = leaching + disposal of residual

NaOH

Chemical Treatments: Ca(OH)2

Quicklime, burnt lime (CaO) used

Add water and forms hydrated lime (Ca(OH)2)

CaO + H2O Ca(OH)2 + Heat

Handle with care when mixing!

“Quicklime dust” causes severe irritation!


Chopping: 3 to 6 inches


36.3 36.4 36.7

51.8 50.353.1

0

10

20

30

40

50

60

Dry matter Organic matter NDF

Effect of CaO treatment on Nutrient Digestibility (%) of Corn Stover

Untreated Treated

Shi et al., 2015. J Anim Physiol a Anim Nutr. DOI: 10.1111/jpn.12381


Chemical Treatments: Ammoniation

Most widely used method of alkali treatment

in the US

Not as effective as NaOH treatment

But increase CP content

Works better with poor quality forages/residues

< 5% CP

< 45 – 50% TDN

Chemical Treatments: Ammoniation(cont.)

Application rate = 1.5 to 3% of DM (~60

lb/ton of dry forage)


Key reaction: Anhydrous NH3 (liquid) to gas

(several weeks)

Gas can penetrates forage (but losses)

Better reaction with;

i. High moisture in forage

ii. High ambient temperature


82.1

2.56

31.5

73.9

11.875

51.2

0

10

20

30

40

50

60

70

80

90

NDF content CP content NDF digestibility

Effect of Ammoniation on Nutrient Composition & Digestibility (%) of Wheat Straw

Untreated Treated

Bals et al., 2010. Anim. Feed Sci. Technol. 155:147-155


Increases intake and digestibility

Can partially replace “conventional” hay with

treated straw

Up to 65% in late-gestation cows

Up to 35% in cows nursing calves


Always consider ammoniation cost vs. hay price!

Estimated cost to treat 1 ton of forage:

$26-30 for anhydrous ammonia

$5-9 for plastic

Total = $31-39/ton

If wheat straw = $45-50/ton, ammoniated straw =

$76-89/ton

Chemical Treatments: Urea

Urea used as a source of NH3

Urea NH3 + CO2

Mixed with roughage in silo, pelleter, etc.

Safer than handling anhydrous NH3

Variable results

Moisture content? Urease activity? Temperature?

Urease

Chemical Treatments: Oxidative Agents

Chemical Treatments: Alkaline Hydrogen Peroxide (AHP)

10.4

45.1

25.9

11.5

56.2

2.3

0

10

20

30

40

50

60

Lignin Cellulose Hemicellulose

Effect of AHP Treatment on Nutrient Composition (%) of Wheat Straw

Untreated AHP Treated

Chaudhry, 1998. Anim. Feed Sci. Technol. 74:315-328.

Chemical Treatments: Alkaline Hydrogen Peroxide (AHP)

49.446.4

58.8

76.1

67

85.4

0

10

20

30

40

50

60

70

80

90

NDF ADF Cellulose

Effect of AHP Treatment on Nutrient Composition (%) of Wheat Straw

Untreated AHP Treated

Chaudhry, 1998. Anim. Feed Sci. Technol. 74:315-328.

Chemical Treatments: Peroxides

Effective in improving digestibility

Higher cost than NaOH or NH3 treatment

Not as practical as NaOH of NH3 treatment

Some peroxides are pollutants (e.g., ozone)

Microbial/Enzymatic Treatments

Advantages;

i. Fewer chemicals

ii. Lower energy inputs

Disadvantages;

i. Longer treatment time

ii. Loss of substrate during incubation

Microbial Treatments: White-rot Fungi

Effective in degrading lignocellulosic material

But loss of carbohydrates (CHO);

i. 1st utilize soluble CHO

before producing

lignin-degrading enzymes

ii. Degrade CHO from

delignified cell wallhttp://www.mykoweb.com/articles/DeconstructingDecomposing.html

Enzymatic Treatments

Use of various fiber degrading enzymes;

i. Cellulases,

ii. Xylanases

iii. Ligninases, etc.

Inconsistent results!!

High cost

Summary

AVS 474 Beef Cattle Science - University of Idaho Materials/Forages 2018 (GEC... · Forage is baled vs. ensiled? ii. Small vs. large acreage to harvest? iii. Rain early vs. late in

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