FORAGES Gwinyai E. Chibisa, Ph.D.

Transcription

1 FORAGES Gwinyai E. Chibisa, Ph.D.

2 What is Forage? Characteristics i. Bulky ii. iii. Implications on animal nutrition? High fiber Is fiber important? Lower digestibility than grains High quality (60 68%) E.g.,? Medium quality (53 59%) E.g.,? Low quality (<53%) E.g.,?

3 What is Forage Quality? The extent to which a forage has the potential to produce a desired animal response Key responses? i.? ii.? iii.?

4 Forage Quality is Milk in the Bucket Ball et al, American Farm Bureau Federation Publication 1-01

5 Forage Quality is Calves on the Ground Ball et al, American Farm Bureau Federation Publication 1-01

6 Forage Quality is Pounds on The Scale Ball et al, American Farm Bureau Federation Publication 1-01

7 Forage Quality Factors that affect animal responses? i. Nutrient composition? ii. iii. iv. Palatability? Intake? Digestibility? v. Anti-quality factors?

8 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?

9 Plant Cells NDF? ADF?

10 Forage Nutrient Composition Ball et al, American Farm Bureau Federation Publication 1-01

11 Forage Fiber & Nutritive Value Ball et al, American Farm Bureau Federation Publication 1-01

12 Forage Fiber (NDF & ADF) Determination

13 What Happens to NDF in the Rumen? Gaylean and Owens, Proc. Of the Southwest Nutrition & Management Conference

14 Dietary NDF and DMI (and ph) DMI ph Zebeli et al., JDS. 95:

15 Estimating DMI (as % of BW) DMI (% of BW) = 120 %NDF Forage Quality NDF, % DMI, % of BW Excellent Poor

16 ADF and Digestibility Undersander,

17 Estimating % Digestible DM % Digestible DM = 88.9 (ADF% 0.779) ADF, % DDM, %

18 Effects of ADF and NDF on Hay Price Putnam et al., Irrigated Alfalfa Management in Mediterranean & Desert Zones

19 Forage Quality (cont.) Factors that influence forage quality? i. Maturity stage ii. Leaf-to-stem ratio Species differences Grasses vs. Legumes Cool-season vs. Warm-season iii. iv. Variety differences Growth conditions v. Harvesting & Storage conditions

20 i. Maturity, Yield & Quality

21 Maturity Stage lignin

22 Lignification and Digestibility Lignin (% of NDF) Jung, Proceedings: Florida Ruminant Nutrition Symposium

23 Examples of Changes in Forage Quality with Maturity U.S.-Canadian tables of feed composition, third edition

24 ii. Grasses vs. Legumes Crude protein Cell wall/fiber Lignin Energy Minerals (E.g., Ca & Mg) Bloat Grasses Legumes

25 ii. Grasses vs. Legumes (cont.) Ball et al, American Farm Bureau Federation Publication 1-01

26 Grasses Non-leguminous, require less management Cool-season vs. warm-season Keyser, UT Ext. Pub. SP731-A

27 Cool vs. Warm-Season Grasses Navarrete-Tindall Missouri Prairie Journal. 31:20-25

28 Cool Season Grasses i. Orchardgrass ii. Bromegrass iii. Tall Fescue iv. Ryegrass v. Bluegrass vi. Wheatgrass vii. Red Canarygrass viii. Timothy, etc.

29 Cool Season: Orchardgrass

30 Cool Season: Orchardgrass (cont.) Shade tolerant perennial Much of PNW irrigated pasture Highly productive Highly palatable Compatible with alfalfa/clover mixes Marginal winter hardiness

31 Cool Season: Smooth brome

32 Cool Season: Smooth brome (cont.) Shade tolerant, Winter hardy Highly productive, Slow regrowth Very palatable High protein content Erosion control e.g., Lincoln

33 Cool Season: Downy brome

34 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!

35 Cool Season: Tall Fescue

36 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)

37 Endophyte fungus Produces ergot alkaloids Ergovaline Lysergic acid

38 Ergot Alkaloids Biogenic amines e.g., Serotonin & Dopamine Numerous negative effects e.g., compromised neurological function, embryonic loss Ergot alkaloids e.g., Lysergic acid

39 Tall Fescue Toxicity Losses of up to US$2 Billion/year Kallenbach, J. Anim. Sci. 93:

40 Tall Fescue Toxicity Kallenbach, J. Anim. Sci. 93:

41 Tall Fescue Toxicity (cont.) Fescue foot, heat stress

42 Cool Season Grasses Refer to Improved grasses and legumes for Idaho for information on the following: iv. Ryegrass v. Bluegrass vi. vii. Wheatgrass Red Canarygrass viii. Timothy

43 Warm Season Grasses i. Bermudagrass ii. iii. iv. Bahia Switchgrass Bluestem v. Bluegrass vi. Indiangrass, etc.

44 Warm Season Annuals i. Sorghum ii. iii. Sudan grass Sorghum Sudan hybrids High alkaline soil tolerant Drought tolerant Very productive Prussic acid & nitrate poisoning?

45 Prussic Acid Poisoning (Cyanogenic glucoside) (Hydrogen cyanide/prussic Acid) Plant HCN content influenced by: Stage of growth, Drought, Frost, etc. HCN + Hemoglobin Cyanoglobin

46 Nitrate Toxicity Plant nitrate content influenced by: Drought & high T C, Lack of sunlight, disease etc.

47 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)

48 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.

49 Legumes i. Alfalfa ii. iii. iv. Birdsfoot Trefoil Red Clover White Clover v. Sainfoin vi. Annual legumes e.g., beans, peas

50 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

51 Alfalfa Queen of Forages

52 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

53 Structural Components of Alfalfa Ball et al, American Farm Bureau Federation Publication 1-01

54 Alfalfa Queen of Forages (cont.) Needs well-drained soils Heaving Winterkill Low tolerance to overgrazing Low NSC relative to soluble CP Bloat problems

55 Bloat Accumulation of gasses Gas Bloat guard - Poloxalene

56 Birdsfoot Trefoil

57 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

58 Legumes i. Alfalfa ii. iii. iv. Birdsfoot Trefoil Red Clover White Clover v. Sainfoin vi. Annual legumes e.g., beans, peas

59 Red Clover

60 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

61 Phytoestrogens E.g, Isoflavones (Formononetin) Plant content varies Genetics Use of low-phytoestrogen varieties Environmental conditions E.g., fertilizer deficiency

62 Phytoestrogens (cont.) Mimic estradiol Estradiol Isoflavone, e.g., Formononetin Clover disease Low lambing rates, uterine prolapse, dystocia, death Temporary or permanent infertility ( defeminization )

63 White Clover

64 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

65 Sainfoin E.g., Shoshone

66 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

67 Annual Legumes E.g., Beans (Faba s), Peas Cool-season Good as silage or for grazing

68 Summary - Legumes i. High quality forage Opportunity to mix with grasses ii. iii. Reduce the cost of N fertilization Potential issues Bloat, Phytoestrogens

69 Forage Preservation

70 Forage Preservation Why do we preserve forages? i.? ii.? iii.?

71 Forage Preservation (cont.) What are the common preservation methods? i.? ii.? iii.?

72 Forage Preservation (cont.) What are the factors to consider? i.? ii.? iii.?

73 Forage Preservation (cont.) Is forage preservation a perfect process? Fresh Vegetation Preserved Forage DM Losses Quality Loss

74 Dry Matter Loss Losses due to: i. Plant metabolism ii. iii. Microbial metabolism Physical processes

75 What is hay? Hay

76 Haymaking Objectives i. Produce a high yielding, high quality crop ii. iii. iv. Rapid curing Minimize leaf loss Minimize cell respiration v. Avoid leaching losses & molding vi. Maintain quality in storage

77 Haymaking Objectives i. Produce a high yielding, high quality crop ii. iii. iv. Rapid curing Minimize leaf loss Minimize cell respiration v. Avoid leaching losses & molding vi. Maintain quality in storage

78 Haymaking Phases Harvesting/Cutting Curing Raking Baling Storage

79 Harvesting

80 When to Harvest? Impact of plant maturity on DMI & digestibility Ball et al, American Farm Bureau Federation Publication 1-01

81 When to Harvest? Forage Species Time of Harvest Alfalfa Bud stage (1 st cutting); 1/10 bloom for 2 nd and later cuts Orchardgrass, Tall Fescue Red Clover Barley, Oats, Rye, Wheat Sudan-sorghum hybrids Weather conditions? Boot to early head (1 st cut); every 4-6 weeks after Early to ½ bloom. Boot to early head stage. Early boot stage.

82 Curing What is the objective of curing??

83 Curing (cont.) Factors that affect the duration of curing Initial DM% Environmental i. Temperature ii. iii. iv. Humidity Wind speed Solar radiation Conditioning

84 How Does Rain Affect Hay Quality i. Leaching (soluble CHO, CP, minerals) ii. iii. iv. Increased and prolonged respiration Leaf shattering Microbial activity v. Color bleaching

85 Make Hay While The Sun Shines Ball et al, American Farm Bureau Federation Publication 1-01

86 What Would You Do? If forage is ready to harvest for hay, but rain is in the forecast?

87 Risk Assessment If you were to go ahead, which of the following has the higher risk? i. Forage is baled vs. ensiled? ii. iii. iv. Small vs. large acreage to harvest? Rain early vs. late in drying period? Forecasted rain is full-frontal vs. scattered? v. Grass vs. Grass-legume mix vs. legume? vi. Market for damaged hay, drying agents, etc

88 Curing (cont.) Factors that affect the duration of curing Initial DM% Environmental i. Temperature ii. iii. iv. Humidity Wind speed Solar radiation Conditioning

89 Conditioning Treatment of hay crop to accelerate the drying process. Mechanical and/or Chemical conditioning

90 Mechanical Conditioning Conditioners bruise, lacerate, crush or crimp plant to reduce differential drying of leaves vs. stems

91 Chemical Conditioning Desiccants/ drying agents E.g., K 2 CO 3, NaCO 3

92 Reducing Drying Time Tedding

93 Reducing Drying Time Raking

94 Baling Has to be done at the correct moisture % moisture? Consequences of baling when too wet or dry?

95 DM Losses During Haymaking Ball et al, American Farm Bureau Federation Publication 1-01

96 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 Baling (rectangular) 2-5 Baling (large, round) 15-40

97 Baling When Too Wet Growth of spoilage microbes (aerobic) Spoilage bacteria, e.g., bacilli Yeasts, molds, fungi Hay (plant sugars, protein) + O 2 CO 2 + H 2 O + Heat

98 Effect of Feeding Moldy Hay in Cattle Parameter Good Hay Moldy Hay Hay intake, kg Rumen fermentation characteristics Total VFA, µ mol/ml Rumen ammonia, mg/dl Digestibility, % DM CP Performance Average daily gain, kg/d Feed:Gain Mohanty et al. (25)

99 Hay Preservatives Hay preservatives Reduce losses due to molds & heating Reduce drying times (can bale at higher T C) Roberts,

100 Hay Preservatives (cont.) Preservative Mode of Action Application Method Moisture Content of Hay Pros & Cons Weak acid e.g., Propionic acid Controls mold & bacterial growth by altering ph Liquid-added before baling Up to 30% Can be stored Corrosive Buffered acid e.g., Ammonium propionate Controls mold & bacterial growth Liquid-added before baling Up to 30% Not as corrosive Not as effective Bacterial inoculants Compete with other microbes in hay Liquid-added before baling Up to 23% Cannot be stored Designed for silage prodn

101 Hay Storage Recommended % moisture for safe storage Bale type % Moisture Small rectangular bales Round bales (soft center) Round bales (hard center) Large rectangular bales Export hay < 12

102 Hay Storage Protect from the elements

103 Hay Storage and Forage Quality Ball et al, American Farm Bureau Federation Publication 1-01

104 Testing for Forage Quality Why send forage samples for analysis?????

105 Forage Quality Results How can laboratory results differ when they are sent the same sample?

106 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.

107 Forage Quality Results (cont.) Precision = the ability of a laboratory to repeatedly produce the same results.

108 Sample Collection Accuracy of forage analysis is limited by the weakest link in the analytical procedure

109 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)

110 Hay Sampling Protocols (cont.) Reducing sampling error (cont.) e. Use the proper technique

111 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?

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115 Quality Guidelines for Alfalfa Hay

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117 Quality Guidelines for Grass Hay -February html

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119 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%

120 Total Digestible Nutrients (TDN) Index that estimates energy supply Earlier equations based on ADF; TDN Legumes and grasses = 88.9 (0.79 ADF%) NRC, 2001 TDN = dnfc + dcp + (dfa 2.25) + dndf 7

121 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

122 Modification of Forage Quality Post-Harvest

123 Forage Production What is the goal of most forage production systems? Strategies to achieve that goal? i.? ii.? iii.? iv.?

124 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?

125 Use of Crop Residues as Feed 1 kg of grain 1 kg of residue 400 M tonnes of residue/year

126 Use of Crop Residues as Feed (cont.) Examples of crop residues???

127 Use of Crop Residues as Feed (cont.) What are the advantages? i.? ii.? iii.? What is the biggest drawback?

128 Improving the Nutritive Value of Crop Residues for Livestock Some form of processing required to; i. Increase acceptability of high fiber ii. iii. iv. Increase DMI Enhance rate and extent of digestion Increase production performance and economic returns

129 Improving the Nutritive Value of Crop Residues for Livestock (cont.) Types of processing methods; i. Physical-mechanical ii. iii. Chemical Microbiological

130 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!

131 Physical Treatments: Grinding & Pelleting Grinding i. Decreases particle size ii. iii. Increases surface area Increases the bulk density of forages

132 Physical Treatments: Grinding & Pelleting (cont.) Pelleting i. Further increases the bulk density i. Reduces dustiness ii. Increases ease of handling

133 Physical Treatments: Grinding & Pelleting (cont.) Benefits of grinding and pelleting long hay 100 % Improvement DMI Daily gain Feed:Gain Beardsley, JAS. 23:

134 Physical Treatments: Grinding & Pelleting (cont.) Improvements in DMI & ADG inversely related to unprocessed forage quality! Grinding & pelleting in combination with protein supplementation Chopping = inconsistent improvements

135 Physical Treatments: Grinding & Pelleting (cont.) 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!

136 Physical Treatments: Grinding & Pelleting (cont.) 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?

137 Physical Treatments: Grinding & Pelleting (cont.) Grinding and pelleting often reduces ruminal digestion of forage protein! Heat produced during grinding & pelleting i. Decreases ruminal degradation (increases bypass protein) ii. May cause Maillard reactions

138 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

139 Physical Treatments: Steam Explosion (cont.) Some of the reported benefits; i. Increase in DMI ii. iii. iv. Increase in DM, NDF, cellulose digestibility Increase in ADG Improvement in feed efficiency Challenge = cost!

140 Physical Treatments: Mechanical Separation of Plant Parts

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

142 Physical Treatments: Mechanical Separation of Plant Parts (cont.) Leaf fraction Stem fraction Surface area, mm 2 /g Ash, g/kg Nitrogen, g/kg NDF, g/kg ADF, g/kg Lignin, g/kg Intake, g/kg of BW NDF digestibility, % ADF digestibility, % Laredo and Minson, Br.J.Nutr. 33:

143 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)

144 Chemical Treatments Involves the use of either; i. Hydrolytic agents e.g., NaOH, KOH, Ca(OH) 2, NH 3, urea ii. Oxidative agents e.g., SO 2, ozone iii. Combination of hydrolytic agents and oxidants

145 Chemical Treatments: Hydrolytic Agents Hydrolytic treatments Partially solubilizes hemicellulose, lignin,.. Disruption of H-bonds in cellulose

146 Chemical Treatments: Oxidative Agents Oxidative treatments Degrade a proportion of cell wall lignin

147 Chemical Treatments: Hydrolytic Agents Hydrolytic agents = Alkali s e.g., NaOH, Ca(OH) 2, NH 3, urea Disrupt lignocellulosic structure i. Partially solubilize bonds between lignin, and cellulose and hemicellulose ii. Disrupt H-bonds in cellulose

148 Chemical Treatments: Hydrolytic Agents

149 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

150 Chemical Treatments: NaOH Dry application = spray on forage Less effective than wet application

151 Chemical Treatments: NaOH Effect of NaOH Treatment on Fiber Content (%) of Bermuda grass NDF ADF Lignin Control NAOH trt. Utley et al., Can. J. Anim. Sci. 62:

152 Chemical Treatments: NaOH 60 Effect of NaOH Treatment on Nutrient Digestibility (%) Dry matter NDF ADF Control NAOH trt. Utley et al., Can. J. Anim. Sci. 62:

153 Chemical Treatments: NaOH Effect of NaOH Treatment on Production Performance ADG, kg/d 0.69 Control NAOH trt. Feed:Gain Utley et al., Can. J. Anim. Sci. 62:

154 Chemical Treatments: NaOH Treatment issues i. Hazardous (caustic alkali) ii. iii. iv. Na accumulation in manure Expensive Wet application = leaching + disposal of residual NaOH

155 Chemical Treatments: Ca(OH) 2 Quicklime, burnt lime (CaO) used Add water and forms hydrated lime (Ca(OH) 2 ) CaO + H 2 O Ca(OH) 2 + Heat Handle with care when mixing! Quicklime dust causes severe irritation!

156 Chopping: 3 to 6 inches Chemical Treatments: Ca(OH) 2

157 Chemical Treatments: Ca(OH) Effect of CaO treatment on Nutrient Digestibility (%) of Corn Stover Dry matter Organic matter NDF Untreated Treated Shi et al., J Anim Physiol a Anim Nutr. DOI: /jpn.12381

158 Chemical Treatments: Ca(OH)2

159 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

160 Chemical Treatments: Ammoniation (cont.) Application rate = 1.5 to 3% of DM (~60 lb/ton of dry forage)

161 Chemical Treatments: Ammoniation (cont.) Key reaction: Anhydrous NH 3 (liquid) to gas (several weeks) Gas can penetrates forage (but losses) Better reaction with; i. High moisture in forage ii. High ambient temperature

162 Chemical Treatments: Ammoniation (cont.) Effect of Ammoniation on Nutrient Composition & Digestibility (%) of Wheat Straw NDF content CP content NDF digestibility Untreated Treated Bals et al., Anim. Feed Sci. Technol. 155:

163 Chemical Treatments: Ammoniation (cont.) 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

164 Chemical Treatments: Ammoniation (cont.) 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

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169 Chemical Treatments: Urea Urea used as a source of NH 3 Urease Urea NH 3 + CO 2 Mixed with roughage in silo, pelleter, etc. Safer than handling anhydrous NH 3 Variable results Moisture content? Urease activity? Temperature?

170 Chemical Treatments: Oxidative Agents

171 Chemical Treatments: Alkaline Hydrogen Peroxide (AHP) Effect of AHP Treatment on Nutrient Composition (%) of Wheat Straw Lignin Cellulose Hemicellulose Untreated AHP Treated Chaudhry, Anim. Feed Sci. Technol. 74:

172 Chemical Treatments: Alkaline Hydrogen Peroxide (AHP) Effect of AHP Treatment on Nutrient Composition (%) of Wheat Straw NDF ADF Cellulose Untreated AHP Treated 85.4 Chaudhry, Anim. Feed Sci. Technol. 74:

173 Chemical Treatments: Peroxides Effective in improving digestibility Higher cost than NaOH or NH 3 treatment Not as practical as NaOH of NH 3 treatment Some peroxides are pollutants (e.g., ozone)

174 Microbial/Enzymatic Treatments Advantages; i. Fewer chemicals ii. Lower energy inputs Disadvantages; i. Longer treatment time ii. Loss of substrate during incubation

175 Microbial Treatments: White-rot Fungi Effective in degrading lignocellulosic material But loss of carbohydrates (CHO); i. 1 st utilize soluble CHO before producing lignin-degrading enzymes ii. Degrade CHO from delignified cell wall

176 Enzymatic Treatments Use of various fiber degrading enzymes; i. Cellulases, ii. iii. Xylanases Ligninases, etc. Inconsistent results!! High cost

177 Summary