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In Situ Degradation Kinetics of 25 Feedstuffs and the Selection of Time Points in Mathematical Statistics. Animals (Basel) 2023; 13:ani13050947. [PMID: 36899804 PMCID: PMC10000142 DOI: 10.3390/ani13050947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/27/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023] Open
Abstract
Rumen degradation kinetics of 25 feedstuffs (six protein feeds, nine energy feeds and ten roughages) were first determined using the nylon bag technique in situ and the differences of degradation characteristics fitted with five or seven time points measuring data were evaluated with the goodness of fit (R2) of degradation curves. Protein and energy feeds were incubated for 2, 4, 8, 16, 24, 36, 48 h, roughages were incubated for 4, 8, 16, 24, 36, 48, 72 h, where three and six data sets of five time points were screened out, respectively. Only the degradation parameters a (rapidly degraded proportion), b (slowly degraded proportion) and c (degradation rate of slowly degraded proportion) of several feeds at five time points were significantly different from those at seven time points (p < 0.05), and the others were not significant (p > 0.05). The R2 of the degradation curves obtained at five time points was closer to 1, indicating that the fitting obtained at five time points was more accurate in predicting the real-time rumen degradation rate of feed. These results indicate that it is feasible to determine the rumen degradation characteristics of feedstuffs by only setting five measuring time points.
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Hojilla-Evangelista MP, Selling GW, Hatfield R, Digman M. Extraction, composition, and functional properties of dried alfalfa (Medicago sativa L.) leaf protein. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2017; 97:882-888. [PMID: 27198121 DOI: 10.1002/jsfa.7810] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 04/22/2016] [Accepted: 05/15/2016] [Indexed: 05/14/2023]
Abstract
BACKGROUND Alfalfa is considered a potential feedstock for biofuels; co-products with value-added uses would enhance process viability. This work evaluated dried alfalfa leaves for protein production and describes the functional properties of the protein. RESULTS Dried alfalfa leaves contained 260 g kg-1 dry basis (DB) crude protein, with albumins being the major fraction (260 g kg-1 of total protein). Alkali solubilization for 2 h at 50 °C, acid precipitation, dialysis, and freeze-drying produced a protein concentrate (600 g kg-1 DB crude protein). Alfalfa leaf protein concentrate showed moderate solubility (maximum 500 g kg-1 soluble protein from pH 5.5 to 10), excellent emulsifying properties (activity 158-219 m2 g-1 protein, stability 17-49 min) and minimal loss of solubility during heating at pH ≥ 7.0. CONCLUSIONS It is technically feasible to extract protein with desirable emulsifying and heat stability properties from dried alfalfa leaves; however, the dried form may not be a practical starting material for protein production, given the difficulty of achieving high yields and high-purity protein product. © 2016 Society of Chemical Industry.
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Affiliation(s)
- Mila P Hojilla-Evangelista
- Plant Polymer Research Unit, National Center for Agricultural Utilization Research (NCAUR), USDA Agricultural Research Service (ARS), 1815 N. University St, Peoria, IL, 61604, USA
| | - Gordon W Selling
- Plant Polymer Research Unit, National Center for Agricultural Utilization Research (NCAUR), USDA Agricultural Research Service (ARS), 1815 N. University St, Peoria, IL, 61604, USA
| | - Ronald Hatfield
- United States Dairy Forage Research Center, USDA ARS, 1925 Linden Drive West, Madison, WI, 53706, USA
| | - Matthew Digman
- United States Dairy Forage Research Center, USDA ARS, 1925 Linden Drive West, Madison, WI, 53706, USA
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Affiliation(s)
- John A. Rooke
- Research and Development Division; SAC; Aberdeen United Kingdom
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Affiliation(s)
- William P. Weiss
- Department of Animal Sciences; The Ohio State University; Wooster Ohio
| | | | - Carl W. Hunt
- Department of Animal and Veterinary Science; University of Idaho; Moscow Idaho
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5
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Gilbery T, Lardy G, Bauer M. Characterizing the ensiling properties of sugarbeets with dry feedstuffs. Anim Feed Sci Technol 2010. [DOI: 10.1016/j.anifeedsci.2009.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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6
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Hersom MJ. Opportunities to enhance performance and efficiency through nutrient synchrony in forage-fed ruminants. J Anim Sci 2007; 86:E306-17. [PMID: 17940154 DOI: 10.2527/jas.2007-0463] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Increasingly, the need for optimized nutrient utilization to address increasing production costs and environmental considerations will necessitate opportunities to improve nutrient synchrony. Historically, attempts at synchronizing nutrient supply in ruminants, particularly in cattle consuming high-forage diets, have met with variable results. The success of nutrient synchrony has been measured primarily in ruminants by increases in microbial yield, microbial efficiency, nutrient utilization, and to a lesser extent, animal performance. Successful synchrony of nutrient supply to cattle consuming forage-based diets faces several challenges. From a feed supply aspect, the challenges to nutrient synchrony include accurately measuring forage intake and consumed forage chemical composition. The issue of forage intake and chemical composition is perhaps the most daunting for producers grazing cattle. Indeed, for forage-fed cattle, the availability of forage protein and carbohydrate can be the most asynchronous aspect of the diet. In most grazed forages, digestion rates of the carbohydrate fractions are much slower than that of the corresponding protein fractions. Additionally, the forage-supplement interaction exerts a large impact on the synchrony of nutrients. The supplemental feedstuffs compose the component of the nutrient synchrony scenario that is most often manipulated to influence synchrony. The supplement type (e.g., starch vs. fiber, dry vs. liquid), nutrient profile, and degradation rates are often prime considerations associated with nutrient synchrony on high forage diets. Other considerations that warrant attention include temporal intake patterns of the forage and supplement, increased use and types of coproduct supplements, and an assessment of the success of nutrient synchrony. Synchronization of nutrient utilization by forage-fed ruminants has and will continue to encounter challenges for successful outcomes. Ultimately it is the improvement in animal performance and optimization of nutrient utilization efficiency that dictates whether nutrient synchrony is a successful strategy.
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Affiliation(s)
- M J Hersom
- Department of Animal Sciences, University of Florida, Gainesville, Florida 32611-0910, USA.
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Scharenberg A, Arrigo Y, Gutzwiller A, Wyss U, Hess HD, Kreuzer M, Dohme F. Effect of feeding dehydrated and ensiled tanniferous sainfoin (Onobrychis viciifolia) on nitrogen and mineral digestion and metabolism of lambs. Arch Anim Nutr 2007; 61:390-405. [DOI: 10.1080/17450390701565081] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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9
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Physico-chemical characteristics and degradation rate of soluble protein obtained from the washout fraction of feeds. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.livprodsci.2005.05.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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10
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Yang CMJ. Proteolysis, Fermentation Efficiency, and In Vitro Ruminal Digestion of Peanut Stover Ensiled with Raw or Heated Corn. J Dairy Sci 2005; 88:2903-10. [PMID: 16027205 DOI: 10.3168/jds.s0022-0302(05)72971-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Peanut stover (PS) is similar to full-bloom alfalfa hay in chemical composition. The objective of this study was to assess the effect of adding raw or heated corn meal to PS at ensiling on silage N components, fermentation acids, and digestion by ruminal microorganisms. The PS was collected after harvesting of peanuts and ensiled immediately without and with addition of raw or heated corn meal (100 g/kg of fresh weight). Corn was added to PS so that the initial mixture would contain adequate dry matter (DM) (approximately 30%) and additional nonfiber carbohydrate to enhance silage fermentation. After 8 wk of silo fermentation, corn-treated silages contained less structural carbohydrates but more non-fiber carbohydrates compared with the untreated control. A shift from hemicellulose to nonfiber carbohydrate use during silage fermentation was evident by corn treatment. Additional corn at ensiling resulted in silage N with less water-soluble N, protein N, nonprotein N, nonprotein nonammonia N (peptides plus amino acids), and ammonia N. Based on changes in soluble nonprotein N before and after ensiling, the amount of proteolysis was approximately 66% for control silage and was nearly 40% lower in response to corn treatment. Adding corn increased silage lactic acid, but both acetic and propionic acids decreased. These changes were reflected in the lower pH and higher fermentation efficiency with corn-treated silages. More DM was digested and greater amounts of volatile fatty acids, except for branched-chain acids, were produced in vitro by ruminal microorganisms with corn-treated silages. In addition, incubations with silage treated with heated corn contained higher concentrations of acetic and propionic acids compared with raw corn. In vitro ammonia accumulation per unit of DM digested was lower for corn treatments than the control, and for heated corn vs. raw corn-treated silage. These results indicate that supplementation of either raw or heated corn on PS at ensiling could minimize proteolysis and improve fermentation efficiency. Advantages from using heated vs. raw corn could extend beyond silage fermentation and include rumen microbial fermentation.
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Affiliation(s)
- C-M J Yang
- Department of Animal Science, National I-Lan University, I-Lan, Taiwan 26015, Republic of China.
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11
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Adjorlolo LK, Amaning-Kwarteng K, Fianu FK. Preference of sheep for three forms of mucuna forage and the effect of supplementation with mucuna forage on the performance of sheep. Trop Anim Health Prod 2004; 36:145-56. [PMID: 14998313 DOI: 10.1023/b:trop.0000012102.42938.90] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Assessment of the preference of sheep for fresh, dried or ensiled forms of mucuna (Mucuna pruriens var utilis) forage was followed by investigations into the effect of supplementing straw-based diets with the forage. Four sheep were offered fresh, dried and ensiled forms of the forage in a cafeteria style to assess their preference. In the second experiment, 20 sheep were randomly assigned to four dietary treatments, namely, alkali-treated straw only (M0), treated straw supplemented with mucuna forage at 0.3% (M10), 0.6% (M20) or 0.75% (M25) of body weight (approximately 10%, 20% and 25%, respectively, of the total dry matter intake). The daily feed intakes were determined and the sheep were weighed weekly for 10 weeks. The sheep showed a marked preference for fresh mucuna forage over either the dried or ensiled forms. The total dry matter intake increased by 15% and 21%, respectively, with M20 and M25. All the groups lost weight over the feeding period. However, only M0 gave weight losses during the second half of the feeding period. The feed conversion efficiency followed a trend similar to that for weight gains. M20 had the greatest effect on growth and feed conversion efficiency.
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Affiliation(s)
- L K Adjorlolo
- Agricultural Research Station, University of Ghana, PO Box 38, Legon-Accra, Ghana, West Africa.
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Ensiling forage garland (Chrysanthemum coronarium L.) at two stages of maturity and at different wilting levels. Anim Feed Sci Technol 2003. [DOI: 10.1016/s0377-8401(03)00123-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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13
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Volden H, Mydland LT, Olaisen V. Apparent ruminal degradation and rumen escape of soluble nitrogen fractions in grass and grass silage administered intraruminally to lactating dairy cows1. J Anim Sci 2002. [DOI: 10.1093/ansci/80.10.2704] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Hoffman PC, Brehm NM, Combs DK, Bauman LM, Peters JB, Undersander DJ. Predicting the effect of proteolysis on ruminal crude protein degradation of legume and grass silages using near-infrared reflectance spectroscopy. J Dairy Sci 1999; 82:756-63. [PMID: 10212462 DOI: 10.3168/jds.s0022-0302(99)75293-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Two studies were conducted to assess whether routine applications of near infrared reflectance spectroscopy could predict the effects of silage proteolysis on ruminal crude protein (CP) degradation of legume and grass silages. A preliminary study was conducted to assess the effect of laboratory drying method on ruminal CP degradation of silages. Thirty legume and grass silages were freeze-, oven-, or microwave-dried and incubated in situ in the ventral rumen of three ruminally cannulated cows for 24 h. Freeze-drying was considered least likely to alter ruminal CP degradation of the silages; therefore, oven- and microwave-drying were compared using first-order regression with freeze-drying. Oven-drying for 48 h at 55 degrees C compared favorably (R2 = 0.84) with freeze-drying. Microwave-drying resulted in a large bias (2.84 g/10(-1) kg of CP) and was poorly related (R2 = 0.48) to freeze-drying. In a second study, alfalfa and timothy were cut at three maturities and allowed to wilt for 0, 10, 24, 32, 48, and 54 h. Forages were ensiled in triplicate cylindrical mini silos and allowed to ferment for 120 d. After fermentation, silages were oven-dried, ground, and scanned on a near-infrared reflectance spectrophotometer. Duplicate, dried, 2-mm ground silage samples were incubated in the ventral rumen of three ruminally cannulated cows for 24 h. Forage species, maturity, and wilting time significantly affected 24-h ruminal CP degradation of the silages. Near-infrared reflectance spectroscopy accurately predicted (R2 = 0.91) 24-h ruminal CP degradation of silages. Data suggest near-infrared reflectance spectroscopy can accurately assess the effects of forage species, maturity, and wilting time (proteolysis) on 24-h ruminal CP degradation of legume and grass silages.
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Affiliation(s)
- P C Hoffman
- Department of Dairy Science, University of Wisconsin, Madison 53706, USA
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15
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Davies DR, Merry RJ, Williams AP, Bakewell EL, Leemans DK, Tweed JK. Proteolysis during ensilage of forages varying in soluble sugar content. J Dairy Sci 1998; 81:444-53. [PMID: 9532499 DOI: 10.3168/jds.s0022-0302(98)75596-1] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The effect of contrasting concentrations of water-soluble carbohydrates of herbage on silage fermentation and composition was examined using grass with high [250 g/kg of dry matter (DM)] concentrations of water-soluble carbohydrates and grass and clover with low (66 g/kg of DM) concentrations of water-soluble carbohydrates. Herbages were ensiled untreated, after inoculation with lactic acid bacteria, or after treatment with formic acid. Good quality silages were produced from herbage with high concentrations of water-soluble carbohydrates, regardless of treatment, and all pH values were below 3.7 after 90 d of ensilage. However, the silage formed from inoculated herbage had a significantly lower concentration of ammonia N and a significantly higher proportion of residual ribulose-1,5-bisphosphate carboxylase compared with the other two silages. Fast protein liquid chromatography (Pharmacia, Uppsala, Sweden) was used to measure ribulose-1,5-bisphosphate carboxylase, and measurement of true plant protein fractions in herbage and silage showed benefits over traditional measurements such as the measurement of N and ammonia N. Herbages with low concentrations of water-soluble carbohydrates produced inferior quality silages that had lower ribulose-1,5-bisphosphate carboxylase contents and higher ammonia N contents, regardless of treatment; few significant differences were observed among treatments. Under good ensiling conditions, when available water-soluble carbohydrate is adequate, the use of inoculants can improve fermentation characteristics and increase the ribulose-1,5-bisphosphate carboxylase content of silages. However, when the herbage has low concentrations of water-soluble carbohydrates, even in inoculated herbages, lactic acid bacteria may follow a heterofermentative pathway instead of a homofermentative pathway, which can result in a decrease in silage quality and a reduction in intact ribulose-1,5-bisphosphate carboxylase.
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Affiliation(s)
- D R Davies
- Institute of Grassland, Aberystwyth, Ceredigion, United Kingdom
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16
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Messman MA, Weiss WP, Albrecht KA. In situ disappearance of individual proteins and nitrogen from legume forages containing varying amounts of tannins. J Dairy Sci 1996; 79:1430-5. [PMID: 8880467 DOI: 10.3168/jds.s0022-0302(96)76501-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In situ degradability of N and proteins were studied in one cultivar of alfalfa and red clover and two cultivars each of birdsfoot trefoil and sericea lespedeza. Concentrations of tannic acid equivalents (percentage of DM) were 0.68 in one cultivar of birds-foot trefoil and 1.77 and 2.78 in the two cultivars of lespedeza. The other forages contained essentially no tannins. Forage samples were digested in situ for 0, 2, 4, 6, and 12 h. The amount of N remaining at 12 h was positively correlated with concentrations of tannin. About 38% of the N remained after 12 h in forages with no or low concentrations of tannins, and 86% remained in the two cultivars of lespedeza. Total electrophoretically identified proteins followed similar trends, but the percentage remaining was less than that for N. For all forages, bands were found at molecular masses of 15, 30, 45, 47, and 54 kDa. The percentage of 54-kDa protein that remained after 12 h was less than that for the other four proteins (23% vs. 37%). No interaction was found between forage cultivar and protein species. These results showed that tannins reduced ruminal degradation of proteins and that specific forage proteins degraded at different rates that were independent of tannin concentration.
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Affiliation(s)
- M A Messman
- Department of Animal Sciences, Ohio Agricultural Research and Development Center, Ohio State University, Wooster 44691
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Peltekova VD, Broderick GA. In vitro ruminal degradation and synthesis of protein on fractions extracted from alfalfa hay and silage. J Dairy Sci 1996; 79:612-9. [PMID: 8744226 DOI: 10.3168/jds.s0022-0302(96)76406-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Net release of degraded N as NH3 and total AA plus microbial protein synthesis, quantified from incorporation of 15NH3 into microbial protein, was used to estimate the rate and extent of in vitro degradation of protein fractions isolated from alfalfa hay and silage. Seven proteins (casein, alfalfa hay, alfalfa silage, extracts from alfalfa hay and silage, and residues from alfalfa hay and silage) were studied. Results from (NH4)2SO4 and SDS-PAGE fractionations suggested that soluble proteins in alfalfa hay and silage differed in susceptibility to proteolytic attack. Although the net release of NH3 plus total AA N from alfalfa silage and alfalfa silage extract was twofold greater than that from alfalfa hay and alfalfa hay extract, net microbial protein synthesis on alfalfa hay and alfalfa hay extract was 33 and 43% greater. Despite greater NPN content in alfalfa silage, protein degradation rate and estimated escape were similar for intact alfalfa hay (0.103/h and 43%) and silage (0.067/h and 43%). This result might be explained by the less efficient microbial utilization of silage NPN, greater protozoal numbers on hay, greater soluble true protein in hay, or differences in molecular mass and stability of soluble proteins in hay versus silage. Use of a two-compartment model, based on water-soluble and insoluble CP fractions assumed to pass with the liquid and solid phases, respectively, yielded RUP estimates for alfalfa hay and silage that were similar to NRC estimates.
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Affiliation(s)
- V D Peltekova
- Agricultural Research Service, USDA, US Dairy Forage Research Center, Madison, WI 53706, USA
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Abstract
Two experiments were conducted to determine the relationship between enzymatic digestion of forage protein and fractionation based on solubility. The first experiment used 42 forages, each replicated three times, including different species, stages of maturity, and methods of conservation. Crude protein was fractionated into six parts for each forage by sequential extraction in TCA, bicarbonate-phosphate buffer, acetone, detergent at pH 7, and detergent with acid. Multiple regression analysis, with all the solubility fractions as independent variables, resulted in prediction of CP degradation by ruminal enzyme extract at 2 and 24 h; R2 were .88 and .81, respectively. Greater solubility in the buffer and the detergent at pH 7 was associated with higher protein degradation; solubility in acetone, detergent with acid, and insolubility were associated with lower degradation. In the second experiment, eight forages each replicated twice were digested with ruminal enzyme for 0, 2, 6, and 24 h and then were extracted as described. Solubility in TCA and acetone increased during degradation, but solubility in buffer, detergent with acid, and insolubility decreased. For both experiments, buffer-soluble CP was the only uniform fraction across forages; other fractions contained proteins that degraded at diverse rates. Solubility of CP is related to degradation properties, but further research is needed to improve the accuracy of predictions based on solubility.
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Affiliation(s)
- R A Kohn
- Department of Animal Science, Michigan State University, East Lansing 48824, USA
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Weiss WP. Full lactation response of cows fed diets with different sources and amounts of fiber and ruminal degradable protein. J Dairy Sci 1995; 78:1802-14. [PMID: 8786264 DOI: 10.3168/jds.s0022-0302(95)76805-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Twenty Holstein cows were fed diets based on a mix of haycrop silage (immature orchardgrass or immature alfalfa) and corn silage with a conventional concentrate (primarily ground ear corn and soybean meal) or a concentrate based on by-products (primarily soyhulls, fish meal, and corn gluten meal). Diets for periods 1 (7 to 134 DIM), 2 (135 to 234 DIM), and 3 (235 to 305 DIM) were 40:10:50, 40:20:40, and 40:30:30 haycrop silage:corn silage:concentrate (DM basis), respectively. Dietary NDF ranged from 33 to 45%. The species of haycrop forage fed in combination with corn silage did not greatly affect milk production (mean = 28 kg/d), milk composition, nutrient digestibility, or DMI (expressed on a BW basis). Cows fed alfalfa gained more BW than those fed orchardgrass (.18 vs. .03 kg/d). Cows fed by-products produced similar amounts of milk, more milk fat (1.1 vs. .9 kg/d), and had higher DMI (21.4 vs. 19.6 kg/d) but lower BW gains (.03 vs. .18 kd/d) than those fed conventional concentrate. These data showed that a mix of high quality orchardgrass and corn silage is acceptable for dairy cows and that supplementation strategies are similar for diets based on orchardgrass and those based on alfalfa.
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Affiliation(s)
- W P Weiss
- Department of Dairy Science, Ohio Agricultural Research and Development Center, Ohio State University, Wooster 44691, USA
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Kohn RA, Allen MS. Effect of plant maturity and preservation method on in vitro protein degradation of forages. J Dairy Sci 1995; 78:1544-51. [PMID: 7593847 DOI: 10.3168/jds.s0022-0302(95)76776-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The influence of maturity and method of conservation on protein degradation was determined for four different forage species. Alfalfa, smooth bromegrass, and reed canarygrass were harvested at three maturities, and whole plant corn was harvested at two maturities. Samples of each forage were freeze-dried or wilted and then ensiled in mini silos at two DM contents. Additional samples of all forages except corn were field-dried to hay. Ground sample was incubated for 0, 2, and 24 h with crude enzyme extract from ruminal contents. Degraded protein as a percentage of total CP was determined as the amount of protein that was soluble in TCA (80 g/L) after degradation. Increased maturity resulted in lower protein degradation for alfalfa, bromegrass, and canarygrass. For example, the most mature alfalfa or bromegrass, respectively, had 77 or 63% as much N that was soluble in TCA after 2 h of incubation with ruminal enzyme than the least mature forage of the same species. Although protein degradation was higher for ensiled than for dried forage, silage DM content had no consistent effect. Freeze-dried material generally had less degraded protein than hay, but protein degradation of bromegrass at 24 h was lower for hay than for freeze-dried samples. Protein degradation of forages was highly variable and depended on plant maturity and conservation method.
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Affiliation(s)
- R A Kohn
- Department of Animal Science, Michigan State University, East Lansing 48824, USA
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Use of electrophoresis to quantify ruminal degradability of protein from concentrate feeds. Anim Feed Sci Technol 1994. [DOI: 10.1016/0377-8401(94)90078-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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