ADF Degradability Research Articles

IN SITU DEGRADATION OF PRICKLY PEAR (OPUNTIA SPP) TREATED WITH YEAST AND AMMONIUM SULFATE

Prickly pear (Opuntia spp) is a forage resource of great importance in arid and semiarid lands of Northern Mexico during winter time. Because of severe freeze and abscence of precipitation, disponibility of good quality forage is scarce, raising costs of animal feeding. The main objective of this study was to determine in situ degradation of three prickly pear genotypes (Opuntia spp) with and without additives (yeast 10% and ammonium sulfate 20%) through 8 time intervals, using dacron bags incubated in the rumen of fistulated cows. Higher degradation of dry matter (ISDDM) of prickly pear without additives was observed in AN-TV6 genotype, in all time intervals. AN-FV1 showed intermedia values, and ecotype Liebres showed the lower values; with additives, AN-FV1 showed greater degradation with 80%, with respect to control, genotype AN-TV6 showed lower degradation since 12 hour time and ecotype Liebres showed the lower degradation, with 70%. Crude protein degradation (DCP), of ecotype Liebres without additives showed greater degradation in the first 12 hours, meanwhile AN-TV6 with additive in 24 and 28 hours showed the higher values, with 89 and 94%, respectively. All treatments at 72 hour incubation time showed 100% of protein degradation. Acid detergent fiber degradation values (ADFD), of genotypes AN-TV6 and AN-FV1 without additive, showed the higher values, 90 and 88%, respectively. At period end, meanwhile with additives, shown degradation values of 74 and 70%; Liebres ecotype showed the lower values, with and without additives, with a degradation of 63%.

Chemical composition, ruminal kinetic parameters, and nutrient digestibility of ammonia treated oat hulls

A study was conducted to determine the effects of ammoniation (3 or 5% by dry weight) on the nutritive value of oat hulls. Ruminal nutrient kinetic parameters and degradability of untreated and ammoniated oat hulls were determined using two non-lactating cows fitted with rumen cannulas. Eighteen steers were used in a digestibility trial to determine nutrient utilization of three diets consisting of 100% barley silage, 50% untreated oat hulls plus 50% barley silage, and 50% ammoniated oat hulls plus 50% barley silage (DM basis). Ammoniation at both levels increased (P < 0.05) total N and reduced (P < 0.05) neutral detergent fibre levels of oat hulls. Most of the N added due to ammoniation was in the form of non-protein N. The results of the in situ trial showed that ammoniation at the 3% level increased the potentially degradable NDF and ADF fractions as well as their rates of degradation. Ammoniation at the 3% level improved (P < 0.05) effective ruminal degradability of NDF and ADF of oat hulls by 41 and 35%, respectively. Dry matter intake was highest (P < 0.05) for steers fed the ammoniated oat hull diets, intermediate for those fed the untreated oat hull diets and lowest (P < 0.05) for those fed the 100% barley silage diet. Steers fed the ammoniated oat hull diet had higher (P < 0.05) total tract digestibility of NDF and lignin relative to steers fed the untreated oat hull diet. However, total tract digestibility of dry matter was not affected by ammoniation. It was concluded that ammoniation is a viable method for improving the feeding value of oat hulls to ruminant animals. Relative to the 3% level, ammoniation at 5% resulted in a marginal improvement in the nutritive value of oat hulls. Key words: Ammonia treatment, oat hulls, ruminal degradation, nutrient utilization

Effect of Dietary Structural to Nonstructural Carbohydrate Ratio on Rumen Degradability and Digestibility of Fiber Fractions of Wheat Straw in Sheep

The effect of different dietary structural carbohydrate (SC) to nonstructural carbohydrate (NSC) ratios on fiber degradation, digestion, flow, apparent digestibility and rumen fluid characteristics was studied with a design using 18 wethers fitted with permanent rumen and duodenum cannulae. All sheep were divided into six groups randomly, receiving six diets with varying SC to NSC ratios. All diets contained the same proportion of wheat straw and concentrate. The dietary SC to NSC ratios were adjusted by adding cornstarch to the concentrate supplements. The duodenal and fecal flows of dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose (HC) and cellulose (CEL) were estimated using chromium-mordanted wheat straw as a flow marker. The degradation parameters of wheat straw DM, NDF, ADF, HC and CEL were determined by incubating the ground wheat straw in nylon bags in the rumen for different periods of time. There was no effect (p>0.05) of the different dietary SC to NSC ratios on rumen pH or NH3-N, but acetate, propionate and butyrate concentrations were significantly affected (p<0.05 or p<0.01) by dietary SC to NSC ratios in the rumen fluid. When the dietary SC to NSC ratio was 2.86, the highest rumen degradability of wheat straw DM, NDF, ADF and CEL was found, but the highest apparent rumen digestibilities of DM, NDF, ADF, HC and CEL occurred at a 2.64 SC to NSC ratio. However, because of compensatory digestion in the hindgut, the apparent digestibilities of DM, NDF, ADF, HC and CEL were highest when the dietary SC to NSC ratio was 2.40. In conclusion, there is a optimal range of dietary SC to NSC ratios (between 2.86 and 2.40) that is beneficial to maximize wheat straw fiber degradation and apparent digestibility. (Asian-Aust. J. Anim. Sci. 2002. Vol 15, No. 11 : 1591-1598)

Ruminal degradability of alfalfa and corn after processing or maceration

The effects of mechanical treatment on ruminal degradability of alfalfa and corn were determined in three experiments using nylon bags incubated in the rumen of two fistulated dry cows. The first experiment was a 2 × 2 × 2 factorial design applied to chopped alfalfa at two levels of mechanical treatment (processing with two corrugated rolls in a forage harvester or no processing), two throughput rates (medium or high) and two moisture contents (after a 4-h or a 24-h field wilting period prior to processing). The second experiment was a 2 × 2 factorial design applied to chopped corn at two levels of mechanical treatment (processed or not) and two throughput rates (medium or high). In these two experiments, forages were immediately frozen (not fermented) for later degradability measurements. In the third experiment, alfalfa was mowed either with a conventional mower-windrower or an experimental mower-macerator with three corrugated rolls. After 40 h of field wilting, alfalfa was dehydrated and processed into pellets. In the first experiment (chopped and frozen alfalfa), throughput, processing and wilting period had no effect (P &gt; 0.05) on the effective degradability of DM, CP, NDF and ADF. In the second experiment, DM degradability of chopped corn decreased with an increased throughput (46.4% vs. 43.7%) but increased with processing (43.9% vs. 46.2%). Processing also increased CP degradability of corn. In the third experiment, maceration with subsequent field wilting during 40 h and dehydration produced alfalfa pellets with a higher degradability of DM (56.0% vs. 50.4%) and of NDF (27.1% vs. 17.3%) than pellets from non-macerated alfalfa. These results suggest that the increase in ruminal degradability is greater with alfalfa macerated and wilted in the field (exp. 3) than with alfalfa frozen immediately after harvesting and processing (exp. 1). Maceration probably reduced the loss of nutrients by decreasing field respiration. Processing of corn may have increased the ruminal degradability because of increased kernel breakage that facilitated starch digestion. Key words: Maceration, crop processing, ruminal degradability, alfalfa, corn

Comparison of Protozoal Populations and Digestion Rates Between Water Buffalo and Cattle Fed an All Forage Diet

Franzolin, R. and Dehority, B.A. 1999. Camparison of protozoal populations and digestion rates between water buffalo and cattle fed an all forage diet. J. Appl. Anim. Res., 16: 33–46. Water buffalo and cattle, with ad libitum access to chopped fresh tropical grass, had their rumen contents cross inoculated at three and five weeks after starting on the grass diet. Overall, eight samples of rumen contents were taken during a 17 week experimental period. Total protozoal concentrations and percentage of Diplodiniinae were higher in water buffalo, while percentage of Entodinium was lower. Rumen pH was not different between animal species; however, turnover rate was faster and rumen volume lower in water buffalo. The number of protozoal species in the family Isotrichidae and subfamilies Diplodiniiiiae and Ophryoscolecinae was much higher in water buffalo. Ten additional species of these protozoa became established in cattle after cross inoculation with water buffalo. Only two species from cattle were transfaunated into the. water buffalo. Entodinium species were identified only to the genus level. There were no differences between animal species either in the extent or kinetics of in situ degradability of DM, CP or ADF.

Effect of a Saccharomyces cerevisiae Culture on Nutrient Digestion in Lactating Dairy Cows

The digestive effects of a Saccharomyces cerevisiae culture were investigated. Four cows in early lactation that were fitted with ruminal and duodenal cannulas were used in a crossover design. The diet, which consisted of 60% corn silage and 40% concentrates, was supplemented or not supplemented with a daily dose of 50g of premix containing 0.5g of S. cerevisiae (6×108 cfu/g of premix). Total and ruminal digestibilities of organic matter, duodenal flows of nonmicrobial and microbial N, solid and liquid turnover rates, ruminal protozoal numbers, pH, ammonia N and volatile fatty acid concentrations, and concentrations of some plasma metabolites were not modified by the addition of S. cerevisiae. Ruminal dry matter content increased when S. cerevisiae was supplemented to the diet. In situ ruminal degradabilities of dry matter and neutral detergent fiber from corn stalk and of N from soybean meal were not modified; degradability of acid detergent fiber from corn stalk increased (32.5% vs. 26.3%) with the addition of S. cerevisiae. A short-term increase in N degradation was observed after 4 and 8h of incubation. This experiment showed no effect of S. cerevisiae on most quantitative digestive events; however, a positive transitory postprandial effect on some parameters of microbial activity was observed.

Evaluation of wheat-based wet distillers' grains for feedlot cattle

This study was conducted to determine the nutritive value of wheat-based wet distillers' grains (WDG) for ruminants. Chemical composition and in situ rumen degradability characteristics of WDG were compared with wet brewers' grain (WBG). The in situ trial involved three 48 h incubations utilizing one ruminally fistulated cow. Trail 2 compared the value of WDG in growing and finishing rations relative to WBG and a control based on standard feed ingredients. Relative to WBG, WDG had greater (P &lt; 0.05) NDF and ADL and similar ADF and CP levels. Fractionation of CP indicated that WDG contained more (P &lt; 0.05) neutral detergent and less acid detergent insoluble CP than WBG. Effective degradability of DM, CP, NDF and ADF in WDG exceeded (P &lt; 0.05) WBG. Animal performance in the growing period was similar (P &gt; 0.01) among treatments. During the finishing period the control fed steers grew faster (P &lt; 0.05) than WBG fed steers. WDG fed steers exhibited more (P &lt; 0.05) intermuscular fat than control or WBG fed steers and less (P &lt; 0.05) subcutaneous fat than WBG fed steers. It was concluded that WDG is more degradable than WBG and thus cannot be considered as good a source of rumen undegraded protein. WDG can be used effectively as an energy and protein source for growing and finishing cattle. Key words: distillers' grains (wet), brewers' grains (wet), rumen degradability, cattle, gain, carcass

Degradação da proteína e fibra do caroço de algodão integral (Gossypium hirsutum L.) no rúmen

0 experimento teve como objetivo avaliar a degradabilidade “in situ” da matéria seca (MS), proteína bruta (PB) e fibra em detergente ácido (FDA) do caroço de algodão integral (CAI) em substituição ao farelo de algodão, empregando-se silagem de sorgo (SS), como único volumoso. Além disso, avaliaram-se as alterações no pH e cinética de fermentação ruminal de 9 bovinos, machos, com fístulas no rúmen. Os tratamentos foram: A = 0% CAI, B = 6,6% CAI e C = 15% CAI; a silagem de sorgo entrou na proporção de 70% em todos os tratamentos. As rações eram isonitrogenadas, com aproximadamente 12% de PB na MS. Houve diferença estatística (p &lt; 0,05) para a degradação de MS no tempo 48 horas (A = 54,4%; B = 54,2% e C = 58,7%), de PB às 12 horas (A = 40,3%; B = 47,7%; e C = 53,1%) e de FDA às 48 horas (A = 40,3%; B = 41,2% e C = 45,6%), ocorrendo maiores taxas de degradação com oaumento do nível de CAI na dieta. Os demais parâmetros (volume ruminal, “turn over" do digesto ruminal e pH do conteúdo ruminal) não mostraram diferenças significativas entre tratamentos. O emprego crescente de CAI, até 15% da MS da ração, aumentou a degradação da MS, da PB e da FDA desse produto.

Chemical characterization and nutrient availability of high and low fiber canola meal

Tail-end dehulling separates regular canola meal (CM) into low (LFCM) and high (HFCM) fiber fractions. The study was designed to study the effects of tail-end dehulling of CM on the chemical composition, ruminal nutrient degradability, and intestinal protein availability of the resulting HFCM and LFCM fractions. Relative to LFCM and CM, HFCM had higher (P &lt; 0.05) neutral (NDF) and acid (ADF) detergent fiber and acid detergent lignin (ADL) levels. Canola meal had higher (P &lt; 0.05) ADF and ADL but not NDF relative to LFCM. Crude protein (CP) was lower (P &lt; 0.05) in HFCM than in CM and was lower (P &lt; 0.05) in CM than in LFCM. Neutral and acid detergent insoluble CP followed the pattern of NDF and ADF, respectively. Protein fractionation showed no difference in non-protein nitrogen between the three meals. True protein was lower (P &lt; 0.05) in HFCM than CM and LFCM. Sub-fractionation of true protein resulted in a B1 fraction of 148, 145, and 129 g kg−1 for CM, LFCM and HFCM, respectively. Respective values for B2 and B3 fractions were 768, 769, and 751 g kg−1 and 84, 86, and 120 g kg−1. Results indicated that ruminal effective degradability of dry matter and ADF was lower (P &lt; 0.05) in HFCM relative to CM and was lower in CP relative to LFCM. Ruminal effective degradability of CP and NDF was lower in HFCM than in CM and LFCM. No differences were observed between CM and LFCM. Intestinal digestibility of rumen undegraded protein was higher (P &lt; 0.05) in LFCM than in CM and was higher (P &lt; 0.05) in CM than in LFCM. It was concluded that tail-end dehulling of canola meal resulted in a LFCM with higher protein and lower NDF and ADF content and improved nutrient availability and a HFCM with a lower protein and a higher fiber (particularly ADF) content and reduced nutrient availability. Further studies are required to determine the effect of feeding HFCM on ruminant performance. Key words: High fiber, low fiber, canola meal, chemical composition, ruminal degradability

Effects of underfeeding and of fish meal supplementation on forage digestion in sheep

SUMMARYThe effects of severe food restriction and of protein supplementation on the apparent digestibility of a forage were studied on 12 wethers in 1992 at INRA, Theix. Ruminal digestion of the forage cell walls was studied in a second experiment carried out on four ewes fitted with rumen and duodenal cannulas, receiving the same diets as the wethers. The animals were fed on two different hay-based diets: hay only (58 or 25 g/kg BW0·75 per day) or hay supplemented with fish meal (48 or 20 g hay with 6·5 and 3·0 g fish meal respectively per kg BW0·75). The effects of fish meal supplementation on apparent digestibility of the hay cell walls were small, + 1·8 and + 2·3 units for neutral detergent fibre (NDF) and acid detergent fibre (ADF) respectively. In contrast, NDF and ADF digestibility was respectively 4·0 and 4·7 units higher at low than at high intake. Rumen fluid volume decreased by 2·4 1 with decreasing intake, while water concentration in rumen content increased slightly from 89·8 to 91·8%. The mean retention time of the hay particles in the foreguts increased concomitantly from 39·5 to 55·1 h. This was achieved by a higher retention time to a similar extent in both slow and fast compartments. The calculated in situ degradability of NDF and ADF increased respectively by 12·1 and 13·1 units with decreasing intake. This reflected the lower fractional outflow rate recorded at low intake. If a fractional outflow rate value of 4·1%/h (as measured in high intake diets) was applied to all dietary treatments, NDF and ADF in situ degradability would be greater at low than at high intake (31·7 v. 26·6% for NDF; 27·9 v. 22·1 % for ADF), indicating a higher microbial activity in restricted diets. Interactions between intake and fish meal supply were detected for in situ degradation parameters, indicating principally a reduction of the cell wall undegraded fraction in supplemented diets when intake declined. Ruminal fermentation was modified by the dietary treatments, the acetate: propionate ratio being higher at low intake. Fish meal increased concentrations of ammonia and of isoacids in rumen liquid. The relationship between apparent digestibility and in situ degradability of plant particles is discussed.

Intake, Digestibility, and Ruminal Degradability of Shredded Hay

Thirty-two Outaouais intact male lambs averaging 39.1kg were assigned randomly to a 2 × 2 factorial arrangement of treatments consisting of two forages and two methods of harvesting to determine intake and digestibility. The four treatments fed during the experiment consisted of alfalfa and timothy hays harvested with either a prototype mat maker or a conventional mower conditioner. Hays were fed for ad libitum intake for the entire experiment, and data on digestibility and intake were collected for 9 d after a 21-d adaptation. Ruminal degradability of DM, N, and ADF of hays was estimated with two fistulated cows using nylon bags incubated up to 96h. Harvesting with the prototype mat maker compared with the conventional mower generally increased intake and digestibility of alfalfa and timothy hays. Ruminal degradability of DM and the potentially degradable fraction of DM and ADF was higher when hay was harvested with the prototype mat maker than with the conventional mower. The increased digestibility of hay harvested with the prototype mat maker could be explained by the increased digestibility in the rumen because harvesting with the prototype mat maker increased the potentially degradable fraction of DM and ADF. These results suggest that the digestible energy content of hay was increased by shredding.

Effects of different forms of polyunsaturated fatty acids on rumen fermentation and total nutrient digestibility of sheep fed prairie hay based diets

Four rumen cannulated sheep were used in a 4 × 4 Latin square design to investigate the effects of soy fatty acid infusion on ruminal fermentation, in sacco digestion and apparent total digestibility. The control diet (C) based on 78.0% prairie hay, 5.3% protein supplement and 16.7% whole barley, was compared to diets where soy oil (SO), emulsified soy oil (ESO) or calcium salts of soy oil fatty acids (CaSSO) replaced whole barley. Diets were formulated to be isonitrogenous and isoenergetic. Fat content in DM was 2.9% for diet C, 8.3 to 9.0% for supplemented diets. In sacco degradation of DM, ADF and NDF was not affected by lipid infusions during the first 24 h in the rumen. Total VFA and molar proportion of butyrate in prefeeding rumen fluid were lower with the SO diet compared with diet C: 53.3 vs. 81.6 mmol/1 and 10.7 vs. 14.8%, respectively. Adding SO or ESO depressed apparent digestibilities of OM, ADF and NDF by 8.8 to 9.0%; depression of fiber digestion was reversed with diet CaSSO. Fat infusion increased total dietary lipid digestibility particularly with emulsifiers, 60.0, 73.9, 81.5 and 68.3% for diets C, SO, ESO and CaSSO, respectively. Calcium salts of polyunsaturated fatty acids were an effective energy source for ruminant rations.

Effect of extruding on ruminal disappearance and lower gastrointestinal tract digestion of white lupin seeds

The effect of extruding white lupin (Lupinus albus 'Lublanc') seeds (WLS) at 110, 130, 150 or 180 °C on the in vitro solubility of crude protein (CP) and in sacco rumen degradation and intestinal digestion of rumen escape CP and fiber was determined. Rumen degradation was estimated by incubating nylon bags in the rumen of cows for 2, 4, 8, 16, 24 and 48 h. Extruding WLS at 110, 130, 150 and 180 °C reduced the CP-solubility by 32.8, 47.7, 58.4 and 67.5%, respectively. The effective ruminal degradabilities of CP, acid detergent fiber (ADF) and neutral detergent fiber (NDF) were evaluated assuming a ruminal outflow rate of 0.06 h−1. Heating WLS at 110, 130, 150 and 180 °C decreased the ruminal degradability of CP value: 89.8, 79.9, 65.1, 61.8 vs. 93.4% (raw), respectively; the corresponding values for ADF and NDF were: 38.4, 35.3, 34.2, 27.6 vs. 43.6% (raw) and 37.7, 33.1, 32.2, 26.5 vs. 39.4% (raw). Postruminal digestion was estimated using a sequence of ruminal in situ incubation for 4, 8 and 16 h, in vitro incubation in an acid-pepsin bath for 3 h and a mobile nylon bag technique distal to the abomasum. Extrusion of WLS decreased the degradability of CP, ADF and NDF in the rumen with a corresponding increase in the amounts digested in the postruminal sections; the whole-tract digestibility was generally unchanged. Therefore, the processing shifted the digestion of these components from rumen to the lower gastrointestinal tract. Key words: White lupin seed, in vitro solubility, rumen degradability, postruminal digestion, crude protein, detergent fiber

Effect of protein-protected fat on ruminal and total nutrient digestibility of sheep diets.

Experiments were conducted to determine the effects of supplementing chopped ryegrass hay with 0, 5, 10, or 20% fat coated with ruminal bypass protein (Prolip on ruminal digestion by cows and nutrient digestibility by sheep. Ruminal disappearances of DM, ADF, and NDF were measured by the in sacco technique using a cannulated cow. Degradation of DM, ADF, and NDF was not affected by protected fat supplementation at the 5, 10, or 20% level during the first 16 h in the rumen. In addition, supplementation with Prolip did not influence in vitro fermentation characteristics such as pH and VFA patterns. A digestibility experiment with six mature sheep in a switch-back design showed no decrease in feed intake or other undesired effects between unsupplemented (basal) and Prolip-supplemented diets. Whatever the diet fed to sheep, fiber digestibility was similar; however, DM and nitrogen digestibilities were significantly higher relative to the basal diet when ryegrass hay was substituted at 20% (64.2 vs 59.0% and 74.1 vs 71.1%, respectively). Ether extract digestion was enhanced by increasing level of Prolip; the corresponding values were 48.0, 64.9, 74.6, and 84.6% at 0, 5, 10, or 20% Prolip. Likewise, Prolip supplementation at the 10 or 20% level augmented digestibility of energy (62.7 or 65.9 vs 59.2%). Nitrogen and energy retentions were improved due to the decreases in fecal and(or) urinary excretion(s).

Effect of Aspergillus oryzae Fermentation Extract (Amaferm®) on In Vitro Fiber Degradation

The influence of Aspergillus oryzae fermentation extract (Amaferm®) on in vitro fiber degradation was determined by incubating eight ground fibrous feedstuffs with rumen fluid and buffer inoculum. Amaferm® was added at 0, .4, .8, or 1.2g/L of fermentation mixture. Both NDF and ADF degradabilities were determined after 96h of incubation. Addition of extract had no effect on NDF or ADF degradability of pure cellulose, low endophyte fescue, wheat straw, corn silage, or prairie hay. Addition of Amaferm® at .8 or 1.2g/L increased NDF and ADF degradations of bromegrass hay and alfalfa hay; its addition at .4 or .8g/L, but not at 1.2g/L increased NDF and ADF degradation of high endophyte fescue hay. In a second set of in vitro fermentations, selective antimicrobials (penicillin, streptomycin, and cycloheximide) were used to assess the influence of Amaferm® on various microbial groups. The enhanced fiber degradation by Amaferm® was attributed to its stimulation of bacterial activity because its addition to whole rumen fluid without or with cycloheximide increased fiber digestion. In contrast, addition of Amaferm® to the whole rumen fluid plus penicillin and streptomycin treatment had no effect on fiber degradation, suggesting that fungal or protozoal activity was not affected by treatment. In conclusion, Amaferm® increased fiber digestibility of certain feedstuffs, and the increase was mediated via stimulation of rumen bacterial, but not fungal or protozoal activities.

Feed utilization of beef steers fed grass as hay or silage with or without nitrogen supplementation.

Six Hereford steers averaging 256 kg were used in a 2 x 3 factorial arrangement within a 6 x 6 Latin square design to study the effect of forage conservation (silage vs hay) and N supplementation (0, 200 g of fish meal plus 43 g of urea, or 400 g of fish meal) on ruminal characteristics, digestibility, blood urea, and in situ degradability of DM, N, and ADF. Dry matter intake of forage and total DMI did not differ among treatments (P greater than .05) and averaged 5.3 and 5.5 kg, respectively. Steers fed silage had greater (P less than .05) pH and concentrations of ammonia N, isobutyrate, isovalerate, and valerate in the rumen than in the rumen of those fed hay. Nitrogen supplementation increased (P less than .05) concentrations of total VFA and valerate in the rumen. Digestibility of N and ADF was greater (P less than .05) for silage than for hay, and N supplementation increased digestibility of N. Plasma urea concentrations were greater (P less than .05) for steers fed silage than for those fed hay. These data suggest that feed utilization is better with silage than with hay and is increased by N supplementation.

The delivery of cottonseed meal at three different time intervals to steers fed low-quality grass hay: effects on digestion and performance.

A ruminal fermentation trial and a steer growth trial were conducted to evaluate the effects of time interval of cottonseed meal (CSM) supplementation of predominantly meadow fescue grass hay (GH; CP = 6.6%) on nutrient digestion and growth performance of beef steers. The fermentation trial used four ruminally cannulated steers assigned to a 4 x 4 latin square design with dietary treatments of GH fed alone (C) or GH supplemented with 3 g CP/kg BW.75 daily as supplied by CSM every 12, 24 or 48 h. Nylon bags containing GH were inserted into the rumen on d 1 and 2 of each collection period and incubated for 12, 24, 48 and 96 h to measure NDF and ADF degradation. Subsequently, steers were fed Yb-labeled GH and fecal samples were collected to determine particulate passage rate (PR). Dry matter and NDF intake, mean NDF and ADF in situ disappearance and ruminal VFA concentrations were greater (P less than .05) when CSM was fed; however, the delivery of CSM at various times did not affect (P greater than .10) these variables. Supplemented diets tended (P = .08) to have faster PR compared with the C diet. In the growth trial, CSM supplemented steers consumed more digestible DM (P less than .05) and had greater (P less than .05) daily gain compared with C steers. Effects due to time of CSM supplementation were not observed for the variables measured in the present study.

Studies on the feeding value of agro-industrial by-products: Strategies for improving the utilisation of cocoa-pod-based diets by ruminants

Two treatment methods, forage supplementation and chemical treatment, both potentially capable of improving cocoa-pod utilisation by ruminants, were evaluated. Supplementation with Gliricidia sepium at 1.0% body weight of cattle fed on a 50% cocoa-pod diet yielded no positive results. Feed intake [4.6 vs. 4.8 kg dry matter (DM) day −1], growth rate (0.37 vs. 0.40 kg day −1) and feed/gain (12.7 vs. 12.0) for control and test cattle were similar. Chemical treatment using solutions of cocoa-pod ash (CPA), a caustic material, was more successful. Rumen degradability of cocoa-pods treated with CPA — equivalent in alkalinity to 2 (P 2), 4 (P 4), 6 (P 6) and 8 (P 8) g NaOH per 100 g — was linearly improved ( P > 0.05) with the DM, acid detergent fibre (ADF) and neutral detergent fibre (NDF) disappearance rates of samples treated with either NaOH or CPA of equivalent alkalinity being similar. Degradability of DM, ADF and NDF increased from 25, 12 and 7% (control) to 55, 44 and 45% for P 6- and 55, 46 and 42% for P 8-treated samples, respectively. Digestibility of DM in cocoa-pod-based diets also increased ( P > 0.05) from 45 (untreated) to 55% (P 8 treated) in sheep and to 60% in goats. Nevertheless, treatment with P 8 reduced ( P > 0.05) daily feed intake from 69 to 36 in sheep and from 48 to 42 g DM per kg W 0.75 in goats. Feed intake was, however, normal for diets containing P 6-treated cocoa-pods (67 and 61 g DM per kg W 0.75 per day) for sheep and goats, respectively. The concentration of CPA for treating cocoa-pod should, therefore, not be greater than the P 6 level (35 g per 100 g), which corresponds in alkalinity to 6 g NaOH per 100 g.

Effects of alkaline hydrogen peroxide treatment on in vitro degradation of cellulosic substrates by mixed ruminal microorganisms and Bacteroides succinogenes S85.

The effects of sodium hydroxide (NaOH) and alkaline hydrogen peroxide (AHP) treatments on wheat straw (WS) and various cellulosic substrates were determined by measuring susceptibility to degradation by mixed ruminal organisms or Bacteroides succinogenes S85. In vitro incubations were used to measure differences in fermentation resulting from each successive step in the AHP treatment process. In vitro incubations through 48 or 108 h were conducted to measure these differences. The AHP treatment of WS increased (P less than 0.05) dry matter, neutral detergent fiber, and acid detergent fiber degradation over control WS when these substrates were incubated with mixed ruminal microorganisms or B. succinogenes S85. Fermentations containing AHP-treated WS had greater (P less than 0.05) microbial purine (RNA) and volatile fatty acid concentrations by 12 h compared with those containing untreated or NaOH-treated WS. Xylose in AHP-treated WS was utilized more extensively (P less than 0.05) by 12 h compared with the xylose of untreated or NaOH-treated WS. Treatment with AHP removed 23% of the alkali-labile phenolic compounds from WS. When substrates with high levels of crystalline cellulose (raw cotton fiber, Solka floc, and Sigmacell-50) were treated with NaOH or AHP and incubated for 108 h with B. succinogenes S85, extent of acid detergent fiber degradation of cotton fiber and Sigmacell-50 was similar to that of their respective controls. Sodium hydroxide and AHP treatments were effective in increasing acid detergent fiber degradation of the Solka floc which contained, on average, 3.3 and 4.8 percentage units more acid detergent lignin and hemicellulose, respectively, than cotton fiber and Sigmacell-50.(ABSTRACT TRUNCATED AT 250 WORDS)