Using an in vitro incubation system containing undiluted ruminal contents from a steer fed a high-concentrate, corn-based diet, we examined microbial degradation of DL-alpha-tocopherol acetate (TA). Gas production, pH, and fermentation acid profiles were done in an initial experiment to ensure conditions for reproducible, viable cultures over 24 h. The pH decreased from 5.7 to 4.9, gas producti...

The objectives of this study were to examine the effects of feeding zinc-treated soybean meal (Zn-SBM) on ruminal fermentation patterns and duodenal AA flows in steers fed diets based on corn silage and corn. Six steers (385 kg) fitted with ruminal, duodenal, and ileal cannulas were used in a replicated 3 x 3 Latin square design experiment with 14-d periods. Diets were supplemented with solvent...

In vitro fermentations of pure cellulose by mixed ruminal microorganisms were conducted under conditions in which pH declined within ranges similar to those observed in the rumen. At low cellulose concentrations (12.5 g/L), the first-order rate constants (k) of cellulose disappearance were successively lower at initial pH values of 6.86, 6.56, and 6.02, but in each case the value of k was maint...

Sixteen ruminally cannulated, English-crossbred heifers (378 ± 28.4 kg) grazing small-grain pasture (SGP) were used in a completely randomized design to evaluate effects of supplementing different amounts of corn dried distillers grains with solubles (DDGS; 0, 0.2, 0.4, and 0.6% of BW; as-fed basis) on forage intake, digestibility, and rumen fermentation characteristics. The experiment was cond...

Six sheep fitted with ruminal fistulas were used in a repeated measurement design with two 24-d periods to investigate the effect of adding a specific mixture of essential oils (MEO) at 0 (control), 0.8 and 1.6 ml/d on apparent nutrient digestibility, rumen fermentation characteristics, rumen microbial population and blood chemical metabolites. Animals were fed with a 50:50 alfalfa hay: concent...

Binding of IgG antibodies to Entodinium spp. in the rumen of sheep (Ovis aries) was investigated by adding IgG, purified from plasma, directly into the rumen. Plasma IgG was sourced from sheep that had or had not been immunized with a vaccine containing whole fixed Entodinium spp. cells. Ruminal fluid was sampled approximately 2 h after each antibody dosing. Binding of protozoa by a specific an...

Two experiments were conducted to investigate the effects of a Saccharomyces cerevisiae fermentation product (XP, Diamond V, Cedar Rapids, IA) on in vitro ruminal fermentation of single forage and mixed diets. In Exp. 1, an in vitro test was used to determine the effects of various concentrations (0, 1, 2, and 3 g/L) of XP on ruminal fermentation of the major forage sources of China (rice straw...

The objective of this study was to determine the effects of organic acids and monensin on the in vitro fermentation of cracked corn by mixed ruminal microorganisms. Ruminal fluid was collected from a steer fed 36.3 kg of wheat silage and 4.5 kg of concentrate supplement once daily. Mixed ruminal microorganisms were incubated in anaerobic media that contained 20% (vol/vol) ruminal fluid and .4 g...

Our objective was to evaluate the effects of substituting feather meal (FM) for soybean meal (SBM) on ruminal fiber fermentation, lamb gain, blood metabolite profiles, and wool growth. A SBM supplement was formulated, and FM replaced either 33% (33FM), 66% (66FM), or 100% (FMS) of the SBM protein. Four ruminally cannulated wethers were used in a 4 x 4 Latin square design to study in situ rumina...