Mature Angus steers were intraruminally infused with base to increase ruminal pH. Base infusions, increasing rumen pH from 5.8 to 6.2, did not change duodenal pH but tended to reduce fecal pH. Increased ruminal pH tended to increase digestion of fiber (9 percent) but reduced ruminal digestion of starch by 18 percent (P> .05). Ruminal pH and ruminal starch digestion were negatively correlated (P...

To determine the effects of different sources of fiber and feeding frequency on digesta water-holding capacity (WHC; g H2O/g DM) and ruminal liquid contents, four ruminally fistulated Jersey steers were fed a 60:40 roughage-concentrate diet at 1.5 times NEm. Diets contained either sorghum silage (SS) or a 67:33 mixture of SS and soyhulls (SH) as roughage and were fed either once or 12 times dai...

Beef cattle have been fed ionophores and other antibiotics for more than 20 years to decrease ruminal fermentation losses (e.g methane and ammonia) and increase feed efficiency, and these improvements have been explained by an inhibition of gram-positive ruminal bacteria. Ionophores are not used to treat human disease, but there has been an increased perception that antibiotics should not be us...

Diaryliodonium chemicals increased nitrogen (N) absorption, utilization of absorbed N and N retention in growing steers. Fifty parts per million of the chemicals (diphenyliodonium chloride, diphenyliodonium bromide, 4,4'-difluorodiphenyliodonium chloride or 4,4'-dimethyldiphenyliodonium chloride) in the diet appeared sufficient to promote significant (P less than .05 or .10) improvements in N u...

The objective of this experiment was to determine the respective effects of level of intake and of the amount of volatile fatty acids (VFAs) present in the rumen on VFA ruminal absorption. In a factorial design, six ewes received a hay diet either at 126 or at 73% of energy maintenance requirements. Their capacity of absorption of VFAs was evaluated by the method of temporarily isolated rumens,...

A quantitative method of analysis for 2-aminoethylphosphonic acid (AEP) was developed using reverse-phase HPLC. The detection limit for AEP was 15 nM, and the detector response (peak area) was linear from AEP levels up to 100 microM (R = .99). Mean recovery of AEP added to strained ruminal fluid from faunated sheep was 98.2%. When AEP was added to a fermentation mixture at a concentration of 22...

Five in situ trials with whole-plant corn silage (WPCS) were conducted in two ruminallycannulated Holstein cows to determine 24-h ruminal disappearance of dry matter (DM), starch, and neutral detergent ®ber (NDF). In Trial 1, the effect of maturity of WPCS on ruminal nutrient disappearance was evaluated. Treatments were early dent (ED), 1/4 milk-line (1/4 ML), 2/3 milkline (2/3 ML), and black-l...

The established calculation of ruminal extent of degradation using the polyester bag method overestimates extent. The wash fraction, at least in part, is subject to losses from the rumen due to passage. Four formulae are proposed to minimize this risk of overestimation. Four options are considered: 1) passage losses for particulate matter escaping from the bag at zero time are according to the ...