The influence of fiber content of hay (low-fiber 47% NDF and high-fiber 62% NDF of DM) and concentrate level (high 50% and low 20% of ration DM) on chewing activity, passage rate and nutrient digestibility were tested on four restrict-fed (11.1 to 13.7 kg DM/d) Holstein cows in late lactation. Aspects of ruminal fermentation and digesta particle size distribution were also investigated on two r...

We used six ruminally cannulated Texel wethers to study the relative role of protozoa and lactate-metabolizing bacteria in ruminal fermentative patterns during an induced latent acidosis. The sheep were fed an alfalfa hay diet (H) and latent acidosis was induced, following a short transition period of one week, with a grain-rich acidotic diet (W, 60% wheat + 40% alfalfa hay). Ruminal pH, rumina...

Story in Brief The phosphorus concentration in ruminal fluid was determined for steers limit-fed rations with phosphorus concentrations ranging from .06 to .17 percent. Ruminal phosphorus concentration was increased with phosphorus intake at dietary concentrations below .12 percent for steers. This relationship was employed to estimate the ruminal availability of phosphorus from four phosphorus...

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...

An in vitro gas production technique was used to evaluate the effects of different adsorbents on the gas production parameters of lead-exposed diet. Ruminal fluid, obtained from fistulated sheep (3-4 years of age and 40±5 kg BW), and experimental diets samples, 200 ± 0.2 mg DM, were incubated in 100 mL glass bottles. To each bottle, one of the following treatments was applied: 1) control (no Pb...

Four ruminal cannulated Texel wethers were used to study the long-term effects of an acidotic diet on ruminal parameters and blood acid-base status. The short-term events around feeding and the recovery of the animals were followed after this nutritional disturbance. Sheep were limit-fed consecutively a control diet H (100% hay) (one week), an acidotic diet W (60% wheat + 40% hay) (2 weeks), an...

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,...