1. The contribution of dietary constituents to the large urinary output of benzoic acid characteristic of ruminants and some herbivores is not well understood. 2. Methods for the analysis of quinic, cyclohexanecarboxylic, benzoic, phenylacetic, 3-phenylpropionic and cinnamic acids in urine and in rumen fluids were developed. 3. The urinary output of aromatic acids by sheep given seven-rations w...

A single injection of 15 g NaCl into the rumen, which increased the osmotic pressure of rumen fluid from 369 to 474 mOsmol/kg, resulted in a decrease in the transfer of blood urea into rumen fluid from 2.3 to 1.6 g N/day in sheep fed 50 g of chaffed oaten hay every hour. It is concluded that the reduced urea transfer was the result of a reduced urea input via saliva. The rumen wall remained vir...

this study was conducted to determine in vitro crude protein degradation (ivdp) parameters and effective crude protein degradability (epd) of various feeds using the modified in vitro gas production (gp) technique. feed samples were alfalfa hay, soybean meal, soybean, rapeseed meal, sunflower meal and fish meal. rumen fluid was collected before the morning feeding from four rumen fistulated lam...

1. Experiments were undertaken to examine the kinetics of large ciliate protozoa in the rumen of cattle on sugar-cane diets. 2. Three Zebu bulls were fed once daily on a diet of sugar cane and wheat bran. The diurnal patterns of volatile fatty acids and ammonia concentrations, and the numbers of protozoa in rumen fluid were determined. The numbers of protozoa reached values of 5 X 10(4)/ml for ...

Feeding dairy cows diets high in easily degradable carbohydrates increases the incidence of rumen and systemic metabolic disorders; however, the triggering factor is not well understood. In this study, dairy cows were fed 4 different amounts of barley grain-based concentrate at 15, 30, 45, and 60% (dry matter basis) of a total mixed ration to determine whether alterations in the rumen environme...

1. Four sheep, each fitted with a rumen fistula and a re-entrant cannula at the proximal duodenum were fed a semi-purified diet containing urea as the only nitrogen source. The quantities of total protozoal amino acid-N (TPAN) present in the rumen and entering the duodenum were determined when the mean rumen dilution rate (D) was low (0.034/h) and when D was increased to 0.078/h by the intrarum...

Two rumen protozoa vaccine formulations containing either whole fixed Entodinium or mixed rumen protozoa cells were tested on Merino sheep with the aim of decreasing the number and/or activity of protozoa in the rumen. Negative control (no antigen) and positive control (Tetrahymena corlissi antigens) treatments were also included in the experiment. Blood and saliva were sampled to measure the s...

Ruminant species differ in the degree that their rumen contents are stratified but are similar insofar that only very fine particles are passed from the forestomach to the lower digestive tract. We investigated the passage kinetics of fluid and particle markers (2, 10 and 20 mm) in fistulated cattle (Bos primigenius f. taurus), muskoxen (Ovibos moschatus), reindeer (Rangifer tarandus) and moose...

In this study, nine male Dallagh sheep (initial weight 35±2 kg) were used in a replicated 3 × 3 latin square design experiment with three treatments and three 21-day periods (14 d adaptation, 7 d collection). Treatments were control (without addition) and two treatment diets containing 10% dry matter Glycyrrhiza glabra (licorice) and Urtica dioica (nettle) powder. The dry matt...

All mechanistic rumen models cover the main drivers of variation in rumen function, which are feed intake, the differences between feedstuffs and feeds in their intrinsic rumen degradation characteristics, and fractional outflow rate of fluid and particulate matter. Dynamic modeling approaches are best suited to the prediction of more nuanced responses in rumen metabolism, and represent the dyn...