Passage of protozoa and volatile fatty acids from the rumen of the sheep and from a continuous in vitro fermentation system

Abstract

I . A procedure for sampling digesta from within the omasal canal of sheep given a variety of roughage diets was used to enable comparison to be made of the composition of effluent from the reticulo-rumen with that of rumen fluid.2. Concentrations of protozoa in effluents, relative to a soluble marker continuously infused intraruminally, were usually less than 20 yo of corresponding rumen fluid concentrations. It was estimated that the amount of protozoal nitrogen leaving the rumen represented less than 2% of dietary N.3. Passage of volatile fatty acids (VFA) from the rumen in effluent was less than 75% of that indicated by rumen concentrations.4. A continuous, in vitro fermentation system was developed, in which outputs of protozoa were comparable with in vivo outputs.

Effect of defaunation on protein and fibre digestion in sheep fed on ammonia-treated straw-based diets with or without maize

“…Compared with diet S, maize supplementation increased the microbial-N flow in the small intestine only in defaunated sheep. With the starch-supplemented diet, the number of protozoa increased ; the absence of effect noted on the microbial-N flow in the duodenum of faunated animals can be explained by the selective retention of protozoa in the rumen and by recycling of their N (Weller & Pilgrim, 1974;Harrison & McAllan, 1980;Leng, 1982). The low contribution of protozoal N in the duodenal-N flow only compensated for the decrease in bacterial N generally observed after inoculation of protozoa in a defaunated rumen .…”

Effect of Lignosulfonate on Rumen Microbial Degradation of Soybean Meal Protein in Continuous Culture

“…Liquid dilution rate and solids dilution rate were maintained at 0.10 h ' and 0.05 h ', respectively, while culture pH was 6.3 -f 0.05. The infusion buffer was that of Weller and Pilgrim (1974) …”

Factors Affecting the Uptake and Metabolism of Soluble Carbohydrates by the Rumen Ciliate Dasytricha ruminantium Isolated from Ovine Rumen Contents by Filtration

“…The carbohydrate and protein made available to the host depend on the rate of wash-out from the rumen. Weller & Pilgrim (1974) suggest that there may be considerable sequestration of protozoa in the rumen. This, with the results obtained above, lends support to the suggestion of Heald (1951) that Dasytricha polysaccharide makes little contribution to the total carbohydrate available to the host.…”