1973 Volume 19 Issue 4 Pages 305-315
Various factors influencing the life of rumen protozoa, Entodinium species, were studied.
Optimal conditions for entodinial survival were determined for the following factors: Temperature, 38-40°; pH, 6.0-7.0; redox potential, -250 to -400mV; osmotic pressure, 0.7-1.0% NaCl equivalent. The influence of various compounds formed by rumen microorganisms was examined and toxic levels were found; ammonia had a harmful effect on the protozoa above the level of 3mmol/100ml; methylamine, histamine, and formate above 10mmol/100ml; methanol and ethanol above 30mmol/100ml. Acetate, propionate, butyrate, and lactate had no deleterious effect within the limits tested. In addition, the influence of antibiotics is described.