Studies on Alterations in the Rumen Fluid of Sheep, Especially Concerning the Microbial Composition, When Readily Available Carbohydrates are Added to the Food

Abstract

The feeding of lactose in excess to hay-fed sheep Ied to an acute acid indigestion with profound alterations in the microbial composition, pH and physical properties of the rumen fluid. The microbial changes were characterized by a transient rise in the amount of amylolytic streptococci succeeded by a rapid multiplication of lactobacilli with depression and destruction of the normal flora and fauna of the rumen. The acute indigestion was related to the lactobacillosis of the rumen. Parallel feeding experiments with sucrose led to indigestion with alterations in the rumen fluid similar to those induced by lactose but, as a rule, the tolerance for lactose was somewhat higher. Variations in the tolerance for lactose as well as for sucrose seemed to be related to the consumption of hay and water and to the amount of protozoa. Neutralizing the rumen by sodium bicarbonate usually aggravated the condition.