The Microbial Flora of the Rumen of Cows Fed Hay and High Cereal Rations and its Relationship to the Rumen Fermentation

Abstract
Summary.: The rumen microbial population associated with feeding cows 3 rations, hay alone, 20% hay/80% flaked maize and 20% hay/80% rolled barley has been examined. The differences between the hay and the cereal rations were considerable but between the cereal rations only slight. Both cereal rations provoked & large drop in the proportion of butyrivibrios, and a rise in the proportion of selenomonads, peptostreptococci, lactobacilli and bifidobacteria. The importance of these and other changes occurring in the microbial flora are discussed in relation to their possible effect on the products of the rumen fermentation.