The influence of varying maize supplements on the digestibility of the cellulose in a poor veld hay in relation to the bacterial population of the rumen of sheep with a note on the nitrogen metabolism

Abstract

From the results of a series of metabolism studies on sheep with open rumen fistulae in which a basal ration of winter grazing was supplemented with meatmeal and increasing amounts of crushed maize it was found that: (1) Small amounts of meatmeal and supplements of maize ranging from 50 grams to approximately 150 grams per day favoured the growth of the rumen organisms. Heavier supplements of maize, on the other hand, tended to reduce the number of organisms in the rumen. (2) The increase in the bacterial count did not improve the digestibility of the cellulose in the winter grazing. A progressive depression in its digestibility with increasing supplements of maize was, however, observed. (3) The rectification of the existing protein deficiency in winter grazing with a minimum quantity of protein is futile unless its energy deficiency is simultaneously satisfied.