The objective of this paper was evaluate ammonia concentration, pH of ruminal liquid and microbial synthesis efficiency in diets with different energetic sources: corn (CO), corn/cassava hulls (CC), cassava root (CR) and cassava by-product flour (CB). Four Holstein steers (270 kg) were used, in a 4 X 4 Latin Square design. The marker utilized for determination of duodenal and fecal flow was the acid insoluble ash. There was not effect in the ruminal pH of the experimental diets, however smaller ammonia concentration was observed to the diet with CB. The organic matter and nitrogen flow to duodenum and chemical composition of ruminal bacteria were not influenced by experimental diets. The higher apparent microbial efficiency was obtained to CB diet. In the conditions of the present experiment the CB possibly presented better synchronization with the protein source (soybean meal), decreasing the loss of nitrogen under N-NH3 form and increasing the microbial efficiency.
cassava by-product flour; cassava hulls; corn; steers; cassava root
