Evaluation of a residue from monosodium glutamate production (Amniferm) as a non protein nitrogen source for bovines grazing Brachiaria brizantha
Seven crossbred steers, 5 yr of age and 540 kg live weight, were maintained in continuous grazing. In each of three experimental periods, three animals received urea via rumen cannula in daily doses of 50, 100, and 150 g; three others received Amiferm in doses of 240, 480, and 720 mL (corresponding to the nitrogen in the respective urea doses) and one animal served as a control. The experimental design was randomized blocks in time, in a 2 x 3 factorial arrangement (2 nitrogen sources by 3 dose levels) with subplots. Ruminal pH and ammonia concentration were determined hourly over a 12 h period; rumen degradation of B. brizantha dry matter was determined at 0, 3, 6, 12, 24, 48, 72, 96, and 120 h after introduction of samples in nylon bags. With increasing doses of urea and Amniferm, the ruminal concentration of ammonia increased. At 1 h post-dosification the animals that received urea showed a lower rumen ammonia level (P<.05) than those that received Amniferm (378 vs. 1018 mg/L, respectively). At the hours of peak ammonia levels, rumen pH was more acid (P<.05) in animals receiving Amiferm and more alkaline in those receiving urea. Dry matter degradation was not affected by the nitrogen sources, maximum degradation potential being reached at 48 h (71.8%). These results indicate that Amiferm can substitute for urea in the feeding of ruminants.