Efeito de diferentes ureias comerciais para a nutrição de ruminantes pelo método de produção de gás in vitro

Abstract

This study aimed to evaluate the in vitro gas production of different commercial urea sources, comparing conventional urea with four types of slow-release urea, mixed with ground corn. The experiment was conducted at the Animal Bromatology Laboratory of the Federal University of Technology – Paraná, using the in vitro gas production technique to estimate ruminal fermentability. The samples consisted of 0.5 g of ground corn with the addition of 25, 50, 75, and 100 mg of urea. Ground corn was used as the control substrate due to its high digestibility. All mixtures were incubated simultaneously, and gas volume readings were taken at 1, 2, 4, 6, 8, 10, and 24 hours after the start of incubation. The results indicated that feed-grade urea showed lower gas production during the intermediate hours (6 to 10 h), suggesting rapid ammonia release, which may inhibit fermentation. In contrast, the slow-release ureas showed fermentation patterns closer to that of ground corn, suggesting better synchronization between nitrogen release and the availability of fermentable energy. Although most differences were not statistically significant, the observed trends indicate superior potential of slow-release ureas in ruminant nutrition.