Amonização de feno de Coast-cross

Abstract

This experiment was accomplished in the Animal Nutrition and Pastures Department in the Institute of Animal Science of the Rural Federal University of Rio de Janeiro. The effects of increasing levels of urea addition were evaluated on the chemical-bromatologic and microbiologic composition of Coast-cross hay. The hay was treated with 5 levels of urea (0, 0,5, 1,0, 1,5 e 2,0% of dry matter), during 28 and 35 days. The experimental design used was the completely randomized with five treatments in a split-plot design, two ammonization periods (28 and 35 days) and three replications. Urea (45% N) was used and diluted in the proportion 1 to 4 parts of water. The treated hay was stored in sealed plastic bags (3kg/bag) and, when opened, samples were collected for chemical and microbiological analysis. It was verified that the crude protein levels increased linearly in function of higher doses of urea and period, which suggested an elevation of the nitrogen level available in the material. The addition of urea promoted a significant reduction (P<0,05) on the levels of neutral detergent insoluble protein (NDIP) and acid detergent insoluble protein (ADIP). There was no influence of the ammonization on the levels of neutral detergent fiber (NDF) and hemicelluloses (HEM). The increasing levels of urea were efficient on the reduction of colonies generator unities, keeping them under tolerable levels aiming the preconized limits to vegetable health. The present experiment showed that the process of ammonization is efficient on the improvement of the chemical composition of coast-cross hay.