Consumo e digestibilidade de nutrientes em bovinos submetidos a diferentes níveis de uréia

Abstract

The dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), crude protein (CP), non fiber carbohydrate (NFC), eter extract (EE) intake and apparent digestibility and total digestible nutrients (TDN) in cattle fed with Brachiaria brizantha La Liberdad, low quality hay, with increasing urea levels, were evaluated. Were used five Nellore steers, male, castrated, canuled, distributed in latin square among the treatments 1: control, only hay and increasing urea levels added directly in the rumen aiming to increase in 2: 2 %, 3: 4 %, 4: 6 % and 5: 8 % the CP in the diet. The DM, OM and NDF intakes linearly increased when raised from 3.4 to 9.9 % CP in the diet and decreased in 11.6 % CP. The NFC and EE intakes didnt differ. The urea inclusion didnt influenced the DM, OM, NDF and NFC digestibilities. The CP digestibility showed quadratic effect. To increase DM intake by cattle fed diets based on exclusive hay of Brachiaria brizantha La Liberdad with low protein content (2.9 % CP) and high content of neutral detergent fiber (NDF 77 %), it is suggested the CP suplementation with urea up to the level of 10 % CP.