Effect of slow release urea in sheep feed on intake, nutrient digestibility, and ruminal parameters

This study aimed to evaluate the inclusion of 0.0%, 0.4%, 0.8%, and 1.2% slow release urea (SRU) in sheep feed on the intake and total digestibility coefficient (DC) of nutrients and ruminal parameters of sheep living in tropical regions. Four sheep with a body weight (BW) average of 30.8 ± 1.7 kg were assigned to a Latin square design. The animals were placed in metabolic cages and received two meals a day. Intake data and DC of nutrients of the sheep were subjected to analysis of variance and differences were tested using a regression equation to 5% probability. The inclusion of 0.0%, 0.4%, 0.8%, and 1.2% SRU in sheep feed did not change (p > 0.05) the intake of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral or acid detergent fiber (NDF, ADF), total carbohydrates (TC), and non-fibrous carbohydrate (NFC) expressed in g animal-1 day-1, g (kg0.75)-1, and % BW. The mean values of 3.04%, 2.82%, 0.41%, 0.07%, 1.36%, 0.87%, 2.31%, and 1.00% of BW were obtained for the intake of DM, OM, CP, EE, ANF, ADF, TC, and NFC, respectively. The inclusion of 0.0%, 0.4%, 0.8%, and 1.2% of SRU in sheep rations had a quadratic manner (p 0.05) for different levels of inclusion of SRU in the feed. However, the pH of the rumen fluid did differ (p 0.05) the concentration of ammonia nitrogen (NH3-N) of the rumen fluid, but there was a quadratic effect (p < 0.05) with relation to T for all experimental diets. Thus, we conclude that the inclusion of 0.66% SRU provides the best digestibility value of CP and is the appropriate value for the digestion of DM. The inclusion of up to 1.2% of SRU in sheep rations did not change the intake of nutrients and ruminal parameters.