| This study aimed to evaluate the effects of adding slow release urea to replace conventional urea in diets for feedlot sheep on nitrogen metabolism and microbial protein synthesis. The substitution levels used as treatments were 0, 20, 40, 60 and 80%. We used 25 Santa Ines x SRD sheep distributed in the treatments in a completely randomized design. The animals were given 50% Tifton-85 hay and 50% concentrate, comprising diets with approximately 12% crude protein. The ingestion, digestion and excretion of nitrogen were not affected by the addition of slow release urea to the diet, in which the digested nitrogen accounted for 72.98% of the ingested. The concentration of plasma urea-N showed a quadratic variation, with the maximum at the level of 72.18%... |
