Effect of copaiba oil on intake, apparent nutrient digestibility, ruminal fermentation, nitrogen balance, and growth performance of lambs in confined conditions

ABSTRACT Two experiments were carried out aiming to evaluate the effect of copaiba oil on growth performance, apparent digestibility of nutrients, and rumen fermentation in lambs on feedlot. The treatments were: no additive inclusion (negative control); 8 mg/kg of sodium monensin (MS; positive control); and 250, 500, and 750 mg of copaiba oil/kg dry matter added to a diet with 70% concentrate and 30% forage. In experiment I, five lambs (Dorper × Santa Inês) cannulated in the rumen, 8 ± 1.0 months old and 51.4 ± 0.7 kg of initial body weight (BW) (mean ± SD), were assigned in a 5 × 5 Latin square design to assess ruminal parameters, apparent digestibility of nutrients, and nitrogen balance. In experiment II, 40 lambs (Dorper × Santa Inês), 8 ± 1.0 months old and 37.7 ± 1.6 kg of initial BW, were registered. The experimental design was in completely randomized blocks (five treatments and eight blocks). The treatments were: no additive inclusion (negative control); 8 mg/kg of sodium monensin (MS; positive control); and 250, 500, and 750 mg of copaiba oil/kg dry matter added to a diet with 70% concentrate and 30% forage. The experimental trial lasted 84 days, divided into three sub-periods of 28 days. Additives did not affect growth performance. Total dry matter intake, individual nutrient intakes, and apparent digestibility were not influenced by feed additives. The additives also did not affect the short-chain fatty acids molar concentration, ruminal pH, and ruminal ammonia nitrogen. Feed additives, in the dosages of 250, 500, and 750 mg of copaiba oil/kg of DM used in this experiment, are not effective to modify growth performance, apparent digestibility, and ruminal fermentation in lambs.