| Autor: |
Dos Santos NJA; Department of Animal Science, Federal University of Bahia, Salvador 40170110, BA, Brazil., Bezerra LR; Department of Animal Science, Federal University of Campina Grande, Patos 58708110, PB, Brazil., Castro DPV; Department of Animal Science, Federal University of Bahia, Salvador 40170110, BA, Brazil., Marcelino PDR; Department of Animal Science, Federal University of Bahia, Salvador 40170110, BA, Brazil., de Andrade EA; Department of Animal Science, Federal University of Bahia, Salvador 40170110, BA, Brazil., Virgínio Júnior GF; Department of Animal Science, Federal University of Bahia, Salvador 40170110, BA, Brazil., da Silva Júnior JM; Department of Animal Science, Federal University of Bahia, Salvador 40170110, BA, Brazil., Pereira ES; Department of Animal Science, Federal University of Ceará, Fortaleza 60021970, CE, Brazil., Barbosa AM; Department of Animal Science, Federal University of Bahia, Salvador 40170110, BA, Brazil., Oliveira RL; Department of Animal Science, Federal University of Bahia, Salvador 40170110, BA, Brazil. |
| Abstrakt: |
Vegetable oils can be used to increase energy density in diets; manipulate rumen fermentation; and alter the capacity for degradation, digestion and absorption of nutrients. Two experiments were conducted to evaluate palm kernel oil (PKO) in the diet of confined bulls with the inclusion of 0.0, 11.5, 23.0 and 34.6 g PKO/kg dry matter (DM). The first experiment evaluated nutrient intake, performance, ingestive behavior and carcass characteristics. In the second experiment, steers crossbred with a ruminal cannula were used to evaluate digestibility, nitrogen balance, microbial protein synthesis, short-chain fatty acid levels and protozoal counts. The results showed that the inclusion of PKO linearly reduced intake in kg/day (DM, crude protein-CP, neutral detergent fiber-NDF ap , nonfibrous carbohydrates-NFC and total digestible nutrient-TDN) and digestibility (DM, NDF ap and TDN). Ether extract intake increased quadratically with the predicted maximum intake of 15.4 g/kg DM. Regarding ingestive behavior, there was a quadratic increase in rumination time and a quadratic reduction in idle time. Nitrogen balance, nitrogen intake, nitrogen retention, microbial protein production, acetate, butyrate, acetate/propionate ratio and protozoa count showed linear decreases due to dietary PKO inclusion. Regarding the carcass characteristics, linear decreases were observed for the final weight, average daily gain, hot carcass weight, cold carcass weight, hot carcass yield, cold carcass yield, loin eye area and subcutaneous fat thickness. The inclusion of PKO at up to 34.6 g/kg DM in diets for confined bulls reduces intake, negatively affecting digestibility, performance and carcass characteristics. |
