Animal performance and meat quality in feedlot cattle feeding with different levels of agricultural by-products

Objective. Evaluate the effects of different levels of agricultural by-products concentrate on animal performance and meat quality in feedlot cattle. Material and methods. Thirty-Six F1 Bos taurus x Bos indicus bulls were used with 347±20 kg of body weight and 18 months average of age on feedlot under tropical dry forest conditions. Experimental treatments were levels of agricultural by-products replacing Pennisetum sp grass to 85% forage:15% concentrate (T1); 75% forage:25% concentrate (T2); 65% forage:35% concentrated (T3) and 55% forage:45% concentrate (T4). A completely randomized experimental design was used for evaluation variables as live weight gain (LWG), dry matter intake (DMI), feed efficiency (FE), hot carcass weight (HCW), carcass yield (CY), blood metabolites and fatty acid profile in meat. Results. LWG and final weight increased with a higher level of concentrate in the diet (p<0.043). There were not differences in blood metabolites. Differences in caproic, caprylic and tridecanoic saturated fatty acids were observed when level of concentrate in diet increased (p<0.05) while, in unsaturated and polyunsaturated fatty acids has been not differences between treatments. Conclusions. Inclusion of agricultural by-products improved animal performance and three saturated fatty acid decreased in F1 Bos taurus X Bos indicus bulls under feedlot in tropical dry forest conditions.