Meat centesimal composition and tenderness of bovine growing in pasture during the wet season receiving supplementation and finished on pasture or feedlot

The inclusion of concentrate in the feedlot or pasture cattle diet positively influences the meat tenderness. The aim of this research was to evaluate the effects of growth system in the wet season on the chemical meat composition and tenderness of young bulls Nellore finished in the dry season in pasture or feedlot. The bulls were kept during the growing phase grazing Marandu grass and finished during the dry season on pastures or feedlot system. Six treatments were evaluated: growing phase on pasture of 15 cm of grazing height + supplement (0.6% BW): growing phase on pasture of 25 cm of grazing height + supplement (0.3% BW): growing phase on pastures of 35 cm of grazing height + mineral mixed supplementation. Half of the bulls from each treatments of the growing phase were finished on pastures associated with supplementation and another half, finished on feedlot system, receiving the same supplement. The bulls were slaughtered, with body weight average of 515 kg, samples of the Longissimus muscle, from the left half carcass between the 12th and 13th ribs were removed and analyzed for tenderness and chemical composition. The experimental design was completely randomized, in a factorial arrangement (3 growing systems x 2 finishing systems), with nine replications (bulls) per treatment. Were applied normality tests and analysis of variance (P < 0.05), using the PROC MIXED from SAS(R) software proceeds. The growing systems in the wet season and pasture finishing did not change the tenderness and the centesimal composition (P > 0.05) of the meat samples evaluated. However, the percentage of protein was affected by the finishing system, where animals finished in feedlot showed higher protein levels (P = 0.02). The supplementation on rearing phases with different pasture height and differents levels of supplement on finished do not alter tenderness. The feedlot system alter the meat protein level.