Características de carcaça e qualidade da carne de tourinhos nelore submetidos a dietas com níveis de torta de dendê, oriunda da produção do biodiesel

Abstract

This experiment was conducted to determine the best inclusion level of palm kernel cake by analysis of carcass qualitative characteristics and meat quality. 32 young bulls Nellore were used, with 420± 25 kg/LW. The animals were fed with Tifton-85 hay and concentrated mix with corn meal, soybean meal, mineral premix and palm kernel cake in 0.0; 7.0; 14.0 and 21.00% inclusion in total DM, those levels constituting the treatments. Feedlot lasted 84 days. At the end of the experimental period, the animals were subjected to 16h fasting, weighted and slaughtered for determination of carcass quantitative characteristics, hot carcass weight (HCW) and calculation of hot carcass yields, measured by the ratio between total carcass weight and weight at slaughter. Next, the half carcasses were transferred to the refrigeration room at 4oC , where they remained for 24h. After that, carcass conformation, carcass length and cushion thickness were evaluated. At the level of the 12th rib, half carcasses were sectioned for measurement of backfat thickness, Longissimus dorsi muscle area and subjective evaluations of meat color, texture and marbling. From the left half carcass, between the 9th and 12th ribs, samples were taken for posterior analysis of nutritional characteristics (centesimal characteristics and fatty acids profile), physicochemical (pH, color, water holding capacity, cooking loss and shear force) and sensorial meat evaluation (flavor, texture, global acceptance and preferences). Data were submitted to variance and regression analysis. There were no effect of the palm kernel cake inclusion levels over the carcass quantitative characteristics, with the exception of HCW, which linearly reduced. Also, there were no effect over the subjective qualitative characteristics of the carcass (meat color, texture and marbling), centesimal composition, physicochemical and sensorial evaluation of the meat. However, the fatty acids profile did alter with the inclusion levels of palm kernel cake, with increasing of the miristic acid and decreasing of the linoleic and arachidonic acids. Palm kernel cake, originated from the biodiesel production, may be included in young bulls diets up to 21%. However, the linear reduction in hot carcass weight and the content of polyunsaturated fatty acids should be considered in the overall evaluation of the use of this coproduct for feedlot.