Efeito da inclusão do grão de girassol nas características da carcaça e carne de bovinos confinados

Abstract

The use of vegetable fat sources, such as sunflower grain, has aroused interest in the nutrition of ruminants, as it has a high level of ether extract and a high concentration of unsaturated fatty acids in its composition, which can characterize changes in the characteristics of carcass and meat. The objective of this work was to evaluate levels of inclusion of sunflower grain in the diet, on carcass characteristics and meat quality of non-castrated male cattle, finished in feedlot. 36 steers with an initial mean age of 20 months and an initial mean live weight of 292.14 ± 9.20 kg were used, originating from the crossing between the Charolais and Nellore breeds. The experimental design was completely randomized. The steers were randomly distributed in the following treatments: control (without inclusion of sunflower grain), 50, 100 and 150 grams of sunflower grain per kilogram of dry matter in the diet. The experimental diets contained a 48:52 roughage: concentrate ratio and were adjusted to be isoprotein. The inclusion of sunflower grain in the diet does not change the slaughter weight, hot and cold carcass weight, rib eye area and subcutaneous fat thickness of the carcass. Steers that received up to 150 g/kg DM in the diet show higher values for thickness of the cushion. The total fat content in the carcass has the opposite behavior as the level of inclusion of this oilseed increases. The carcass conformation showed a quadratic effect with a minimum point for inclusion of 64.84 g/kg DM of sunflower grain. The inclusion of different levels of sunflower grain changes some characteristics of the meat. In view of this, there was a quadratic effect for the variables marbling and succulence with maximum point for marbling in the inclusion of 50 g/kg DM and minimum point for succulence in the inclusion of 88.8 g/ kg DM of sunflower grain in the diet. The increase in the sunflower content in the finishing diets linearly reduces the losses of liquids to thawing and cooking, however, it produces meat of a darker color.