Composição regional e tecidual da carcaça de genótipos caprinos submetidos a dietas com diferentes relações volumoso/concentrado.

Abstract

Goat farming is a well-developed activity in the Brazilian Northeast region. Goats are animals adaptable to the climate and native vegetation of the caatinga, for this reason the Northeast holds about 92.7% of the country's goat herd. The crossbreeding between SRD goat genotypes with specialized genotypes in higher production such as Boer and Savannah is very common, because the SRD goats have hardiness, but low productivity, which occurs exactly the opposite with specialized breeds, so when this type of crossbreeding is done it seeks to obtain more resistant animals and increases the productivity of herds. In addition, crossbreeding between breeds can increase the weight of the animals, reaching the slaughter phase in less time and greater weight, increasing carcass yield, increased muscularity, better weights of meat cuts, consequently higher income for the producer and product quality for the consumer. Therefore, the objective of the research was to evaluate the regional and tissue composition of the carcass of goat genotypes submitted to diets with different volume/concentrate ratios. The experiment was carried out at the Pendência Experimental Station of the Empresa Estadual de Pesquisa Agropecuária da Paraíba (EMEPA). Thirty goats of different genetic groups (10 SRD, 10 ½ Boer x SRD and 10 ½ Savanna x SRD), with an average age of 120 days and an average initial live weight of 18 kg were used, the goats were confined in cages and subjected to two diets with concentrate:volume ratio (50:50 and 30:70). The goats were distributed in an entirely randomized design in a 3x2 factorial scheme (three genotypes and two diets). When the animals completed 90 days of the experiment, they were slaughtered and the carcass was sectioned, making use of the left ½ carcass to obtain the commercial cuts: neck, shoulder, rib, loin and leg, which were submitted to physical dissection of bones, muscles, fat and other tissues. There was an interaction between genotypes and diets for pallet cut weight, neck cut weight and yield, rib eye intermuscular fat yield, loin muscle and muscle:bone ratio and total fat, and leg intermuscular fat. The regional composition of the carcass of non-bred and mixed Boer and Savannah goats were similar, except for the shoulder weight and neck weight. The tissue composition showed a higher percentage of muscle for those animals improved with Boer and Savannah in all cuts, obtaining effect of the crossbreeding, however the diet with a higher proportion of concentrate did not have a positive effect on the various variables analyzed, indicating that the proportion of lower concentrate already meets the needs of goats.