Desempenho e características de carcaça de genótipos caprinos submetidos a dietas com diferentes relações volumoso/concentrado.

Abstract

Goat farming has significantly increased its participation in the Brazilian agricultural scenario, mainly because it is an important alternative for livestock development in the semiarid region of the Northeast. However, there is not always vegetation present and nutritional characteristics that meet the requirements of animals, especially when specialized breeds are used, as these nutritional requirements increase to achieve good productive performance. Therefore, it needs a multiple complex between adapted genotypes and good production allied with food management and breeding techniques in order to obtain good yields and profits in goat production. The use of crosses between SRD animals and specialized breeds for meat production may increase the same, and these genotypes resulting from these crossbreeding involving specialized breeds for cutting have higher nutritional requirements. Some exotic breeds and / or racial types such as Boer and Savana have been introduced in Brazil with the intention of genetically improving the yield and carcass quality of the herd. The objective of this study was to evaluate the carcass characteristics of different goat genotypes submitted to diets with different ratios of concentrate / concentrate in confinement. The experiment was conducted at the Experiment Station of Pendência, EMEPA-PB, Soledade. We used 30 goats of the genetic groups: SRD, ½ Boer x SRD and ½ Savana x SRD, with an average of 120 days of age and 18 kg of live weight. The goats received two different diets: 50 voluminous/50 concentrate and the other with 30 voluminous/70 concentrate. The experimental design was completely randomized with treatments in a 3x2 factorial scheme (genetic groups x two large: concentrate ratio) and five replications. For the total weight gain (GPT) and the average daily weight gain (GPMD), interaction between the factors (genotypes vs. voluminous ratio: concentrate) (P <0.05) occurred as well as interaction (P <0.05) for slaughter weight (AP) among animals receiving the 30 V: 70C diet. There were significant differences (P <0.05) in the carcass constituents, for the skin, reproductive system, heart and legs. For the diet, there was a difference in hot, cold, weight loss and cooling performance, and the diet with a 30:70 V: C ratio gaining advantage over 50:50 V: C, with the exception of loss by cooling. In relation to carcass morphometry, the genotypes showed statistical differences (P <0.05), for chest depth andcarcass length, and in diets there were differences for croup width and leg perimeter (P <0.05). In the evaluation of the qualitative characteristics of carcasses of the different goat genotypes, a significant difference (P <0.05) was observed only for conformation and finishing, where the Savana and Boer mestizos were similar to each other, but both were superior to SRD. The performance of crossbred goats Boer and Savana are superior to animals without racial pattern, when fed with diet with 50:50 ratio and 30:70 bulky concentrate. The crossbred animals improved the quantitative classification (conformation and finishing), that is, they increased the edible portion of the carcasses.