Desempenho, características de carcaça e exigências nutricionais de proteína e energia para ganho de cordeiros Santa Inês e ½ dorper x ½ Santa Inês em pastejo na região semiárida.

Abstract

Being the Caatinga biome, the food supply based on the power of sheep raised extensively in the semi-arid region, it is of relevance important studies that will evaluate the development of the sheep, from birth to slaughter, taking as parameters the performance and nutritional requirements requested by species, aiming good carcass characteristics, taking into account the quantity and quality of available forage at certain times of year. In this sense it is important, animal feeding systems during drought periods avoiding the decrease of the production capacity of the herd. The experiment was conducted at Fazenda NUPEÁRIDO, experimental unit belonging CSTR / UFCG were used 36 lambs, male, not neutered, 18 Santa Ines and 18 F1 (Dorper x Santa Inês), these twelve animals were used as reference, six of each racial group and the remaining 24 were divided into three treatments, with average initial weight of 15 kg. The treatments consisted of three food intake levels set according to the grazing times (nine, six and three hours of grazing) and their level of supplementation. The distribution of animals in treatments occurred with the formation of homogeneous lots of three animals from each treatment being one, as it reached the same weight. When a batch of animals reached 30 kg body weight of the respective batch was slaughtered. The concentrated mixture was offered to the end of the grazing period, being prepared from corn meal, soybean meal, mineral mix and limestone adjusted so that met the recommendations in Metabolizable Protein (MP), Metabolizable Energy (ME) and Calcium and Phosphorus, estimating an average weight gain of 200 g / day. The results were analyzed using Proc GLM of SAS through a completely randomized design in a factorial arrangement 3 x 2 (grazing time x genetic group) and carried an analysis of variance, where the average of the significant variables were submitted to the Turkey 5 test %. The animals were weighed every seven days always 08:00 am, with fasting for 15 hours for evaluation of performance. For the analysis of housing it was carried out the comparative slaughter of animals and when one of the animals reached 30 kg of live weight, the remaining animals in the group were slaughtered, and made measurements of carcass components: PJ, PCQ, PCF, PCV, PES, PCOS, PERT, PGAR, and yields: RB, WHR, RL, RCOS, RPER, PPR and ICC. The body composition of energy and protein was estimated by deriving logarithmic equations (Log y = a + b * log x). The nutritional requirements of protein and energy for weight gain were estimated through derivation of logarithmic equations of body composition. The variation of the initial and final weight was significant (P <0.05) for the racial group Dorper 1/2 1/2 Santa Inês, but the average weight gain was similar (P> 0.05). Assessing the average weight gain among grazing levels, a statistical difference (P <0.05). The body composition of protein per kg / PCV in sheep's racial group 1/2 Dorper was 155.70, surpassing (P <0.05) the 153.80 racial group Santa Ines. The net requirements of energy did not differ between the racial groups studied (P> 0.05). Therefore, grazing in semi-arid conditions, the nutritional requirements of the studied breeds were met, culminating with adequate housing characteristics.