ABSTRACT:The objective of this study was to evaluate the biometry and carcass characteristics of finished Santa Inês crossbred sheep grazed on tropical grass pastures during the dry season. The study was carried out at the Grupo de Estudos em Forragicultura (GEFOR/UFRN), in Macaíba -RN, Brazil. Four forage treatments were evaluated: Brachiaria brizantha cvs. Marandu e Piatã, Panicum maximum cvs. Aruana e Massai. The 2.88 ha-area used was divided in two blocks of 1.44 ha; each one was composed of four plots corresponding to each cultivar, and each plot was subdivided into six paddocks with an area of 0.06 ha. The pastures were managed under intermittent stocking with seven days of occupation and 35 days of rest, with variable stocking rate. No significant difference was observed in the biometric measurements evaluated in the animals, except for chest width in which animals kept in Marandu pastures obtained higher values than those in the Aruana cultivar. The lowest values of average daily gain, final weight and weight at slaughter values were observed in the animals kept in Aruana cultivars. Cut weights of the shoulder, the loins, short legs/shanks and ribs were higher in the animals kept in Marandu grass and lower in those kept in the Aruana grass; however, no differences were observed for the yield of the cuts and for the biometric measurements of the carcass. The evaluated pasture cultivars did not modify the finished sheep carcasses, however, the lower forage mass from Aruana grass pastures in the dry season affected animal performance and the sheep carcass composition.

Thirty-two Santa Inês male lambs, not castrated, were distributed in a randomized block design to evaluate the effects of different tropical forage cultivars (two Panicum maximum (Syn. Megathyrsus maximus): Aruana and Massai, and two Brachiaria brizantha (Syn. Urochloa brizantha) Marandu and Piatã) on carcass characteristics, quality, physical composition, and meat chemistry. The data were subjected to an analysis of variance, and the means compared using the Tukey test at 5% significance. There was no effect of cultivars on body weight, slaughter weight, and biometric measurements of the carcass. The Aruana and Piatã cultivars provided higher weights of hot and cold carcasses when compared to the Massai and the Marandu had no significant differences compared to the others. The animals kept in the pasture of the Aruana cultivar showed higher shank yields. However, forage cultivars did not affect the ribeye area or subcutaneous fat thickness. There was also no effect of cultivar on pH, temperature, cooking losses, cooling losses, and meat shear strength. The cultivars did not change the quality and composition of the meat. However, the Aruana, Piatã, and Marandu cultivars were the ones that provided higher carcass weights and ham yields.

The objective of this study were to examine the effects of diets containing spineless cactus associated with hays of different legume species [gliricidia (Gliricidia sepium), “catingueira” (Caesalpinia bracteosa), “sabiá” (Mimosa caesalpiniifolia Benth) and “catanduva” (Piptadenia moniliformis Benth)] on the intake, digestibility, performance and carcass traits of lambs. Twenty-four ½ Santa Inês × ½ Soinga lambs with an average body weight of 21.4 ± 2.53 kg were distributed into four treatments in a completely randomized design. Treatments consisted of diets formulated with the association of spineless cactus (Opuntia ficus-indica Mill) and hay of four legume species, namely, “catanduva”, “sabiá” “catingueira” and gliricidia. The lowest intakes (P<0.05) of dry matter (DM), organic matter (OM), neutral detergent fiber (NDF) and total carbohydrates occurred in the animals that received the diet containing catingueira hay. However, there were no diet effects (P>0.05) on the intakes of crude protein (CP), ether extract and non-fibrous carbohydrates. The diets also did not change (P>0.05) the weight gain (0.197 kg/day) or final weight (33.18 kg) of the lambs or the apparent digestibility coefficients of DM, OM, CP and NDF. Consequently, the parameters of live weight at slaughter (34.10 kg), hot carcass weight (14.81 kg), cold carcass weight (14.66 kg), hot carcass yield (45.60%) and cold carcass yield (45.07%) exhibited the no response to treatment. In addition to these variables, the diets also did not influence subcutaneous fat thickness (2.54 mm), longissimus muscle area (13.34 cm2), morphometric measurements of the carcass, or the proportions of muscle and fat. Therefore, legume hays associated with spineless cactus can be used to feed ½ Santa Inês × ½ Soinga lambs in the feedlot, as this strategy provides heavy animals at the time of slaughter and carcasses with desirable degrees of muscularity and adiposity.