Slaughter performance and meat quality of intact and castrated Washera sheep kept under feedlot condition

Abstract

A study was conducted to evaluate the feedlot performance in carcass traits and meat quality of intact and castrated Washera sheep under low (300 g/day) and high (450 g/day) dry matter (DM) levels of concentrate mix supplementation. The concentrate mix contained 68% wheat bran and 32% noug seed cake. 24 sheep (12 intact and 12 castrated) with age range of 9 to 10 months and initial weight of 24.1±1.8 kg (mean ± SD) were used. A randomized complete block design in a 2x2 factorial treatment arrangement (2 sex category and 2 concentrate levels) was employed. Basal hay was fed ad libitum at a rate of 20% refusal. After 90 days of fattening, all sheep were slaughtered and meat sample from longissimus dorsi muscle of each animal was taken for color and pH measures, and chemical composition analysis. High level supplementation promoted significantly (p<0.001) higher carcass weights, dressing percentage in slaughter body weight (SBW) basis, rib eye-muscle (REM) area, fat thickness (FT), carcass compositions and higher (p<0.05) total edible offal component than low supplementation level. Intact sheep attained higher (p<0.05) SBW (29.4 vs 28.2 kg); empty body weight (23.7 vs 22.9 kg), and produced relatively more carcass yield with higher (p<0.001) muscle, but lower fat composition than castrates. Castrated sheep produced significantly (p<0.01) higher total non carcass fat (0.65 vs 0.46 kg) than intact sheep. Meat from intact sheep comprised of higher (p<0.01) moisture (73.63 vs 72.43%) with lower fat composition (2.06 vs 3.16%) and was less (p<0.05) luminous (L*) in color (34.56 vs 36.63) than castrated sheep. It is concluded that fattening of intact Washera sheep with high level of concentrate supplementation is a better option for production of more carcasses yield with higher proportion of muscle and less fat.   Key words: Carcass composition, dressing percentage, meat color, proximate compositions.