Carcass composition of Naeemi, Texel, Chios, Naeemi x Texel and Naeemi x Border Leicester - Merino lambs

SUMMARY Thirty nine lambs of 5 genetic groups including fat-tailed Naeemi (N), thin-tailed Texel (T), and semi-fat tailed Chios (C), NxT and N x Border Leicester-Merino (NxBLM) were fed a 17% crude protein diet with a 4: 1 ratio of concentrate to alfalfa hay and were slaughtered at a mean weight of 45 kg. A side of each carcass was dissected into subcutaneous fat, muscle and bone, and dissected components were weighed separately to determine composition of individual carcasses. Dressing percentage was calculated as 100 x dressed hot carcass weight/fasted liveweight. The aim of the trial was to compare dressing percentage and carcass composition of lambs of the 5 genetic groups adjusted to the same slaughter weight. Overall least squares means for dressing percentage, tail weight, half-carcass weight and weights for subcutaneous fat, muscle and bone were 44.9% and, 1.12, 10.1, 0.79, 7.4 and 1.69 kg, respectively. Dressing percentage was the lowest for N (39.4 %) and the highest for NxT (47.5%); subcutaneous fat was the lowest for T (0.32 kg) and the highest for NxT (1.39 kg) and muscle was the lowest for N (6.6 kg) and the highest for NxT (8.1 kg). Tails of the N lambs were 5.4, 3.1, 3.9 and 3.3 times heavier than the T, C, NxT and NxBLM lambs. Genetic group differences were significant for dressing percentage, half-carcass weight, tail weight and subcutaneous fat (PcO.Ol), but were not significant for muscle and bone. The effect of sex, and genetic group x sex interaction was not significant for any of the traits studied. In this study, Texel carcasses were superior in composition to those of C, N and N cross lambs.