Growth at fattening and carcass characteristics of D'man, Sardi and meat-sire crossbred lambs slaughtered at two stages of maturity.

The objective of this study was to evaluate growth at fattening, carcass characteristics and carcass measurements of 19 Sardi, 19 D'man and 52 meat-sire crossbred lambs of both sexes slaughtered at 50 and 70 % of mature weight. Crossbred lambs were born from Sardi, D'man and F1 Sardi × D'man ewes mated to meat-breed rams (Ile de France and Mérinos Précoce). Lambs of each group (breed type by sex) were chosen at random and slaughtered either at 50 or 70 % of mature weight. Sardi and D'man purebred lambs had significantly lower growth at fattening, pre-slaughter live weight, empty body weight, hot carcass weight, carcass conformation, carcass fatness, red offal, white offal, sub-products and non-carcass fat than meat-sire crossbred lambs. Differences were 42.2 g/day, 5.03 kg, 4.46 kg, 2.57 kg, 0.96, 0.59, 0.18 kg, 0.39 kg, 0.63 kg and 0.12 kg, respectively. B and Wr measurements of meat-sire crossbred lambs were higher than those of Sardi and D'man purebred lambs, whereas the F measurement was in favour of purebreds. Likewise, CC, G/F and Wr/Th indices of meat-sire crossbreds were higher than those of purebreds; however, the opposite was observed for L/G and Th/G indices. Maternal heterosis was positive and not significant for most traits, negative and not significant for few traits (P > 0.05), but negative and significant for the proportion of sub-products (P < 0.05). It was concluded that growth and carcass characteristics of local sheep can be significantly improved by terminal crossbreeding.