Commercial crossbreeding between Ile-de-France, Rambouillet, Chios and local fat-tail Awassi for market lamb production

Abstract

A commercial crossbreeding experiment at the Research Farm of Çukurova University in Adana with Ile-de-France, Rambouillet, Chios and Awassi sheep is reported. The Chios breed was chosen for prolificacy and high milk production potential, the Ile-de-France for early growth and carcass quality, and the Rambouillet for early growth; the Awassi is the local sheep which is to be improved. The objective was to increase meat production by exploiting the reproductive efficiency of crossbred sheep. Firstly, Awassi ewes were mated with Chios rams, producing the F 1 generation. Secondly, the F 1 ewes were mated with Ile-de-France sires to obtain F 1 ram lambs (designated IlF 1), and F 1 ewes were also mated with Rambouillet sires to obtain F 1 ram lambs (designated RF 1). Rambouillet (Rmb) and Awassi (Aw) sheep served as the control lines. Lambing rate (lambs born per mated ewe) was 1.65, 1.16, 1.05 and 1.03 for Il × F 1, R × F 1, Aw × Aw and Rmb × Rmb matings respectively. Twelve ram lambs in the IlF 1, RF 1 and Aw groups, and eight Rmb ram lambs were used in a fattening trial. Ram lambs weighing 38–40 kg were slaughtered and the chilled carcass was divided into eight primal cuts. Average daily gains were 311.6, 253.2, 281.2 and 226.0 g for IlF 1, Aw and Rmb lambs, respectively, and feed efficiency was 3.8, 4.2, 3.7 and 5.4. Dressing percentage was higher for IlF 1 lambs than for other groups. For cold carcasses of IlF 1, RF 1 Rmb and Aw lambs, the total bone percentage was 18.8, 19.5, 19.5 and 19.7 respectively, total muscle percentage 54.9, 53.5, 54.3 and 54.1, total subcutaneous fat percentage 12.3, 14.1, 11.6 and 16.6, and total intermuscular fat percentage 10.5, 9.5, 10.1 and 6.6. Fat thickness and rib-eye areas at the 12th rib were generally largest for IlF 1 ram lambs.