Effect on production and carcass quality characteristics of wether lambs of crossing Blackheaded Mutton,Ile de France and Texel rams with Polish Merino ewes

During the period 1972–1974 investigations were made on 120 wethers fattened semi-intensively to a weight of 45 kg liveweight. These lambs originated from commercial crosses of the Polish Merino with rams of the breeds Blackheaded Mutton (B), Ile de France (IF) and Texel (T) as well as pure Merino (M) in the control group.The use of rams of these meat-producing breeds as compared with Merino gave a better growth rate: an increase in the group IF × M of 6.2%, B × M of 7.8% and T × M of 8.8% respectively. The feed consumption, expressed in starch equivalents per kg of weight, decreased in group IF × M by 11.6%, B × M by 15.1% and T × M by 15.6%, and total digestible protein decreased in the group IF × M by 12.1%, B × M by 16.6% and T × M by 16.9%.Crosses with Blackheaded Mutton and Ile de France rams did not fundamentally change the tissue composition of the lamb carcasses. However, the use of Texel rams resulted in carcasses with a higher lean content and less fat as compared with pure Merino (difference 5.7%) as well as with other crosses (differences 4.2–4.8%).Rams of the meat breeds tested did not greatly influence dressing percentage and carcass yield in terms of bone content and the proportion of valuable cuts; nor were dimensions affected, except for a decrease in length of 2–3.5% compared with Merino.