2. CARCASS QUALITY

Increased meat production in Tunisia and Libya is a priority item in their agricultural policy to satisfy the animal protein needs of their people. To reach this objective, the number of newborn lambs has to be increased together with an improved growth rate and dressing percentage, so that a heavier carcass is obtained. Actually, lambs are slaughtered at a mean liveweight of 25 g when they are 4 to 6 months old.. If this liveweight were increased to about 35 g it would certainly be one of the best ways to increase national meat production. However, carcass quality could be lowered by increasing the liveweight of Barbary lambs due both to the fat-tail and its subcutaneously deposited fats.

The relationship of carcass quality with liveweight was studied in Barbary ram lambs by Atti and Khaldi (1987). In this study, 10 ram lambs were slaughtered at a liveweight of 25 g and 10 others were slaughtered at a liveweight of 35 g. The dressing percentage was 43 percent in light lambs and 48 percent in heavy lambs. The weight of the fat-tail represented 6.3 and 7.2 percent of the carcass weight when lambs were slaughtered at 25 and 35 g liveweight respectively. Similarly, the animals slaughtered at 35 g exhibited significantly larger amounts of internal and external fat than light lambs. In effect, the thickness of the dorsal fat was 1.65 mm in lambs slaughtered at 25 g and 4.67 mm when the liveweight increased to 35 g. On the other hand, the pelvic and renal fat weight increased from 90 to 140 g when liveweight at slaughter increased from 25 to 35 g. The carcass composition was as follows: