Effect of type of suckling and polyunsatured fatty acid use on lamb production. 1. Productive performances and quanti-qualitative characteristics of the carcass

The aim of the study was to estimate the influence of artificial rearing and of the addition of polyunsaturated fatty acids (PUFA) to an acidified milk replacer on the productive performances and on the quanti-qualitative characteristics of the carcass. Fifty one twin-born Gentile di Puglia lambs were subdivided into three homogenous groups (9 females and 8 males) assigned the following feeding treatments: maternal milk (MM); acidified milk replacer (MR); acidified milk replacer + 10 ml/l of a mixture of linseed and fish oil rich in PUFA (MR+PUFA). Milk consumptions and live weights were recorded weekly. Seven males from each group were slaughtered at 45 days of age and the net warm dressing percentage, the composition of the carcass and the colorimetric characteristics of the Longissimus lumborum muscle were estimated. Artificial rearing improved the daily weight gain (0.182-0.172 vs 0.128 Kg; P<0.01) of lambs, provided fatter carcasses and meat with a better red index (6.16-6.43 vs 8.03; P<0.01). The addition of omega-3 fatty acids to the diet did not influence the weight gain, the feed conversion index, the net warm dressing percentage and the incidence of the different meat cuts of the half carcass. However, it significantly increased the half carcass length (37.86 vs 35.0 cm; P<0.05), the thoracic depth (19.71 vs 16.50 cm; P<0.01) while, it compared to the MR group reduced the proportion of lean (63.21 vs 53.98 %; P<0.01) in favour of bone (20.94 vs 29.40 %; P<0.01) in the lumbar region.