EFFECTS OF FEEDING SYSTEM AND BREED ON LAMB PRODUCTIVE AND CARCASS CHARACTERISTICS IN THE SOUTH MEDITERRANEAN REGION

The objective of this study was to evaluate the effect of feeding regimes and breed type on growth, non-carcass components and carcass characteristics of light lambs. Twenty four light lambs from the rustic fat-tailed Barbarine (BB) breed and 21 from the thin-tailed Sicilo-Sarde (SS) breed were used. For each breed, animals were divided into 3 groups (8 BB and 7 SS breed, each) by live weight (LW). Two groups were conducted on rotational grazing of barley grass (GB) or perennial ryegrass (GR) and received daily 350 g of concentrate per lamb. The last group was conducted on feedlot system (FL) with 450 g of ryegrass hay and 650 g of the same concentrate per lamb per day. The whole grass yield was 5 t DM/ha for ryegrass prairie and 4.2 for barley one. The final LW was higher for GB and GR lambs (28.3 kg) than for FL ones (26.9 kg). Irrespective to breed, the average daily gain was higher for both grazing groups than FL system, 144, 137 and 121 g for GR, GB and FL regimes, respectively. Slaughter LW was higher for BB (29.0 kg) than SS breed (26.5 kg). Barbarine lambs had more fat (23 vs. 17%) and less muscle (53 vs. 57%) than SS ones. FL lambs carcasses were more adipose (26%) than those of both grass groups (18%), while grass lambs had more muscle (57 vs. 51%). Grazing grass based diets increased carcass muscle and decreased fat proportions, which could be a useful feeding strategy to naturally manipulate lamb meat nutritional characteristics.