The inclusion of rapeseed meal in young Barbarine lambs' diets as a partial replacer of soybean meal: Effects on growth, carcass performances, non-carcass traits and meat quality

The main objective of this study was to determine the effects of rapeseed meal (RSM) substitution to soybean meal (SBM) in concentrate at different rates on growth performance, carcass traits and meat quality of fat-tailed Barbarine lambs. This experiment focused on 21 male lambs (10 months old) averaging a body weight (BW) of 24.8 + 2.4 kg, assigned to 3 homogeneous groups of 7 lambs each. All lambs received 600 g of oat hay as roughage and 3 types of concentrate: a control concentrate (C) and two experimental concentrates containing RSM that substituted SBM at rates of 50 (RS50) and 75% (RS75). The trial lasted 77 days after which all the lambs were slaughtered at an average body weight of 31.5 kg. Then, samples of Longissimus thoracis et lumborum (LTL) were collected and conserved for further meat analyses. Results showed that total dry matter and crude protein intakes were similar for all lambs. Lambs reached similar final BW; however, average daily gains (ADG) were affected by the diet being higher for C and RS50 groups than RS75 (P < 0.05). The hot and cold carcass weights and the dressing percentages (real and commercial) were similar for all groups (P > 0.05). The non-carcass components were similar for all groups (P > 0.05). In terms of proportions in the carcass, no difference was recorded for all joints weights except for the tail which was heavier in C and RS50 groups. Diets had no effect on tissue composition, subcutaneous and intermuscular fat. The RS75 lambs had higher pelvic fat compared to other lambs. The incorporation of RSM did not alter meat physico-chemical attributes, color and lipid oxidation. In conclusion, the substitution of SBM by RSM in the concentrate especially at a rate of 50% did not alter growth performance and meat quality in Barbarine lambs.