Effect of nutritional status of rabbit kits on their productive performance, carcass and meat quality traits

The effect of nutrient supply at foetal, suckling and growing ages on productive, carcass and meat quality traits of rabbits was studied. New-born rabbits were divided into three groups according to their birth weight (low/L/: 35-50 g, medium/M/: 58-62 g and high/H/: 70-88 g). Half of the litters were nursed by one doe (O) and the other half by two does (T). The kits were weaned at 3 weeks. From the age of 4 weeks, half of the rabbits were fed ad libitum (A), or on a restricted regime (R) (85-90% of the ad libitum feed intake level). Rabbits were slaughtered at 11 weeks of age. Difference in average feed intake between groups L and H, groups O and T and between R and A was 11.2%, 7.8% and 11.7%, respectively; in all cases, the latter groups had the highest intakes. Body weight gain between 3 and 11 weeks was significantly affected by birth weight and feeding regime. Body weight at slaughter of L rabbits was 124 g lower than that of M rabbits and 255 g lower than that of H rabbits (P < 0.05). Group L had the highest dressing out percentage (58.0%), whereas M rabbits had the lowest dressing out percentage (57.3%) (P < 0.05). Ratio of hind part of the reference carcass was higher in group H (39.0%) than in group L (38.1%) (P < 0.05). Percentage of perirenal fat was the highest in L rabbits (2.10%) and the lowest in group H (1.64%) (P < 0.05). Slaughter weight of T rabbits was 198 g higher (P < 0.001) than that of group O. Chilled carcass weight and dressing out percentage were 16 g (P = 0.006) and 0.7% (P = 0.002) lower, respectively, in T rabbits. In consequence of feed restriction slaughter weight, chilled carcass weight and dressing out percentage decreased by 141 g (P < 0.001), 22 g (P < 0.001) and 0.8% (P = 0.001), respectively, while the ratio of liver and kidneys to liveweight increased by 0.57% (P < 0.001) and 0.05% (P < 0.001). Cooking loss of musculus longissimus dorsi (MLD) was 1.8% lower (P < 0.05) in H rabbits compared with L and M animals. Cooking loss was 1.6% lower (P = 0.003) in group T than in group O. Due to the restriction, slaughter weight and dressing out percentage decreased by 141 g (P < 0.001) and 0.8% (P = 0.001), respectively. Feeding regime influenced all meat quality parameters except the b* value of meat colour. Rabbits in R group had 0.08 (P < 0.001) lower pH, while 1.1 (P < 0.001) higher L* and 0.7 (P = 0.008) lower a* values resulted lighter colour of MLD. The cooking loss of MLD of R rabbits was 1.2% higher (P = 0.028). Results show that the foetal and suckling nutrient supply exert a long-term effect, affecting also carcass traits and meat quality.