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.
Effect of nutritional status of rabbit kits on their productive performance, carcass and meat quality traits
BIANCHI, MAURIZIO;CAVANI, CLAUDIO;PETRACCI, MASSIMILIANO;
2011
Abstract
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
