Effect of restricted feeding on productive and carcass traits of rabbits

Abstract

The study examined the age-dependent feed restriction on growing rabbits' growth and carcass traits. Three groups of weaned rabbits (5 weeks of age, n=243)) were established: AL=control group: ad libitum feeding during the whole fattening period (n=81), RF65 group: 65% of the feed consumption of AL during the first two weeks after weaning, 80% in the third, 100% in the fourth week and ad libitum afterward (n=81), RF70 group: 70% in the first two weeks, 80% in the third, 100% in the fourth week and ad libitum till slaughtering (n=81). Feed consumption was in line with the planned level during the feed restriction period. After finishing the restriction at 100%, the feed consumption increased rapidly, and it was higher between 9 and 11 weeks of age than that of the AL group (P<0.001). Daily weight gain of restricted groups was lower between 5 and 7 weeks of age (47.7 vs. 28.9 and 25.2 g/day in AL, RF70, and RF65, respectively, P<0.001). The differences in body weights were highest at seven weeks of age, and later the differences decreased (body weight at 11 weeks, AL: 2710 g, RF65: 2637 g, RF70: 2655 g, P <0.05). In the first week, the feed conversion rate was better in the AL group, while between 7 and 10 weeks of age, it was better in the restricted groups (P<0.001). Significant differences were found in mortality but independent of treatment. The feed restriction had a slight effect on carcass traits. The weight of the fore part of the carcass was higher in the AL group (P=0.053), while the liver was heavier in the restricted rabbits (84.2 vs. 80.1 g, P=0.388). The perirenal fat content was the lowest in RF65 rabbits (16.9 g) and the highest in the AL group (21.6 g, P<0.05). A stricter and then milder feed restriction after weaning and ad libitum feeding in the final fattening stages could be preferred.