EFFECT OF BIRTH WEIGHT AND LITTER SIZE ON GROWTH AND MORTALITY IN RABBITS

Abstract

Two experiments were performed with Pannon White rabbits. In the first experiment 50 litters were formed with 6, 8 or 10 rabbits of different birth weight in equal ratios (n = 380, between 39 and 70g). In the second experiment 60 litters of 6, 8 or 10 rabbits were formed (n = 456), each litter consisting of rabbits of a single weight group only (small: 39 to 43g; medium: 53 to 56 g; large: 63 to 70 g). With increasing birth weight and decreasing litter size, mortality in the suckling rabbits decreased and daily weight gain of kits and weight of rabbits up to 10 weeks of age increased significantly. These effects were weaker in experiment 2. In the extreme groups used in the experiments (10 small kits and 6 large kits) the following results were obtained: mortality between birth and 21 days was 35.3 and 8.1 % in experiment 1 and 18.0 and 5.6 % in experiment 2, daily weight gain of kits between birth and 21 days was 9.2 and 18.5 g in experiment 1 and 10.8 and 16. 7 g in experiment 2, and body weight at 10 weeks of age was 1.90 and 2.58 kg in experiment 1 and 2.11 and 2.45 kg in experiment 2. In conclusion, intra-litter homogenisation of birth weight markedly reduced mortality in small rabbits and standard deviation in live weight within litters.