Prenatal factors affecting the probability of survival between birth and weaning in rabbits

Abstract

The aim of this study was to analyse the relationships between kit birth weight and litter size with kit survival from birth to weaning, and to estimate the effects of place of birth, nest quality, cannibalism, lactation, parity order, season and sex. A total of 1696 kits from 82 females of the ITLEV2006 synthetic line were used in this study. A logistic regression was performed. Kit birth weight was directly related to the probability of the kit’s survival from birth to weaning, and increasing birth weight by one gram increased the likelihood of kit survival by 8% to 10% (P<0.001). In line with the decrease in birth weight of kits as the number of kits at birth increases, litter size showed a negative relationship to the probability of survival from birth to weaning, and increasing the litter by one kit at birth decreased the probability of survival of the kits by 5% to 9% (P<0.05). Regarding effects, cannibalism events in the litter decreased the probability of survival of the kits in the first week of life (P<0.01). Being born in the cage decreased the probability of survival of the kits from birth to weaning, and kits born outside the nest had a lower chance of survival than those born inside the nest (P<0.01). The order of parturition had a positive effect on probability of survival of the kits from 5 days of age to weaning (P<0.05). Female kits had a lower chance of survival than male kits, but only until 5 days of age (P<0.01). The lactation status displayed a negative effect on the probability of survival of the kits in the first week of life, and kits gestated in lactating females had a lower chance of survival than those gestated in non-lactating females (P<0.05). In conclusion, the probability of kit survival in the first days after parturition was affected mainly by its weight at birth, litter size, cannibalism events, place of birth of kit, parity order, sex and lactation status, while the probability of kit survival at weaning was directly related to its weight at birth, litter size, place of birth of kit and parity order.