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

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

Physicochemical properties and sensory profile of some breeds of rabbits in Algeria

The objective of this study was to compare physicochemical traits and sensory profile of meat from rabbits of both sexes belonging to two genotypes, local population and new line (ITELV 2006) which exhibited better characteristics due to its genetic potential. A total of 60 rabbits at 90 days of age were used in the experiment. At slaughter, meat physicochemical and sensory characteristics were measured on Longissimus lumborum muscle. Differences related to genotype were found in most of the physicochemical characteristics studied like Cooking Losses (P  0.05). Interestingly, no relevant differences were found between meat from male and female rabbits in all the variables studied (P > 0.05). It was concluded that meat quality was mainly affected by genotype. Thus, the new line exhibited good physicochemical characteristics compared to the local one. This study is the first to analyse and compare the physicochemical and sensory properties of Algerian rabbit meat.This work was supported by the Algerian Ministère de l'Enseignement Supérieur et de la Recherche ScientifiquePeer reviewe

Genetic Analyses of Rabbit Survival and Individual Birth Weight

Genetic parameters of kit survival traits and birth weight were estimated on ITELV2006 synthetic line aimed at improving kit survival using a multiple trait linear and threshold model. Data on 1696 kits for survival at birth and at weaning, as well as individual birth weight and litter size were analysed. Genetic effects of kit survival traits and birth weight were estimated based on threshold and Gaussian models, respectively, using a Bayesian approach. The statistical model included, as fixed effects, parity, lactation status, season of farrowing, nest status, cannibalism in kit, place of kit&rsquo;s birth in the cage and gender, and adjustment for litter size. Posterior means of heritabilities for direct genetic effects of survival at birth and the entire nursing period, as well as birth weight, were 0.018, 0.023, and 0.088, respectively, and were increased when adjusted for litter size to 0.021, 0.027 and 0.146. Genetic correlation between survival traits was zero. Therefore, these traits can be treated genetically as different traits. Genetic correlation between direct effects of survival at birth and birth weight showed positive, but low, value (+0.134) and was increased to +0.535 when the traits were adjusted for litter size. No genetic correlation was found between survival at weaning and birth weight. These magnitudes of genetic parameter estimates suggested that there is substantial potential for the genetic improvement of kit survival at birth through selection for birth weight