Effect of genotype and some non-genetic factors on weaning weight in rabbits

Abstract

The rabbit meat producers have a strong desire to improve productivity in order to maximize on financial gains. There has been a deliberate move to target improved weaning weight, which is thought to be a critical component in influencing total meat yield and economic returns. However, it has been acknowledged that weaning weight is partly influenced by individual kit genetic potential at the same time its overwhelmed by various non genetic factors. In this respect, weaning weights a complex character which reflects the influence of many biological processes namely fertility, maternal instinct, growth and viability. For the purpose of increasing production, it is reasonably to suggest that the complex inter-relationship among known various non genetic factors that influence weaning weight and the degree of their interactive effects need to be ascertained and understood in different production systems. While, genotype is a major contributor to weaning weight, environmental, nutritional and management practices also play significant roles in influencing weaning weight. There are several known environmental factors that influence weaning weight and these include feeding practices, birth weight, parity order, sex of kits, management, etc. The rabbit producers’ attention to the aforementioned factors is likely to improve weaning weight at enterprise level. It is important to note that selection for increased litter size have an adverse effect on average litter birth weight which subsequently reflects on weaning weight. The enhanced prolificacy in does has resulted in an increase in within litter variation and a larger number of kits born light. From the farmer’s performance point of view, genetic diversity utilization in crossbreeding has been the focus in improving weaning weight in commercial rabbit meat production. However, the complementary role played by nutritional status in optimization of performance in selected genotypes has been tremendous in the past two decades. Crossbreds have performed at levels consistent with different targeted rabbit meat market expectations. Generally, it is pronounced that improved nutritional regime and patterns for lactating does and their suckling kits had a positive effect on weaning weight. On the other hand, unbalanced parity structure and distribution in rabbit enterprise results in unreasonable variation in weaning weight, which impacts negatively on subsequent kits management after weaning. The purpose of this review is to discuss the influence of genotype and some non-genetic factors (litter size, birth weight, parity) on weaning weight in rabbits.