INFLUENCES OF ENVIRONMENT ON THE DEVELOPMENT AND LIFETIME REPRODUCTIVE PERFORMANCE IN DOMESTIC RABBIT FEMALES

摘要

Environmental insults of different nature and intensity, such as fluctuation in the air temperature, which can affect access to food, its quality and diseases, are a reality in any livestock system. This is much more important when the insults occur in early life, conditioning the development and adult life of animals. In ecology, for instance, it is widely accepted that high quality offspring are more reactive against predators, occupy better territories and find more mates, resulting in longer lives and greater fitness. It is also a given that adults exposed to famine or disease as juveniles have shorter lives and produce fewer offspring. To determine whether the environment influences the development and lifetime reproductive performance of rabbit females, we designed an experiment combining two factors: nest and pubescent development. Nest development was measured by recording the average daily gain of 864 females during suckling and during their pubescent life (63 to 184 d old), and body development was conditioned by providing animals a high-energy control (C) or a fibre-rich (F) diet. However, in the course of the study, 191 of the 864 pubescent females were exposed to rabbit haemorrhagic disease (RHD). This unexpected environmental insult was considered as a third experimental factor influencing the reproductive performance of rabbit females. Contrary to expectation, fast suckling gain impairs reproductive lifespan, resulting in fewer newborn kits produced in a female lifetime. Although females on diet F lived 37 d longer than females on diet C, this difference was only perceived in their pubescent life. In addition, the exposure to RHD interacted with suckling gain (SG). Exposed females with a fast SG produced more kits as adults, but in the absence of the virus, high SG females produced fewer newborn kits. These results open new insights into the management of future breeders during nesting and pubescent life.