Effects of nutritional stress induced by short-term fasting on reproductive performance of rabbit does

An increasing body of evidence suggests that in different speciescaloric restriction induced by short-term fasting (STF) negativelyinfluences the reproductive function by disrupting the gonadotropicaxis. As far as we know, however, the reproductive adaptations toSTF have never been tested on rabbits and, due to strikinginterspecies differences, they need to be verified in detail. To assessthe impact of metabolic stress on reproductive performance, 80multiparous lactating and non-lactating females were randomlyassigned to either ‘‘control’’ or ‘‘fasting’’ groups. In the first group,the does were fed ad libitum while in the other the animals werefasted for 24 h the day before AI. In this group, the does were re-feed 2 hours before artificial insemination (AI). AI was performed onday 11 (lactating does) or on day 32 post partum (non-lactatingdoes) following GnRH injection to induce ovulation. In lactatingdoes, the 24-h long fasting markedly reduced fertility by almost 50%(P<0:05) but not the number of pups born alive. By contrast, thesame metabolic stress had no effect when applied to non-lactatingdoes as both reproductive parameters and ovarian indexes (numberof CL, embryos) were similar to control. In summary, these resultssuggest that short-term caloric deprivation regulate differently thereproductive activity of rabbits depending on the metabolic statusand energy reserves.