Female sexual behavior is inhibited by short- and long-term food restriction

In female musk shrews, sexual receptivity is not restricted to the periovulatory period. Several copulatory bouts that occur over a number of days are required to induce the first ovulation. We tested the hypothesis that food restriction would have a minimal impact on female musk shrew sexual behavior because mating behavior may be uncoupled from ovulation in this species. Three testing conditions were used. In the first study, food-restricted females were maintained at their weaning day weight for 17 days. Food restriction resulted in a significant reduction in the number of females that allowed males to mount, intromit, or ejaculate compared with ad lib-fed controls. In the second experiment, sexually experienced females that were food-restricted for 2 weeks also displayed reduced sexual behavior compared to that in ad lib-fed controls. In the last study, we examined the effects of short-term food fluctuations on sexual behavior. Females food-restricted for 48 h showed reduced mating behavior compared to that in ad lib-fed controls. This was reversed after 24 h of refeeding. These studies show that, even under conditions where copulation does not lead to pregnancy, small reductions in food availability can inhibit female sexual behavior.