Effects of feeding and husbandry factors on reproductive performances of artificially inseminated prepubertal Alpine goats

Abstract

Four trials were conducted on prepubertal alpine goats (n=158) in order to analyse the effects of growth characteristics and feeding level (High or Low) on their fertility after artificial insemination (AI) which was performed at the age of 8 months. Goats were randomly allocated in different groups and received experimental diets from 25 d before, until 21 d after AI, and received the same diet afterward. The mean growth rate was maintained in High fed goats (+54 g/d), while it was depressed in underfed animals (-22 g/d). Just after altering feeding level, blood metabolites changes were in good agreement with previously described evolution, while these evolution were strongly affected during hormonal treatments&nbsp;: blood parameters no longer reflected the animal nutritional status. Restricted goats had an earlier (-2.66 h, P<0.003) pre-ovulatory LH surge when compared to well-fed animals (31.3 h). Differences in fertility among animals are probably due to variability in ovulation time. Furthermore, ovulation rate was higher when LH surge was delayed. Fertility was, on average, positively linked to body weight measured before diets changes. Successful reproduction of young female goats after artificial insemination rely on the control of both husbandry factors (animal grouped according to body weight) and feeding (feeding levels).