The aim of the present study was to determine the response to the male effect throughout seasonal anoestrus in Serrana breed and to establish the relation between the male effect, artificial photoperiod with long days and nutritional supplementation on reproductive efficiency. Therefore, 80 adult goats were assigned to 2 groups (n=40), the first one was exposed to artificial long days (16L:8D) and the second one was placed under natural photoperiod during 70 days. After this treatment and for 14 days, the groups were subdivided in 2 subgroups (n=40) in order to one of them receive nutritional supplementation 7 days before and after buck introduction on the flock. The artificial light treatment did not have influence (p>0,05) on the male effect response in any of the reproductive parameters and reproductive efficiency. On the other hand, nutritional supplementation only affected (p<0,05) the interval between the day of male introduction and the onset of estrous behaviour, fertility rate and prolificacy rate. These results suggest that the effectiveness of the male effect response did not depend on a previous 3 month artificial long days treatment and suggest that nutritional supplementation may affect male effect response after extending length of supplementation, particularly after male introduction.

Mestrado em Engenharia Zootécnica - Produção Animal - Instituto Superior de Agronomia / Faculdade de Medicina Veterinária