Short communication. Melatonin improves the reproductive performance of seasonal anoestrus goats exposed to buck effect during early post-partum

Abstract

The aim of the present study was to determine whether any combination of buck effect and melatonin treatment could improve reproductive performance in Payoya female goats during early postpartum. Forty-four pregnant female goats were used. After birth in spring, they were distributed into two major groups: females submitted to the buck effect (BE, N = 22) or not such effect (NBE, N = 22). In turn, the BE animals were subdivided into: 1) no further treatment (CBE, N = 11) and 2) implanted with melatonin (MELBE, N = 11). And the NBE animals were subdivided into: 3) no further treatment (CNBE, N = 12) and 4) implanted with melatonin (MELNBE, N = 10). Melatonin was implanted 10 days after birth. Oestrus activity was tested daily using entire males from day of birth (D0) in the groups NBE and from D55 after birth in the BE groups. Transrectal ultrasonography was performed 10 days after the detection of oestrus and 45 days after mounting to determine pregnancy. Fecundity, fertility and productivity were higher in MELBE animals compared to CNBE animals (fecundity and fertility: 66.7% vs. 0.0%, and productivity: 0.73 vs. 0.00 kids/female for MELBE and CNBE respectively, p<0.05), and CBE animals (fecundity and fertility: 66.7% vs. 14.3%, and productivity: 0.73 vs. 0.09 kids/female for MELBE and CBE respectively; p<0.05). No significant differences were recorded between the subgroups of the NBE animals. The present results show that exogenous melatonin improves the reproductive performances of early post-partum Payoya does exposed to male effect during the seasonal anoestrus.