Abstract The aim of this study was to investigate the effect of replacing equine chorionic gonadotropin (eCG) with human chorionic gonadotropin (hCG) and also improving the efficiency of hCG using a slow-release compound (alhydrogel) on the reproductive performance of Afshari ewes after laparoscopic artificial insemination. For this purpose, 48 Afshari ewes (2.5-4 years old with the mean weight of 68±2.5kg and an body condition score of 3.04±0.3 were treated with intravaginal controlled internal drug release (CIDR) for 14 days. The ewes were then divided into 4 groups: the first group: injection of eCG (400IU), 48 hours before CIDR removal (eCGS), the second group: injection of eCG (400IU) combined with alhydrogel, 48 hours before CIDR removal (eCGSR), the third group: injection of hCG (400IU), 48 hours before CIDR removal (hCGS) and the fourth group: injection of hCG (400IU) combined with alhydrogel, 48 hours before CIDR removal (hCGSR). The results showed that there was no significant difference between eCGSR and eCGS treatments in Measured parameters (P>0.05). The lowest pregnancy rate (25%) and fecundity (33%) were recorded in related to the hCGS treatment. However, in the hCGSR treatment, these parameters were increased to the values recorded in eCGSR and eCGS treatments. The results of this study showed that hCG in the presence of slow release compound can be a suitable substitute for eCG in the estrus synchronization protocol based on progesterone and eCG
