Comparison between the effect of human menopausal gonadotropin and equine chorionic gonadotropin on reproductive efficiency of Shami goats outside the breeding season

Abstract

This study aimed to eliminate progestogen pessaries from estrus induction programs during the nonbreeding season in Shami goats.

Thirty multiparous Shami goats were randomly allocated into three equal treatment groups. Vaginal sponges have been inserted for 14 days the first and second group. Follicular development was induced in the control and second group with 750 IU eCG and 25 IU hMG along with sponges withdrawal, respectively, and in the third group with 25 IU hMG only. All goats were artificially inseminated at fixed time (24h after hCG administration) with a fresh diluted semen collected using an electroejaculator just before insemination time. An ultrasound scanner equipped with a linear transducer probe with a frequency of 7.5 MHz was used to monitor ovarian follicles for three consecutive days, starting from gonadotropin administration, and to diagnose pregnancy at 35 d post A.I. There were no statistical differences (p>0.05) in the mean number of small follicles on the first day between the hMG, hMGSP and eCG groups. No medium and large follicles were recorted in the three groups. After 24 and 48 hours of gonadotropin administration, there were no significant differences (p>0.05) in the mean numbers small, medium or large, among the three groups. No statistical differences (p>0.05) were observed either in follicular growth rate (24 or 48 hours after hormonal treatment) or in ovarian follicle diameter (day of hCG injection) between the eCG and hMG groups. No statistical differences (P>0.05) were reported in pregnancy rate after treatment with hMG with progestogen or without it compared to eCG. Estradiol concentrations did not differ significantly (P>0.05) between the three groups. It may be concluded that hMG may alone without progestogens as an alternative to traditional programs based on eCG and progestogens to induction of estrus and follicular development in Shami goats during the nonbreeding season.