β-carotene supplementation increases progesterone concentration and glutathione peroxidase activity following alternative progesterone primed oestrous synchronization protocol in goats

The present study evaluated the effect of β-carotene supplementation and oestrous synchronization protocol on ovarian activity and fertility of Saanen does during the breeding season. The supplemented group received 100 mg β-carotene during the breeding and all does were synchronised with Controlled Internal Drug Release dispenser (CIDR) and injected with cloprostenol at CIDR withdrawal. One group of does were injected with 300 IU of eCG, while in another group bucks wearing aprons were introduced at CIDR withdrawal. Does were artificially inseminated twice (48 and 60 h) with fresh undiluted semen. The onset and duration of oestrus, progesterone, oestrdiol-17β and glutathione peroxidase activity, oestrous response and conception rate were analysed. Synchronization protocol did not affect response to oestrus, onset and duration of oestrus and oestradiol-17β concentration. The male presence group had significantly higher conception rate (97%) than the eCG (72%) group. β-carotene supplemented group had higher progesterone concentration and glutathione peroxidase activity. Supplemental β-carotene during the breeding period therefore, could play an important role on establishment of pregnancy due to high progesterone concentration and glutathione peroxidase activity. Inclusion of male effect in progesterone based oestrous synchronization protocol improves conception rate. Therefore, male effect can be used as an alternative to equine chorionic gonadotropin in progesterone based oestrous synchronization protocols especially, where drugs for oestrous synchronization are not affordable.The Office of International Research, Education and Development (OIRED); the University of Pretoria; the United States Agency for International Development under the CGIAR Fund and the predecessor fund the Food Security and Crisis Mitigation II grant.am2020Animal and Wildlife Science