Effectiveness of Specific Hormonal Protocols on Uterine Involution and Ovarian Cyclicity in Early Postpartum Egyptian Buffaloes.

Rapid uterine involution and early resumption of ovarian cyclicity are essential for improving reproductive efficiency in postpartum buffaloes. This study evaluated the effects of different hormonal protocols administered during early postpartum on uterine involution, ovarian activity, and reproductive performance in multiparous Egyptian buffaloes. Particular attention was given to the timing of equine chorionic gonadotropin (eCG) administration, as its application around Day 14 postpartum has been relatively less explored in buffaloes despite coinciding with early uterine recovery and emerging follicular activity. Ninety buffaloes were allocated into five groups receiving gonadotropin-releasing hormone (GnRH), eCG, or their combinations with prostaglandin F2α, in addition to a control group. Reproductive performance, ovarian activity assessed by ultrasonography, and serum progesterone concentrations were monitored during the early postpartum period. Buffaloes treated with eCG showed shorter uterine involution periods, reduced days open, and higher pregnancy rates compared with untreated controls. Hormonal treatments, particularly eCG-based protocols, enhanced ovarian cyclicity, as reflected by improved follicular development, corpus luteum formation, and increased progesterone concentrations. In conclusion, the most favorable reproductive outcomes were achieved when eCG was administered alone or in combination with GnRH and prostaglandin F2α during the early postpartum period.