Objective: The aim of this study was to monitor the ovarian response and conception rate following estrous synchronization using CIDR, Ovsynch and double prostaglandin F2
protocols in Egyptian buffalo heifers. Material and methods: A total of 80 cyclic buffalo heifers
were divided into four equal groups: CIDR (intravaginal progesterone releasing device, EAZI-BREEDTM CIDR®), Ovsynch (GnRH, PGF2
, GnRH injections), PGF (double PGF2
doses) and control. Timed artificial insemination (TAI) was performed in all heifers. All animals were examined using ultrasound and blood samples were collected for measurement of progesterone. Results: A new follicular wave occurred
earlier in the Ovsynch and PGF groups than in the CIDR group (p < 0.05). The mean diameter of the ovulatory follicle was smaller in the CIDR group than in the Ovsynch and PGF groups (p < 0.05). The ovulation rate was 100% in the CIDR group, 75% in the Ovsynch group and 70% in the PGF group. In the control group a lower pregnancy rate (20%) was determined in than in the CIDR (35%), Ovsynch (40%) and PGF (35%) groups. Progesterone concentrations were numerically higher in pregnant heifers of the CIDR group but the difference was non-significantly compared to the Ovsynch, PGF and control groups (p > 0.05). Conclusion and clinical relevance: EAZIBREEDTM CIDR®, Ovsynch-based TAI and PGF protocols were effective in synchronizing oestrus and resulted in nearly similar pregnancy rates
in Egyptian buffalo heifers.