Comparative Efficacy of Estrus Induction Protocols Using PGF2α Alone Versus OvSynch and Select Synch in Dairy Cattle in Algeria

Boucif, Ahmed; Abdelmadjid, Noui; Nabi, Mustapha; Salhi, Omar; Khelifi Touhami, Nadjet Amina; Ouchene, Nassim

doi:10.22092/ari.2025.368535.3536

Comparative Efficacy of Estrus Induction Protocols Using PGF2α Alone Versus OvSynch and Select Synch in Dairy Cattle in Algeria

Articles in Press

Document Type : Original Articles

Authors

¹ Institute of veterinary Sciences, University of Tiaret, BP 78, 14000, Tiaret, Algeria

² Institute of Veterinary Sciences, University of Sâad Dahlab Blida 1, BP 270, Blida 09000, Algeria.

10.22092/ari.2025.368535.3536

Abstract

The objective of this study is to evaluate the efficacy of estrus induction protocols based on PGF2α in comparison with an OvSynch-type variant and the Select Synch protocol in terms of reproductive performance in dairy cows in Algerian farms. A total of 105 cows, aged 2 to 5 years, including 39 primiparous and 66 multiparous, of Montbéliarde (66) and Holstein (39) breeds, and gyneco-clinically intact, were divided into three groups. In the first group, cows received two injections of PGF2α at an 11–14-day interval, with a dose of 25 mg per cow of Dinoprost®. In the “OvSynch” and “Select Synch” groups, cows were treated with an injection of 100 μg GnRH (Cystorelin®) on day 0, followed by an injection of 25 mg PGF2α (Dinoprost®) on day 7. Only the “Select Synch” group received a second injection of 100 μg GnRH on day 9. Cows were inseminated based on observed estrus at the end of each protocol. Pregnancy was diagnosed via ultrasound at day 30 post-AI and confirmed by transrectal palpation at day 45. Estrus response rates (74 %, 48.6 %, 40 %; P > 0.05) and average pregnancy rates (54.4%, 31.4%, 28.6%; P < 0.005) were recorded, corresponding to conception rates of 73.1%, 65%, and 71.4% (P > 0.005) for groups 1, 2, and 3, respectively. Being simple, cost-effective, and efficient, the prostaglandin-only protocol is recommended for cows inseminated based on observed estrus. Protocols combining GnRH with PGF2α allow estrus synchronization, reducing the need for daily estrus detection and additional handling.

Keywords