Pregnant mare serum gonadotropin (PMSG) in estrus synchronization and multiple ovulation in ewes

Authors

1 M. Auezov South Kazakhstan Research University, Тauke khan St. 5, 160012, Shymkent, Kazakhstan

2 Kazakh Scientific Research Institute of Animal Husbandry and Food Production LLP, Zhandosova St. 51, Almaty, Kazakhstan

10.22124/cjes.2026.10079

Abstract

The aim of this study was to evaluate the effects of different doses of pregnant mare serum gonadotropin (PMSG, eCG) on estrus synchronization and the ovulatory response in ewes. The proposed experimental design included 60 clinically healthy ewes divided into three groups of 20 animals each. Following a 12-day progestogen treatment, the control animals received physiological saline, while the ewes in the first and second experimental groups were administered 500 and 750 IU of PMSG, respectively. The modelled results showed that estrus occurred in 60.0%, 90.0%, and 95.0% of the animals, respectively (p = 0.008). The interval from device removal to the onset of estrus decreased from 51.8 ± 6.7 h in the control group to 39.6 ± 5.4 and 34.2 ± 4.9 h in the experimental groups (p < 0.001), while the number of ovulations increased from 1.25 ± 0.44 to 1.85 ± 0.67 and 2.45 ± 0.76, respectively (p < 0.001). Pregnancy rates were 50.0%, 80.0%, and 75.0%, respectively (p = 0.092). The 750 IU dose produced the most pronounced ovulatory response but provided no advantage in pregnancy rate compared with the 500-IU dose. Within the framework of the model, the 500-IU dose demonstrated the most balanced combination of estrus synchronization, ovulatory response, and reproductive efficiency.

Keywords

References

Abecia, JA, Forcada, F & González-Bulnes, A 2012, Hormonal control of reproduction in small ruminants. Animal Reproduction Science, 130(3–4): 173–179. DOI: 10.1016/j.anireprosci.2012.01.011.
Cognie, Y 1999, State of the art in sheep–goat embryo transfer. Theriogenology, 51(1): 105–116. DOI: 10.1016/S0093-691X(98)00235-0.
De Rensis, F & López-Gatius, F 2014, Use of equine chorionic gonadotropin to control reproduction of the dairy cow: A review. Reproduction in Domestic Animals, 49(2): 177–182. DOI: 10.1111/rda.12268.
Driancourt, MA 2001, Regulation of ovarian follicular dynamics in farm animals: Implications for manipulation of reproduction. Theriogenology, 55(6): 1211–1239. DOI: 10.1016/S0093-691X(01)00479-4.
González-Bulnes, A, Baird, DT, Campbell, BK, Cocero, MJ, García-García, RM, Inskeep, EK et al. 2004, Multiple factors affecting the efficiency of multiple ovulation and embryo transfer in sheep and goats. Reproduction, Fertility and Development, 16(4): 421–435. DOI: 10.1071/RD04033.
Marquezini, GHL, Mercadante, VRG, Olson, KC, Jaeger, JR, Perry, GA, Stevenson, JS et al. 2013, Effects of equine chorionic gonadotropin on follicle development and pregnancy rates in suckled beef cows with or without calf removal. Journal of Animal Science, 91(3): 1216–1224. DOI: 10.2527/jas.2012-5382.
Menchaca, A & Rubianes, E 2004, New treatments associated with timed artificial insemination in small ruminants. Reproduction, Fertility and Development, 16(4): 403–413. DOI: 10.1071/RD04037.
Pérez, MM, Veronez, LC, Cordeiro, FA, de Castro Figueiredo Bordon, K, Arantes, EC, Munari, C et al. 2025, An alternative in vitro methodology for the quality control of equine chorionic gonadotropin in commercial products. ACS Omega, 10(7): 7211–7219. DOI: 10.1021/acsomega.4c10780.
Wei, SC, Gong, ZD, Zhao, HW, Liang, HQ, Lai, LJ & Deng, YY 2016, Equine chorionic gonadotropin influence on sheep oocyte in vitro maturation, apoptosis, and follicle-stimulating hormone receptor and luteinizing hormone receptor expression. Genetics and Molecular Research, 15(4): gmr15049162. DOI: 10.4238/gmr15049162.
Wildeus, S 2000, Current concepts in synchronization of estrus: Sheep and goats. Journal of Animal Science, 77(E-Suppl): 1–14.
Caspian Journal of Environmental Sciences
Volume 24, Issue 4
October 2026
Pages 1311-1315

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