Acta Vet. Brno 2022, 91: 125-131

The effect of supplementation of follicle-stimulating hormone (FSH) into the Ovsynch protocol to increase the pregnancy rate in cyclic lactating dairy cows

Gulnaz Yilmazbas-Mecitoglu1, Abdulkadir Keskin1, Ebru Karakaya-Bilen2, Umut Taşdemir3, Ahmet Gumen1

1University of Bursa Uludag, Faculty of Veterinary Medicine, Department of Obstetrics and Gynaecology, Bursa, Turkey
2University of Siirt, Faculty of Veterinary Medicine, Department of Obstetrics and Gynaecology, Siirt, Turkey
3Aksaray University, Faculty of Veterinary Medicine, Department of Artificial Insemination, Aksaray, Turkey

Received September 23, 2021
Accepted February 1, 2022

The aim of this study was to determine the effects of the follicle stimulating hormone (FSH) supplemented in the Ovsynch protocol on pregnancy per timed artificial insemination (P/TAI) in cyclic dairy cows. All cows (n = 383) included in the study received the Ovsynch protocol. The cows in FSH3 (n = 92), FSH4 (n = 88), and FSH3&4 (n = 91) were administered 20 mg FSH on day 3, or day 4, or both on days 3 and 4 of the protocol, respectively, whereas the control group (n = 112) did not receive any FSH treatment. The mean follicle number at TAI and ovulation number after TAI were similar among the FSH groups. However, the mean follicular size was smaller (~14.9 mm, P = 0.02) in FSH4 compared to the other groups (~15.9 mm). Pregnancy/TAI of the FSH4 group on day 31 (59.1%) and day 62 (53.4%) was higher than those of other groups on day 31 (45.5% in control, 45.7% in FSH3, and 46.2% in FSH3&4) and day 62 (42.9% in control, 43.5% in FSH3, and 40.7% in FSH3&4), but the difference was non-significant. Likewise, FSH4 (62.7%) had more (P = 0.05) P/TAI than the other groups (48.6% in control, 47.7% in FSH3, and 49.4% in FSH3&4) in synchronized cows. The cows which responded to the first gonadotropin-releasing hormone (GnRH) of Ovsynch in the FSH4 group (64.8%) had higher (P < 0.02) P/AI rate than the responding control cows (44.6%). We concluded that application of FSH on day 4 in cyclic cows which were responsive to the Ovsynch protocol can yield higher pregnancy rates, but more studies are needed to better demonstrate this potential effect.


25 live references