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Updated: Dec 13, 2025
Isolation of Small Preantral Follicles from the Bovine Ovary Using a Combination of Fragmentation, Homogenization, and Serial Filtration
Published on: September 27, 2022
Use of GnRH for Synchronization of the Follicular Wave in Assisted Reproductive Technologies in Sheep: A Preliminary
Aina Año-Perello1, Zurisaday Santos-Jimenez2,3, Teresa Encinas3
1Departamento de Produccion y Sanidad Animal, Facultad de Veterinaria, Universidad Cardenal Herrera-CEU, CEU Universities, C/ Tirant lo Blanc, 7. 46115 Alfara del Patriarca Valencia, Spain.
Abstract:
The present study aimed to set up a short-term protocol for synchronization of follicular wave emergence in sheep, concomitant with estrus synchronization, which would improve ovarian response in assisted reproductive technologies. Administration of a single GnRH dose, concomitant with the insertion of a progesterone-loaded CIDR device, caused regression of gonadotrophin-dependent follicles ≥4 mm in all the GnRH-treated sheep and in around 80% of the controls treated only with CIDR (p < 0.05). Similar percentages of ewes lost all follicles (around 70%) or only the largest one (around 30%) in both groups. Hence, 54.1% and 70% of the sheep lost all large follicles and initiated a new follicular wave in the control and GnRH groups, respectively (p < 0.05). The remaining sheep showed follicles that were still not dependent of luteinizing hormone (LH). So, in fact, all the sheep had non-dominant follicles after treatment. In conclusion, a treatment including GnRH at CIDR insertion would offer a time- and cost-efficient protocol for inducing follicular turnover and synchronizing a new follicular wave at any stage of the estrous cycle.
