Añó Perelló, AinaSantos Jiménez, ZurisadayEncinas Cerezo, TeresaGonzález de Bulnes López, AntonioMartínez Ros, PaulaUCH. Departamento de Producción y Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los AlimentosProducción Científica UCH 20202021-04-272021-04-272020-07-16Año-Perello, A., Santos-Jimenez, Z., Encinas, T., Martinez-Ros, P., Gonzalez-Bulnes, A. (2020). Use of GnRH for synchronization of the follicular wave in assisted reproductive technologies in sheep: a preliminary study. Animals, vol. 10, i. 7 (16 jul.), art. 1208. DOI: https://doi.org/10.3390/ani100712082076-2615 (Electrónico).http://hdl.handle.net/10637/12502Este artículo se encuentra disponible en la siguiente URL: https://www.mdpi.com/2076-2615/10/7/1208Este artículo pertenece al número especial "New technologies in ruminant breeding".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 o er a time- and cost-e cient protocol for inducing follicular turnover and synchronizing a new follicular wave at any stage of the estrous cycle.application/pdfenopen accessEstro.Estrus.Sheep - Generative organs.Ovejas - Reproducción asistida.Sheep - Reproductive technology.Reproducción asistida en los animales.Hormonas sexuales.Hormones, Sex.Ovejas - Aparato genital.Reproductive technologie in animals.Artículohttps://doi.org/10.3390/ani10071208https://creativecommons.org/licenses/by-nc-nd/4.0/deed.es