Influencia del uso de GNRH (hormona liberadora de gonadotropina) en protocolos convencionales y su incidencia en la tasa de concepción en ganado cebú

Jorge Luis Zambrano-Andrade; Adrián Fernando Chávez-Rivas

doi:10.56124/allpa.v8i16.0134

Authors

Zambrano-Andrade Jorge Luis Escuela Superior Politécnica Agropecuaria de Manabí Manual Félix López. Calceta, Ecuador. https://orcid.org/0009-0005-6314-7258
Chávez-Rivas Adrián Fernando Escuela Superior Politécnica Agropecuaria de Manabí Manual Félix López. Calceta, Ecuador. https://orcid.org/0009-0001-2524-7988

DOI:

https://doi.org/10.56124/allpa.v8i16.0134

Keywords:

GnRH, conception rate, estrus synchronization, preovulatory follicle, Zebu cattle

Abstract

Abstract

This study evaluated the influence of gonadotropin-releasing hormone (GnRH) on conventional estrus synchronization protocols and its effect on conception rates in Zebu cows. The research was conducted in Patricia Pilar, Buena Fe canton, Los Ríos province, Ecuador, using a comparative experimental design with 313 females distributed into three groups: a control group without GnRH (T0), a standard treatment group with 100 µg (2 ml, T1), and an experimental treatment group with 150 µg (3 ml, T2). The following variables were evaluated: conception rate, preovulatory follicle size, reproductive status, and correlations between estrus, follicle size, and pregnancy diagnosis. Data were analyzed using ANOVA, Tukey's test (p ≤ 0.05), and Pearson's correlation. The results showed a favorable dose-response trend: the conception rate increased from 37.5% (T0) to 44.1% (T1) and 48.1% (T2). With 3 ml of GnRH, larger preovulatory follicles (15.1 mm) and a higher proportion of cycling females (40.6%) were obtained, with positive correlations between follicular size and the presence of estrus (r = 0.370) and pregnancy (r = 0.528). These results confirm that increasing the GnRH dose promotes ovarian maturation and improves reproductive indicators in Zebu cattle.

Keywords: GnRH, conception rate, estrus synchronization, preovulatory follicle, Zebu cattle.

Downloads

Download data is not yet available.

References

Bó, G. A., Macagno, A., Mata, J. D. L., Vera Cedeño, A., Huguenine, E., Tschopp, J. C., & Menchaca, A. (2023). Protocolos de IATF: desde la comprensión de la dinámica folicular ovárica a las restricciones actuales y futuras de su uso. L Jornadas Uruguayas de Buiatría. Simposio de Reproducción animal. Paysandú, Uruguay. https://bibliotecadigital.fvet.edu.uy/bitstream/handle/123456789/3284/JB2023_123-138.pdf?sequence=1&isAllowed=y

Butler, A., Butler, H., Cesaroni, G., Alberio, R., Perez Wallace, S., García Guerra, A. (2020). Treatment with gonadotrophin releasing hormone at the time of AI in beef heifers that fail to express oestrus after an estradiol-based synchronisation protocol improves pregnancies per AI. Reprod Fertil Dev, 32(2), 208. https://doi.org/10.1071/RDv32n2Ab163

Chauvin, S., Cohen Tannoudji, J., & Guigon, C. J. (2022). Estradiol Signaling at the Heart of Folliculogenesis: Its Potential Deregulation in Human Ovarian Pathologies. International journal of molecular sciences, 23(1), 512. https://doi.org/10.3390/ijms23010512

D’Onofrio, G., Herring, A. A., Perrone, J., Hawk, K., Samuels, E. A., Cowan, E., ... & Fiellin, D. A. (2024). Extended-release 7-day injectable buprenorphine for patients with minimal to mild opioid withdrawal. JAMA Network Open, 7(7), e2420702-e2420702. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2820859#google_vignette

García Díaz, R., Scull Satorre, J., Sarria Sotomayor, Y. Pérez Bello, A., & Hernández Barreto, M. (2018). Comportamiento reproductivo de los genotipos Cebú y 5/8 Cebú x 3/8 Simmental en la región central de Cuba. Revista de Producción Animal, 30(2), 44-51. http://scielo.sld.cu/scielo.php?script=sci_arttext&pid=S2224-79202018000200007&lng=es&tlng=es

Vázquez Loaiza, M., & Molina Coto, R. (2021). Métodos de reproducción y parámetros reproductivos de cebuínos con registro genealógico en Costa Rica. Agron. Mesoam, 19-33.

Guzmán A., F. V., Andrade M., L. B., Pita V., F. E., Matute V., R. V., Tríbulo, H., & Caicedo, J. A. (2019). Efecto del diámetro del folículo preovulatorio en el momento de la IATF y de la expresión de estro sobre la tasa de preñez en vacas Nelore con cría al pie. Dominio de las Ciencias, 5(1), 733-773.

Hassanein, E. M., Szelényi, Z., & Szenci, O. (2024). Gonadotropin-releasing hormone (GnRH) and its agonists in bovine reproduction I: structure, biosynthesis, physiological effects, and its role in estrous synchronization. Animals, 14(10), 1473. https://doi.org/10.3390/ani14101473

Klein, B. (2019). Fisiología veterinaria. 5ᵃ ed. Blacksburg. Virginia, EEUU. https://www.sciencedirect.com/book/9780323552271/cunninghams-textbook-ofveterinary-physiology

Madureira G, Consentini C, Motta J, Drum J, Prata, A, Monteiro P, Melo LF, Gonçalves J, Wiltbank M, Sartori, R. (2020). Progesterone-based timed AI protocols for Bos indicus cattle II: Reproductive outcomes of either EB or GnRH-type protocol, using or not GnRH at AI. Theriogenology, 145, 86-93.

Oosthuizen, N., Goncalves, L. M., Burato, S., Smith, M. S., Harvey, K. M., Lamb, G. C., & Fontes, P. L. (2025). Comparison of different GnRH compounds on fertility outcomes in ovulation synchronized and presynchronized beef cows. Frontiers in Animal Science, 6, 1502984. https://www.frontiersin.org/journals/animal-science/articles/10.3389/fanim.2025.1502984/full

Rodríguez, AM, Maresca, S., López-Valiente, S., Bilbao, MG, Moran, KD, Bartolome, JA, ... y Long, NM (2023). Comparación de los protocolos CO-Synch de 7 días y estradiol de 8 días para la sincronización del estro y la inseminación artificial programada en vacas Bos taurus amamantadas. Theriogenology, 200, 70-76. https://doi.org/10.1016/j.theriogenology.2023.02.003

Tacuri Mallqui, K. M. (2024). Rendimiento ovárico de folículos antrales según estado reproductivo en vacas criollas faenadas en el matadero de Quicapata. Universidad Nacional de San Cristóbal de Huamanga. Ayacucho, Perú. https://repositorio.unsch.edu.pe/items/1f0a01f9-153e-4190-a7b2-dd6367ddcf4b

Toapanta Aviles, B. R. (2023). Determinación del efecto del proestro prolongado sobre el tamaño del folículo dominante y tasa de preñez en bovinos Indicus con Iatf. Escuela Superior Politécnica de Chimborazo. Riobamba. https://dspace.espoch.edu.ec/items/1fbe11c4-77c0-439a-a04e-731da3ac5549