Seventy years of progestagen treatments for management of the sheep oestrous cycle: where we are and where we should go
Antonio Gonzalez-Bulnes
A B G , Alejo Menchaca C D , Graeme B. Martin E and Paula Martinez-Ros F
+ Author Affiliations
- Author Affiliations
A Departamento de Reproduccion Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Avenida, Puerta de Hierro, s/n, 28040, Madrid, Spain.
B Departamento de Toxicologia y Farmacologia, Facultad de Veterinaria, Universidad Complutense de Madrid, Ciudad Universitaria, s/n, 28040, Madrid, Spain.
C Instituto de Reproducción Animal Uruguay, Fundación Instituto de Reproduccion Animal del Uruguay, Camino Cruz del Sur 2350, Montevideo, Uruguay.
D Programa de Posgrado, Facultad de Veterinaria, Universidad de la República, Avenida Lasplaces, 1550, Montevideo, Uruguay.
E Institute of Agriculture, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
F Departamento de Produccion y Sanidad Animal, Facultad de Veterinaria, Universidad Cardenal Herrera- Centro de Estudios Universitarios (CEU), CEU Universities, C/ Tirant lo Blanc, 7. 46115 Alfara del Patriarca Valencia, Spain.
G Corresponding author. Email: bulnes@inia.es
Reproduction, Fertility and Development 32(5) 441-452 https://doi.org/10.1071/RD18477
Submitted: 22 November 2018 Accepted: 10 August 2019 Published: 24 January 2020
Abstract
Management of the ovine oestrous cycle is mainly based on the use of exogenous hormones to mimic or enhance (progesterone and its analogues) or manipulate (prostaglandin F2α and its analogues) the activity of the corpus luteum, combined with the application of other hormones mimicking the pituitary secretion of gonadotrophins (e.g. equine chorionic gonadotrophin). These protocols have been applied without major change for decades but, now, there are two reasons to reconsider them: (1) our greatly improved knowledge of the dynamics of ovarian physiology, following the application of transrectal ultrasonography, indicates that modification of the protocols may improve fertility yields and (2) increasing concerns about animal health and welfare, food safety and the environmental impact of the treatments, as evidenced by public opinion and therefore market forces. Here, we offer an overview of these issues, introduce an updated protocol and suggest ways for future improvements to the protocols.
Additional keywords: artificial insemination, breeding, eCG, progesterone, prostaglandins.
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