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Vertebrate reproductive science and technology
RESEARCH ARTICLE

Role of melatonin on embryo viability in sheep

José-Alfonso Abecia A C , Fernando Forcada A , María-Isabel Vázquez B , Teresa Muiño-Blanco A , José A. Cebrián-Pérez A , Rosaura Pérez-Pe A and Adriana Casao A
+ Author Affiliations
- Author Affiliations

A Instituto Universitario de Investigación en Ciencias Ambientales de Aragón (IUCA), Universidad de Zaragoza, Facultad de Veterinaria, Miguel Servet, 177, 50013 Zaragoza, Spain.

B Departamento de Reproducción Animal, Facultad de Agronomía y Veterinaria, Universidad Nacional de Río Cuarto, Ruta Nacional 36, Km 601, 5800 Río Cuarto, Córdoba, Argentina.

C Corresponding author. Email: alf@unizar.es

Reproduction, Fertility and Development 31(1) 82-92 https://doi.org/10.1071/RD18308
Published online: 3 December 2018

Abstract

Melatonin is a natural hormone synthesised in the pineal gland, the activity of which is regulated by day–night perception and dictates seasonal rhythms in reproduction in ovine species. Exogenous melatonin, administered via subcutaneous implants, is used to prolong the breeding season of ewes and can increase the proportion of pregnant ewes (fertility rate) and litter size. The increased proportion of ewes that become pregnant and the number of lambs born per lambing among melatonin-treated sheep may be caused by increased embryo survival, through enhanced luteal function, reduced antiluteolytic mechanisms, or improved embryo quality. This review focuses on the effects of melatonin on embryo viability and summarises the processes by which this hormone affects the ovary, follicle, oocyte, corpus luteum and embryo. Moreover, the effects of melatonin on the mechanisms of in vivo maternal recognition of pregnancy in sheep and the protective action that it appears to have on the in vitro procedures that are used to obtain healthy embryos are reviewed.

Additional keywords: follicle, ovary, oxidative stress, uterus.


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