It is well known, that an adequate fertility rates has important outcomes in different species of mammals (including human). However, despite the efforts to maintain outstanding reproductive performance, the reproductive failures are still considerable. This reproductive failure is related to a failure in maternal-embryo communication. In this sense, nutritional factor is one of the most important issues involved in the reproductive efficiency. Some studies have indicated that the use of polyunsatures fatty acids (PUFAS) like omega-3 have a positve effects on human and animal health. Nowadays, the effects of diets rich in PUFAS omega-3 (PUFASn-3) on reproductive physiology have been studied assensing the follicular function, ovulation rate and oocyte quality. In addition, there is scarce information about of the mechanism and/or effectiveness of PUFASn-3 during peri-implantational period in mammals. However the outcomes obtained have been controversiel and non-conclusive, justifying the necesity to perform futher studies. Thus, the combined use of morphologic studies, hormonal assays, genomics and proteomics procedures and embryo recover/transfer technologies could be suitable methodologies to evaluate the effects of PUFASn-3 during peri-implantational period. Also, these tools could evaluate the maternal/endometrial signal (e.g: receptors expression) and gene embryonic expressions during this period. In consequence, these studies could assess the effectiveness of PUFASn-3 on maternal and/or embryo’s level. The results obtained, will contribute to enhance the productivity in animal production system. Furthermore, the use of ovine species has been a classical experimental model in human medical studies. Thus, the awarness obtained in this proposal would contribute to increase the fertility rate in women with reproductive failure during this periodreinforcing the inter/multidisciplinary dimension of this proposal (impacting in life science and agricultural fields).