Local influence of the corpus luteum on the ipsilateral oviduct and early embryo development in the ewe

The objective of this study was to evaluate the local effect of the corpus luteum (CL) on ipsilateral oviduct-uterus functionality and early embryo development in ewes. A total of 499 embryos were transferred on Day 1 after in vitro fertilization into the ipsilateral (n = 250) and contralateral oviducts (n = 249) of 13 ewes on Day 1 after ovulation (18-20 embryos per oviduct). On Day 6, their reproductive tracts were collected and their uterine horns were flushed for embryo recovery. More recovered embryos, a higher proportion of blastocysts, and more viable embryos were collected when the embryos were transferred into the ipsilateral oviducts (P