The effects of an advanced uterine environment on embryonic survival in the mare

摘要: Summary Reasons for performing the study: During embryo transfer (ET) equine can tolerate a wide degree of negative asynchrony but positive >2 days usually results in embryonic death. There is still confusion over whether this due to inability induce luteostasis or an inappropriate uterine environment. Objectives: To assess survival and development advanced environment. Hypothesis: Embryo–uterine asynchrony, not embryo's luteostasis, responsible death recipient mares with chronologically uterus. Methods: Experiment 1: Thirteen Day 7 embryos were transferred uteri luteal prolongation, occasioned by manual crushing their own conceptus, such that donor–recipient was between +13 +49 days. 2: carrying conceptus at Days 18 (n = 2), 15 14 4), 12 4) 11 gestation. In addition, 8 4 pregnant on gestation. Results: No pregnancies resulted following recipients prolonged dioestrus asynchronies However, use early as 5/20 (25%) twin pregnancies, which came from recipient. All showed retarded growth, occurring 4/5 (80%). Conclusions and potential relevance: The emphasise importance appropriate environment growth survive uterus even when achieved. It possible normal, non-ET pregnancy, embryo–uterine may account some cases