Direct ovarian-uterine transfer of progesterone increases embryo survival in gilts

This study employed a unilateral ovariectomy model to investigate the relevance of the local supply of progesterone (ovary) compared with the systemic supply of progesterone, in terms of embryo survival in the ipsilateral uterine horn as opposed to the contralateral uterine horn. Thirty gilts were unilaterally ovariectomised (ULO) during the luteal stage of their first oestrous cycle. Half of the ULO gilts were fed at 1.2 maintenance requirement (M), while the other half were fed at 2.4M. Across ULO gilts 0.8 more embryos survived in the ipsilateral horn compared with the contralateral horn at Day 35 of gestation (P