The development of sheep embryos when two are transferred into only one uterine horn or into each uterine horn.

In two series of experiments, two D6 morulae were surgically transferred either to each uterine horn of recipient ewes or to the same horn. When embryos were transferred to each side, the percentages of lambs born were not significantly different (68 and 62.5% respectively) whether the corpora lutea of recipient ewes were on each ovary or on the same ovary (in this case, embryos were transferred to the horn ipsilateral to the corpora lutea). When embryos were transferred to the same horn, the percentages of lambs born (71 and 92.6% respectively) were not significantly different whether the corpora lutea were on each side or on the same side. The percentages of lambs born were not significantly different whether the two morulae were transferred to each uterine horn or to the same horn.