Comparison between trans-vaginal and recto-vaginal techniques for transferring embryos in the dromedary camels

The present study was conducted in two breeding seasons to compare the effect of two non-surgical techniques for embryo deposition intrauterine, trans-vaginal (TV) versus recto-vaginal (RV) techniques, on the pregnancy rate and early pregnancy loss (EPL) in dromedary camels. Embryos were collected from 70 donors and transferred to 210 recipients by TV (n = 256 transfers) or RV technique (n = 186 transfers). Pregnancy diagnosis was conducted on Day 10 after embryo transfer (ET) by using the progesterone-ELISA test and by trans-rectal ultrasonography at Day 60 of gestation. EPL was calculated as the recipients that were diagnosed pregnant on Day 10 post-ET and lost their pregnancy between Days 20–60 of their gestation. Using the RV technique in ET of a single embryo showed higher pregnancy rates at Day 19, especially with the embryos of folded, semi-transparent shapes, or those collected after superovulation with the recovery of >4 embryos per flush. While, the pregnancy rates at 60 days showed increases after ET with the RV technique of single, folded, transparent, and semi-transparent, medium-size embryos and/or those collected after superovulation with any number of the recovered embryos than those transferred by the TV technique. The rate of EPL was increased when the TV technique was used for ET of single, spherical, folded, semi-transparent, medium-sized embryos and those collected without or with the superovulation and recovery of >4 embryos per flush. In conclusion, using the RV technique to deposit the embryos intrauterine improves the pregnancy rate and reduces EPL compared to the TV technique.