PREGNANCY RATE OF CATTLE EMBRYO RECIPIENT WITH DIFFERENT DEGREES OF DIFFICULTY ON EMBRYO TRANSFER PROCEEDING

Abstract

To evaluate the influence of the difficulty of cervix transposition, uterine tonus and place of embryo trnasfer on pregnancy rate of cattle embryos recipient, the superovulation and synchronization of donor and recipients were carried out. The difficulty of cervix transposition influenced the pregnancy rate. The pregnancy rate was 50.50% (420/830) for group CERV-E (cervix of easy transposition) and 43.02% (114/265) for group CERV-D (with some degree of difficulty of transposition). The uterine tonus did not affect the pregnancy rate. The groups TON-R (relaxed uterus), TON-M (medium relaxed uterus) and TON-C (contracted uterus) achieved rates of 50.08% (313/625), 45.69% (106/232) and 47.11% (106/225), respectively. Data also showed that the embryo transfer place affected the recipient pregnancy rate. Group DEP-F (embryo transfer at the final third) achieved pregnancy rate of 51.39% (314/611), higher than group DEP-I (at the initial third), which was 39.46% (58/147), while group DEP-M (at the middle third) achieved pregnancy rate of 48.22% (163/338), similar to DEP-I and DEP-F groups. The results suggest that, in embryo transfer programs, the technician should take into special account the difficulty of cervix transposition and the embryo transfer place.

KEYWORDS: Bos indicus; embryo transfer; pregnancy rate.