부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/S0093-691X(99)00105-3 Byline: A.K. Misra (1), M. Mutha Rao (2), R. Kasiraj (1), N.S. Ranga Reddy (1), H.C. Pant (1) Keywords: buffalo; embryo transfer; pregnancy; embryonic; maternal and environmental factors Abstract: The objectives of this study were to determine the pregnancy rate and factors affecting it following nonsurgical embryo transfer in buffalo. Donor buffalo were superovulated with FSH, and embryos collected nonsurgically were evaluated for stage of development and quality. They were transferred nonsurgically to 91 recipients on Days 5 to 7 of the natural (n=52) or induced (n=39) estrus (estrus = Day 0). The overall pregnancy rate of 24/91(26.4%) was higher than in earlier reports for buffalo but was much lower than in cattle. Pregnancy rates were not affected by season (autumn vs winter), side of transfer (right vs left uterine horn), or type of estrus (spontaneous vs induced). The pregnancy rate was high 11/27(40.7%) when donors and recipients were closely synchronized, while it was compromised when recipients were in estrus at +12 h (1/7, 14.3%) and at E 12 h (5/27, 18.5%). Asynchrony beyond 12 h on either side resulted into conception failure. The pregnancy rate tended to increase with the increase in CL Size of recipients, while stage of embryonic development had no effect. The transfer of an 8-cell embryo with a 16-cell embryo led to the birth of heterosexual twins, indicating that the uterine milieu of Day 5 to 6 recipients may be tolerated by the out-of-phase 8-cell embryo, at least in the presence of a more mature embryo. Embryo quality had the greatest effect on pregnancy rate as it was higher (P Author Affiliation: (1) Sabarmati Ashram Gaushala, Lali-387 120, Kaira, India (2) Buffalo Breeding Centre, Nekarikallu-522 615, India Article History: Revised 8 October 1998; Accepted 17 February 1999