Received: 18-04-2017 / Accepted: 26-07-2017
From December, 2015 to December, 2016, for the first time 1,117 frozen gender-separated embryos were imported to Vietnam. In the cooperation program between TH milk group and Sexing Technology Companythe embryos weretransferred to aherd of heifers from 13 - 16 months old in TH’s Farm in Nghia Dan, Nghe An. Total 2143 heifers were synchronized for estrus by PGF2α. 1,661/2,143 = 77.5%%, in which 1,035 /1,637= 63.2% heifers were qualifiedfor receivingembryo. 1,051 gender separated embryos were transferred to1,051 heifers (in which 1,035 estrous heifers by injection PGF2α and 16 heifers naturally estrous). After 35 days of embryo transplantation(42 days age of embryo) the pregnancy was checked by Ultrasound or by rectal palpation. 488/1,051 = 46.4% heifers became pregnant, the pregnancy rate depending onseason, farmcondition, quality and location of corpus luteum on heifer receivingembryos, and skillsof technicians. The highest pregnancy rate was52.6%and thelowest was 40.9%. During the pregnancy, 10% of pregnant heifers showed abortionand5% with stillborn. The pregnant heifers gave birth to203 normal calves, including195 female calves (96.05%)and 8 male calves (3.95%).