Monitoring of health status, performance and transcript abundance of some genes in dairy heifers produced by embryo transfer or artificial insemination

Abstract

The use of multiple ovulation and embryo transfer (MOET) technology in the dairy cattle industry has increased dramatically in recent decades for the production of offspring from genetically superior cows. Yet, its long-term ramifications on adult performance have not been adequately clarified. Therefore, this study targeted comparing dairy heifers born after the transfer of in vivo-produced embryos (MOET-heifers, n = 400) and those born after artificial insemination (AI-heifers, n = 340). The performance of MOET-heifers and AI-heifers was compared from birth till completion of the first lactation regarding health, fertility and some lactational performance parameters. The transcript abundance of several genes was also assessed in peripheral blood leukocytes (PBWC). Results showed greater pre-weaning mortalities, greater likelihood of being culled as a nulliparous heifer and younger age at first insemination in AI-heifers (p