Embryo Transfer: storia, tecnica, applicazioni e sviluppi futuri nell'allevamento della bovina da latte

Abstract

The Embryo Transfer (ET) technique consists in the transfer of embryos from a female donor to one or more recipients. The goal of the Embryo Transfer is to perpetuate certain traits from females of high genetic value in the population. The first embryo transfer on mammals was performed by Walter Heape in 1890, who transferred rabbit embryos and the first calf born with the Embryo Transfer is attributed to EL Willet of the University of Winsconsin in 1951. The process begins with the donor superovulation: the growth and the consecutive ovulation of several follicles on the ovaries of the cow, which then will be fertilized through multiple inseminations. After 7 days, flushing will be carried out: a fluid will be inserted inside the uterus, collected, and then observed under a microscope in order to look for and evaluate embryos. These embryos can be frozen for subsequent ET, or immediately transferred into recipients which were previously synchronized. Embryo transfer can be used basically for two purposes: first of all, to promote genetic progress, and then for the “Embryo therapy”, a therapy for certain pathologies such as heat stress or repeat breeders syndrome. Studies are controversial regarding its economic sustainability, for this reason today it is thought that, given the cost which the entire transfer of 1 embryo has. Embryo Transfer is a procedure to be recommended only to super farms, which excel in all sectors of breeding and who want to improve even more by implementing their genetic development.