The Use of Assisted Reproductive Technologies to Improve Genetic Selection in Cattle

Over the last 80 years, the US dairy industry saw the national milk production and individual cow milk yield increase by >80% and >400%, respectively, while the dairy cattle population and the carbon footprint of a glass of milk shrunk by >60% and 66%, respectively. Genetic improvements through artificial insemination were responsible for ~50% of these advancements. Although such dramatic statistics are not available for other assisted reproductive technologies (ARTs), they too have contributed to advancing dairy and beef industries in certain ways. Having been introduced in 2008, genomic selection has almost completely replaced phenotypic selection in US dairy cattle breeding while doubling the rate of genetic gain. Currently, it incorporates over 50 traits related to production, conformation, longevity, fertility, calving, health, and feed efficiency. With such comprehensiveness, genomic selection is expected to improve tomorrow’s cattle even further. Gene editing is used for inserting/deleting specific genetic variations followed by precision breeding to obtain animals of favorable phenotypes. While being controversial in certain aspects, gene editing is expected to receive regulatory approval within the foreseeable future. ARTs can play a crucial role in increasing production efficiency and decreasing the carbon footprint of livestock industries, especially in the tropics whose ultimate impact will be felt globally.