Submitted to: World Congress of Genetics Applied in Livestock Production
Publication Type: Proceedings
Publication Acceptance Date: 2/18/2022
Publication Date: 7/7/2022
Citation: Miles, A.M., Hutchison, J.L., Van Raden, P.M. 2022. The rising popularity of embryo transfer in U.S. dairy cattle and implications for national fertility evaluations. World Congress of Genetics Applied in Livestock Production. https://www.wageningenacademic.com/pb-assets/wagen/WCGALP2022/52_013.pdf.
Technical Abstract: This research was motivated by the exponential increase in embryo transfer (ET) use with >5 times as many ET calves born in the U.S. in 2021 compared to just 5 years earlier. A survey of the national database revealed that only 1% of ET calves correspond to ET breeding events, 2% are incorrectly reported as AI, and 97% have no associated breeding event. Herdyears reporting >10% of calves born by ET but less than half of the expected number of ET breeding events were removed, and sire conception rate recalculated with this new dataset. Subsequent analysis showed that censoring herdyears with inconsistent ET reporting has little effect, except in the case of elite young bulls popular for ET use. Improved ET reporting will be critical for providing accurate fertility evaluations, especially as the popularity of these advanced reproductive technologies continues to rise.