|EAGLEN, SOPHIE - National Association Of Animal Breeders|
Submitted to: Electronic Publication
Publication Type: Other
Publication Acceptance Date: 5/7/2020
Publication Date: 5/7/2020
Citation: Eaglen, S.A., Cole, J.B. 2020. What is going on with calving ease?. CDCB Connection newsletter. May 2020. Available: https://mailchi.mp/uscdcb.com/cdcb-connection-february-1376910?e=46d6707343.
Technical Abstract: Changes were made to the models used for the national calving ease and stillbirth genetic evaluations in April 2020. A bull with above-average calving ease will produce more easy births than a bull with below-average calving ease, similar with the previous trait expression. However, because genetic progress has been made over the past 20 years, the phenotypic bases used for calving ease and stillbirth are no longer consistent with the rates of dystocia and stillbirth evident in U.S. Holsteins today. Producers should not be afraid to use bulls with PTAs higher than 8% when their other PTAs are favorable. What is most important is a bull’s ranking relative to his peers.