Summary and Implications
A joint analysis of days open and calving success was implemented to further enhance the identification of cows with greater genetic merit for reproductive performance. Calving success is a categorical trait with similar genetic variation as days open and is analyzed jointly with days open to make effective use of the positive genetic correlation between these two traits. The joint analysis can identify cows with greater genetic merit for conception at an earlier stage of lactation and greater success at maintenance of pregnancy. The joint analysis also enhances the reliability of detecting true genetic differences between cows for fertility because it makes more effective use of all data.
Iowa State University
Gutierrez, Gustavo A.; Berger, P. Jeff; and Healey, Mary H.
"Joint Genetic Analysis of Conception and Maintenance of
Pregnancy in Dairy Cattle Using a Linear-Threshold Model ,"
Animal Industry Report:
AS 654, ASL R2303.
Available at: http://lib.dr.iastate.edu/ans_air/vol654/iss1/52