Effect of Selection for Milk Production and General Health of the Dairy Cow

Abstract

Forty-three pairs of open heifers were purchased as foundation animals to evaluate direct response to selection for milk production and correlated responses of reproduction, digestion, respiration, skin or skeleton, and mammary disorders. One heifer of each pair was selected for high genetic potential, and the other was selected for low potential on pedigree evaluations for milk production. High pedigree cows produced more milk, but they also had 9% more digestive disorders, 5% more foot rot, 14% more skin or skeletal disorders, 11% more cases of udder edema, and 2% more lactations affected by mastitis. High pedigree cows even with the $12~46 more health costs netted $45.80 more per lactation than did low pedigree cows calving in the same year.