Genetic Relationships Between Milk Production and Type in Holsteins

Abstract

Official scorecard and descriptive type data recorded by the Holstein-Friesian Association of America from 1967 through 1971 and sire summaries of production by the United States Department of Agriculture from 1968 to 1972 were used to determine genetic relationships between type and production. Daughter averages for type and predicted differences for production were from 1,095 sires that had a minimum of 20 classified daughters in at least 10 herds and a subset of 455 sires with a minimum of 100 daughters in at least 10 herds. Genetic correlations between predicted difference of milk and final score were –.14 for the 1,095 bulls and –.23 for the 455 bulls. Correlations between predicted difference of milk and scorecard traits ranged from –.14 to –.16 in the 1,095 bulls and –.22 to –.24 for the 455 bulls except for dairy character .38 and .41. Corresponding correlations for descriptive traits ranged from –.02 to –.22 for the 1,095 bulls and –.08 to –.36 in the 455 bulls. Correlations between milk and percent incomplete (proportion of daughters failing to complete the first record), predicted difference of fat, and percent milk fat were –.43, .73, and –.42 for the larger sample and –.54, .70 and –.40 for the other. Genetic relationships between production and type were consistently negative (but small). © 1974, American Dairy Science Association. All rights reserved.