Association of Type Traits Scored Linearly with Production and Herdlife of Holsteins

Abstract

Linear type evaluations for 18 traits on 43,428 first lactation cows were used to determine relationships of type traits with herdmate deviation milk and herdmate deviation fat. Lifetime information on 17,288 of these cows was used to evaluate type traits with herdlife. Cows were scored (1 to 50 points) for 16 traits between September 1, 1979 and January 1, 1984 by evaluators of 21st Century Genetics Cooperative Mating Appraisal program. Disposition and milkout were scored by herd owners. Cows with extreme dairy character, excellent dispositions, and moderate rump width were associated with greatest production and herdlife. Tall first lactation cows with deep udders had highest herdmate deviations for milk and milk fat, but cows with average height and udder depth had longer herdlife. Variation among herds was more important in determining herd-life than production when linear and quadratic effects for all traits were considered in models. Dairyness and udder depth had largest differences associated with herdmate deviation milk (1276 and 1167 kg), herdmate deviation fat (39 kg each), and herdlife (90 and 59 d) at ± 2 SD from the mean score. For several traits, predicted response at extreme scores was different when cubic effects were added to models. © 1989, American Dairy Science Association. All rights reserved.