Abstract

Linearized type records on 14,525 Holstein cows were analyzed to obtain genetic and environmental parameters. Each record consisted of scores on 15 linear type traits recorded on cows between March 1982 and October 1986. Genetic and environmental (co)variances were estimated by the algorithm of expectation-maximization of REML procedure. The model used included fixed herd-year effects, groups of unknown maternal grandsires, and linear and quadratic regressions for both age at calving and days in lactation as well as random sire and maternal grandsire effects. Heritabilities ranged from .07 for foot angle to .35 for stature. Environmental correlations were in general small: the highest was .55 between rear udder height and rear udder width. High genetic correlations were found among stature, body strength, and body depth and among the various udder traits measured. Genetic correlations among udder traits and the remaining traits were in general small. Genetic correlations among stature, body strength, and body traits with the remaining traits measured were small also, with the exception of correlations with rump width.

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