Heritabilities of Some Type Appraisal Traits and Their Genetic and Phenotypic Correlations with Production

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Abstract
The heritability of 27 type traits and milk and fat production were estimated using a within-herd-year analysis of 842 daughter-dam pairs of the Holstein-Friesian breed. Heritability estimates for fat and milk production were higher (.42 and .40) than most reported previously. Most of the type traits studied had heritability estimates which were not significantly different from zero. Those traits with the highest estimates were: milking quality (.24), depth of barrel (.33), udder texture (.28), strength of udder attachment (.30), depth of udder (.22) and treatment (.40). Estimates of genetic correlations of type traits with production were inconclusive due to lack of confidence in the components of the correlation coefficients. Phenotypic correlations between 26 type traits and production were estimated. The highest correlation found was between milk and fat production. Six estimates were greater than (.15) and none of the estimates were greater than (.21). Selection indexes for breeding value for milk production were computed utilizing 7 variables having the highest heritabilities and phenotypic correlations with production. The index using all 7 variables was found to have a correlation with actual breeding value of (.58). Using milk production alone to estimate j breeding value had a correlation with breeding value of (.53).