Type Appraisal: III. Relationships of First Lactation Production and Type Traits with Lifetime Performance

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Abstract
Phenotypic and genetic correlations were estimated between 48 type appraisal traits and first lactation milk production to determine the importance of appraisal traits in a breeding program from 5,024 records from the New York type appraisal program. Most phenotypic correlations amgng the type traits were near zero. Depth of udder was the appraisal trait having the highest correlation with first lactation milk (.27) and fat (.23). Mul- tiple correlations of all appraisal traits with first lactation milk and fat were .44 and .40. Correlations with lifetime variables were calculated from 2,068 records meet- ing time qualifications. Of the first lacta- tion variables, milk yield had the highest correlation with lifetime milk (.34), and fat yield had the highest correlation with number of lactations (.21). All appraisal traits combined were as effective as pro- duction variables in predicting number of lactations. Genetic correlations suggested that bulls that sire daughters with high pro- duction tend to sire daughters with weaker udder attachments. High genet- ic correlations between first lactation pro- duction and lifetime performance support the utility of selection on first lactation production.