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Genetic parameters for linear udder traits: final score and milk and fat yields in Holstein

Data on 3,063 linear classification records from 2,593 cows, from 1997 to 1999, were used in these analyses. A multiple trait animal model for three simultaneous trait was used to obtain correlations between pairs of the linear udder traits, final score, and milk and fat yields. Averages for udder traits ranged from 3.79 for fore teat placement to 5.81 for fore udder height. The average of final score was 80 and for milk and fat yields were 7,019±1,817 kg and 236±60kg, respectively. Repeatabilities ranged from 0.46 for udder depth to 0.76 for final score and heritabilities ranged from 0.11 for udder cleft to 0.40 for final score. Genetic correlations among linear udder traits were generally high and positive. The highest genetic correlation for linear udder traits occurred between udder height and udder cleft (0.71), followed by the correlation between fore udder attachment and udder cleft (0.69). Genetic correlation that included production and udder traits showed that the highest value was 0.46 between milk yield and rear udder width. Fat yield was moderately correlated with rear udder width (0.23). Some negative relationships were found. Estimates of phenotypic correlations were generally lower in absolute values than their corresponding genetic correlations.

Dairy cattle; Holstein; udder traits; final score; milk and fat yields; genetic parameters


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