Estimation of the Genetic Parameters for Test-Day Milk Yield in Holstein Cattle

Abstract

The objective of this study was to determine the genetic parameters represented by heritability for test-day milk yield, the genetic correlations between test-days milk yield and the breeding value for Holstein cows. The model used was random regression test-day animal model. The data set consists of 216 test day records from 30 cows. The average number of test day per lactation was seven. The heritability estimates for test-day milk yield ranged from 0.43 at 250th day in milk, to 0.60 at 10th day in milk. Genetic correlations between individual test days milk yield were high and positive.

Keywords

• breeding value
• random regression test-day model
• test day milk yield