Estimates of Genetic Parameters for Test Day and 305-day milk yield in first lactation of Mambí de Cuba Cows

Abstract Text:

Data from 14,120 test-day records from 1,826 first lactation of Mambí de Cuba(3/4 Holstein 1/4 Cebu) cows that calved between 1998 and 2013, in 136 herds, were studied.The aim of this study was to estimate the heritability (h²) and the genetic correlations between the test day records (TD) and the 305-day milk yield(MY305). Multitrait analysis on TD1 to TD10 and MY305 were performed using an animal model, which included the group of contemporaries (herd-year-month test day) as fixed effects and cow age to test day as linear and quadratic covariable; additive genetic value of the animal was the random effect. The heritability were higher for TD4 (0.23), TD5 (0.25) and TD6(0.25). Genetic correlations between TD and MY305 varied from 0.50 and 0.85.The results indicate that TD can be used as selection criterion in Mambí de Cuba cows.

Keywords:

dairy cattle

genetic parameters

test day milk yield