With the objective to estimate the genetic parameters for milk and fat production of Holstein cows breed, the records from the Goiana Holstein Breed Producer Association using 3043 lactation of 2031 cows daughters, of 178 sires assigned to 56 herds in three different region of the Goias State, from 1990 to 1995 were analyzed. The means and standard deviations for milk production (MP) and fat production (FP) were 4458 ± 2150 kg and 149 ± 74 kg, respectively. The data were analyzed using the Derivative-free Restricted Maximum Likelihood method (DFREML) with a multitrait animal model, including the fixed effects of region, herd, year of birth, age of dam and season of calving. The predicted transmitting ability (PTA) was also estimated and its accuracy and the rank of the best sires of the Holstein breed used in the Goias State were obtained. The heritability estimates of MP and FP were .18 and .18, respectively, indicating that a small amount of the variation was due to the additive gene action. The repeatability coefficients were .21 for MP and .20 for FP showing that the first productions will not be a good indicate that the following production. The correlation coefficient between MP and FP was .98 and it indicates that the improvement of milk production will increase fat production.
genetic correlation; heritability; fat production; milk production
