Prediction breeding value and genetic parameter in Iranian Holstein bulls for milk production traits.

Data set included records of 43303 cows for first lactation. Records were collected from 2000 to 2006 in Animal Breeding Center of Iran Studied traits were yield of milk, fat, protein and percentage of fat and protein. Total number of animal was 197561 individual in pedigree. Genetic and phenotypic parameters were estimated with REML method under single trait Animal Model. Breeding values were predicted with BLUP procedure. The model for the analyses included the factors herd-year-season as fixed factor (1694 levels), animal as random effect and age at calving as co variable with minimum and maximum of 23 and 36 month. Respectively the estimated heritabilities were 0.35 (+/-0.02), 0.33 (+/-0.02), 0.31 (+/-0.017), 0.28 (+/-0.02), 0.27 (+/-0.016) for milk, fat, protein yield, percent of fat and protein. Mean of breeding values of sires were 180.2 (+/-28.2), 3.7 (+/-1.26), 2.3 (+/-1.06), -0.036 (+/-0.014) and -0.028 (+/-0.009) for milk, fat, protein yield, percent of fat and protein, respectively.