Determine of optimum Holstein inheritance on traits performance of dairy cattle in Markazi province

In order to determine of optimum Holstein inheritance on traits performance of dairy cattle, 305-days milk production records were used 20000 Holstein cows from Markazi province. Data were collected during 1999 to 2013 by Animal Breeding Center of Iran. Generalized linear model (GLM) procedure of SAS 9.1 software was used to analyze of fixed effects (herd, month of calving, year of calving and sperm type, inheritance) and calving age as covariate on production traits. Study on Holstein cow with different ratio of inheritance was done that includes: 12, 25, 50, 62, 68, 75, and 84,87,90,92 percent. Phenotypic and genetic (co) variance components for production traits with Wombat software were estimated. Then, a selection index was constructed for combine these traits. Optimum Holstein inheritance based on this index was determined by least squares mean comparisons of the index for different Holstein inheritance and simple linear regression. Results indicated 84-92 percent Holstein inheritance was the optimum level. Optimum inheritance on milk production, amount fat and protein has positive effected and it is increased the average production.