Phenotypic and genetic analyses of reproductive traits of Holstein cattle in the provinces of Yazd, Zanjan and Tabriz

To compare the genetic parameters, genetic and environmental correlations between reproductive traits related to fertility than 85324 records (interval calving, days open and fertility rates 20 herds(34680 cows) in five lactation and climate, cold (Tabriz province) , moderate (Zanjanprovince) and tropical (Yazd Province) during the years 1985 to 2010 were of. To find out the factors affecting the characteristics and comparisons of mean GLM procedure and Duncan test using of SAS software was used. Components to estimate (co) variance components and genetic parameters in animal models by restricted maximum likelihood method without the derivative as a trait and multi-trait analysis and reliability modeling methods in WOMBAT32saftware used. Herd effects in the model - in - season of calving and parity as fixed effects and age of the cow's stomach at the time of birth was considered as a covariate. Heritability of reproductive traits ranging from 0.02 to 0.075, respectively.Difference significant genetic correlation was observed between. Traitpregnancy rates among different areas of significant differences (P <0.05).Addition, results showed a significant difference between the different regions traits of calves from birth, and there are open days (P <0.01). Trait rate there are significant differences between different areas of pregnancy (P <0.05).