The Genetic Evaluation and Comparison Between Internal and Imported (Canada, America, Europe) Sperms for Milk Yield, Fat Yield and Milk Fat Percentage in Some Daily Farms of Isfahan Province

Abstract: In this study, for the purpose of genetic evaluation and comparison between internal and imported sperms (Canada, America, Europe) and assessing genetic and environmental parameters affecting some productive traits (Milk Yield, Fat Yield and Milk Fat Percentage) and some reproductive and longevity traits (age at 1st calving, herd life and productive life), lactation and pedigree data of 45 herds was collected from Animal Breeding Centre of the Agricultural Ministry in Isfahan province between 1374/01/01 and 1380/09/30. The (GLM) and (REG) procedures of SAS software was used to evaluate the way and the extent to which affecting factors influence records. Genetic parameters of Milk Yield, Fat Yield and Milk Fat percentage traits were calculated by six univariate animal models and one multivariate animal model with Derivative - Free Restricted Maximum Likelihood (DFREML) method. Direct heritabilities of Milk Yield, Fat Yield and Milk Fat Percentage traits were obtained 0.23, 0.24 and 0.393 respectively with using univariate analysis method. Also, direct heritabilities of Milk Yield, Fat Yield and Milk Fat Percentage traits were obtained 0.34, 0.276 and 0.312 respectively with using multivariate analysis method. The effect of sire origin including Iranian, Canadian, American and European sires was a significant factor for all traits in this study. American and European sires have the highest mean of breeding values in both Milk and Fat Yield traits; while the mean of breeding values of Iranian sires in both Milk and Fat Yield traits was in the lowest level. The European and Iranian sires have the highest and American sires has the least mean of breeding values in Milk Fat Percentage trait. Iranian daughters had the lowest level than the three other groups in herd life and productive life. Therefore, according to the improvement in most of the traits in this study by imported sperms the use of imported sperms is recommended with regarding to other conditions for Holstein dairy farms of Isfahan province. In addition using American sperms without considering the breeding value of the bull in Milk Fat Percentage is never recommended for those herds which confront with low Milk Fat Percentage.MSc Thesi