Abstract: This study was carried for investigation interaction between genotype and environment for milk and fat production traits of Holstein cattle in western provinces of Iran. In this study, used 2213 records of first lactation Holstein dairy cattle in this zone of Iran. These data get from Iranian Animal Breeding Center from 1996-2006. The edited sets include 2213 first lactation for milk and fat. Records were divided in two climates. Heritability estimates using REML method and derivative-free algorithm for milk and fat yield in semidry climate and Mediterranean climate 0.2014±0.06 and 0.2468±0.03, respectively. For estimation of Genetic correlation were used from multivariate animal model. Genetic correlation was -0.04 and 0.013 for milk yield and fat yield, respectively. EBVes correlation mean was -0.019 and 0.031 for proofs between climate for milk and fat traits, respectively. Low genetic correlation and EBVes correlation for milk and fat traits between climates Indicate to proofs have not same difference performance in both climates. In addition, Germany Sperms cause increase milk and fat yield in both climate and Iranian and American Sperms decrease milk and fat yield in both climate.
R. Yaeghoobi, H. Roshanfekr, M. Mamooee, J. Fayazi, A. Ashayerizadeh, M. Bojarpour and M.T. Beigi Nasiri, 2009. Genotype by Environmental Interactions for Milk and Fat Production Across Western Provinces of Iran. Journal of Animal and Veterinary Advances, 8: 2110-2114.