Genetic relationship between some type traits and longevity in Holstein dairy cattle of Iran

In this study، 10839 records of first parity Iranian Holstein dairy cattle (that were collected by Animal Breeding Center of Iran) were used to estimate genetic and phenotype parameters of 5 different type traits، 2 longevity traits، and their correlations. The genetic parameters were estimated by restricted maximum likelihood method with an animal model using ASREML software. Heritability estimates for type traits ranged from 0. 11 (fore udder attachment) to 0. 20 (body depth). The genetic correlation between longevity traits and type traits of body depth، loin، chest width، udder width and body size were negative and type traits of fore udder attachment، udder depth، median suspensor and udder height were positive and ranged from 0. 03 (true productive herd life with fore udder attachment) to -0. 47 (functional productive herd life with fore udder attachment). According to these results، it could be recommended to use type traits index for effective selection of animals with better longevity and fertility traits.