Genetic analysis of some type, production, reproduction and longevity traits in Isfahan province Holsteins

In this study, records of 7 herd first lactation dairy cows were used. Data was collected from 2003 to 2013 by Aria Delta gene and during this study were evaluated. Traits in this study included production (milk, fat, protein yield), type (body depth, angularity, support udder, , fore udder attachment, udder depth) and reproductive (open days and age at first calving) and length of productive life traits. Data analysis was performed by restricted maximum likelihood procedure using wombat software. Heritability estimates of milk, fat, protein yield, , 0.28, 0.49, 0.42 and heritability of age at first calving and open days 0.69, 0.07 and heritability of body depth, angularity, support udder, fore udder attachment, udder depth, respectively, 0.27, 0.25, 0.12, 0.05 and 0.36 respectively and heritability was estimated length of productive life 0.2. . Genetic correlations were between milk and fat yield and genetic correlation between milk and protein yield 0.12 and 0.05 respectively. Genetic correlations between of open days and age at first calving traits 0.21 respectively. Genetic correlations among type traits in the range of -0.51 to 0.72 and phenotypic correlation between type traits in the range of -0.19 to 0.22, respectively. The greatest positive genetic correlation was estimated between body depth and angularity 0.7 and the highest negative genetic correlation between the body depth and udder depth -0.51. The estimated genetic correlations between production, reproductive and length of productive life traits ranged from -0.51 (length of productive life traits and protein yeild) to 0.63 (age at first calving and fat yield). Considering negative genetic correlation between production and reproduction traits, planning of selection programs in dairy cows based on a combination of production and reproduction traits is recommendable. Genetic correlations variable among type traits and longevity in the range 0.01 to 0.39.