Multivariate genetic analysis on body weight traits in Ghezel sheep

The present study was carried out to estimate the genetic and phenotypic parameters for growth traits in Ghezel sheep,using pedigree information and body weight records which collected from 2000 to 2009 at Ghezel Sheep Breeding Station.Traits of interest were birth weight (BW, n=2,073), weaning weight (WW, n=1,663) and six-month old weight (6MW, n=1,315).The environmental factors were studied using GLM procedure in SAS software. (Co) variance components estimated basedon multivariate animal model by REML method, using DMU-package. All traits were significantly influenced by birth year,lamb’s sex, type of birth and dam age (p<0.01). Heritability estimates for BW, WW and 6MW were 0.16±0.05, 0.24±0.06 and0.35±0.07, respectively. All genetic correlations between traits were estimated positive and ranged from 0.57 (BW-6MW) to0.97 (WW-6MW). The phenotypic correlations among all traits were also positive. The results of this study indicate thatbecause of high genetic correlation between traits, selection for each of these traits may result in improvement in other traitsas well.