estimation of genetic parameters and trends for some economic traits in kermani sheep

the objective of the present study was to estimate genetic parameters and genetic trends of growth traits , fleece weight and reproductive traits. data collected from 1993 to 2007 by the kermani breeding station were analyzed .traits were included birth weight (bw, n=2614), 3 months weight (3mw,n=2312), 6 months weight (6mw, n=1890), 9 months weight (9mw,n=1380) and 12 months weight (12mw,n=1052), fleece weight (fw,n=1090) , litter size at birth (lsb, n= 2115 ), litter size at weaning (lsw,n= 2014 ), total litter weight at birth (tlwb, n=2110 ) and total litter weight at weaning (tlww, n= 1930  ) and age at first lambing (afl,n=  860  ). the variances and genetic parameters were estimated by the average information restricted maximum likelihood method (ai-reml) using the software wombat, with single or multiple trait animal models and breeding values of animals were predicted with best linear unbiased prediction (blup) methodology under multi-trait animal models. genetic trends of studied traits were estimated by regressing mean of breeding values on birth year. estimated heritability in multivariate analysis for bw, 3mw,6mw,9mw,12mw, fw, lsb, lsw, tlwb, tlww and afl were 0.23, 0.57, 0.49, 0.29,0.36,  0.59 , 0.07 , 0.06 , 0.11 , 0.15 and 0.05 , respectively. estimates of correlation cofficient between all traits were positive.  estimated genetic trends of  bw, 3mw,6mw,9mw,12mw, fw, lsb, lsw, tlwb, tlww and afl were 2 , 125, 91, 81, 156, - 0.6 ,- 0.001,-0.000,0.003,0.023 and  – 1.26 , respectively.