Estimation of autosomal and sex-linked heritabilities for some economic traits in Kermani sheep

Separation of autosomal and sex-linked direct additive genetic effects has a high importance in breeding programs and very little is known about them. This study was conducted to determine the autosomal and sex-linked additive genetic effects on some economic traits in Kermani sheep. Traits were included birth weight (BW), 3 month weight (W3), 6 month weight (W6), 9 month weight (W9) ,12 month weight (W12), daily gain before weaning (ADGa), daily gain from weaning to 6 month weight (ADGb), daily gain from 6 month weight to 12 month weight (ADGc), kleiber ratio before 3 month weight (KRa), kleiber ratio for 6 month weight (KRb), kleiber ratio for 12 month weight (KRc) and fleece weight(FW) that data collected from 1993 to 2012 by the Kermani Breeding Station. Variance components were estimated by Average Information algorithm of Restricted Maximum Likelihood using Wombat software. Direct autosomal heritability estimates for BW, W3, W6, W9, W12, ADGa, ADGb, ADGc, KRa, KRb, KRc and FW were 0.05± 0.04, 0.26± 0.02, 0.33± 0.02, 0.05± 0.03, 0.23± 0.05, 0.15± 0.02, 0.27± 0.03, 0.18± 0.02, 0.08± 0.03, 0.24± 0.02, 0.04± 0.03 and 0.15± 0.07 respectively. Sex-linked direct heritability estimates for these traits were between 0.01 to 0.03. The findings showed that sex-linked genes possibly have negligible and close to zero additive genetic effects on body weights and yearly fleece weight.