©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 13 (1): 1079-1087 (2014) Genetic analysis of leece and post-weaning body weight traits in Makuie sheep S. Jafari 1,2 and A. Hashemi 1 1 Department of Animal Science, Faculty of Agriculture, Urmia University, Urmia, Iran 2 West Azerbaijan Jihad-Agriculture Organization, Makuie Sheep Breeding Station, Maku City, Iran Corresponding author: S. Jafari E-mail: Jafarishoja@yahoo.com Genet. Mol. Res. 13 (1): 1079-1087 (2014) Received January 18, 2013 Accepted July 10, 2013 Published February 20, 2014 DOI http://dx.doi.org/10.4238/2014.February.20.9 ABSTRACT. Estimation of genetic parameters is the most important component of an organized selection program. With respect to economic traits, such as wool and mutton traits, production costs can be reduced through a suitable selection program focused on genetic improvement. This study aimed to evaluate genetic parameters of leece and post-weaning growth traits in sheep. Greasy leece weight at 6, 16, 28, 40, and 52 months of age (GFW1, GFW2, GFW3, GFW4, and GFW5) represented characteristics of wool quantity. Staple length at shoulder, side, and rump (SL1, SL2, and SL3), iber diameter, and percentage of true wool (TW%) were used as characteristics of wool quality. Live body weight at 6, 9, and 12 months of age (BW6, BW9, and BW12) relected post-weaning growth characteristics. These data were collected over 23 years, from 1989 to 2012, at the Makuie Sheep Breeding and Raising Station (MSBS). Estimations were calculated using the derivative-free restricted maximum likelihood (DFREML) model. Direct heritability estimates, based on single-trait analyses, ranged from 0.10 (GFW1) to 0.80 (TW%). Additive genetic correlations among the traits ranged from highly negative (-0.46) to highly positive