Genetic and phenotypic analyses of wool weight in Lori-Bakhtiari sheep using Bayesian statistical method

Authors
A. Rashedi Dehsahraei
J. Fayazi
M.T. BeigiNassiri
M. Vatankhah
10.22077/jlr.2014.256
Abstract
For this study, a total of 6,326 records of wool weight obtained from 273 rams and 1,927 ewes of Lori-Bakhtiari sheep were used. The data were collected in Shahrekord sheep breeding station (Sholi) during 1990-2011. SAS statistical software was utilised to determine the effect of environmental factors, and MTGSAM software via Gibbs sampling was applied to estimate genetic parameters. Environmental factors such as birth year, sex, type of birth, and age of mother had significant effect on the trait. The interaction between age of mother and sex of lamb, and interaction between type of birth and sex of lamb were significant. Animal’s age at shearing and birth weight were taken into account as covariates in the models. Using the best model, direct and maternal heritabilities for wool weight were 0.31±0.02 and 0.06±0.01, respectively. Direct and maternal genetic trends were 3.23±0.24 and 0.3±0.04 gr per year,respectively and statistically significant. Phenotypic and environmental trends were found to be 0.003 and -0.001, respectively but non-significant. Genetic progress was considerable at different years which could be due to breeding programs targeted at these stations. 
Keywords
Lori-Bakhtiari sheep
Wool weight
Genetic trend
Gibbs sampling