Document Type : Research Paper

Author

• E. Mirza Mohammadi

Abstract

In this research to estimate of genetic parameters and inbreeding effect for birth weight (BW) and lamb survival(LS) in Balouchi lambs, we used of 12040 records, which collected by  the center of Sheep Breeding Station of (Abbasabad), during the period 1989 to 2009. Genetic parameters estimated with use of 16 difference model, inclusive animal, and threshold and sire model with use of REML method. The most appropriate model was determinate based on log likelihood method. The suitable model for BW included direct additive genetic, maternal additive genetic, maternal permanent environmental and common litter effects. Also, suitable model for LS were included direct additive genetic and common litter effects. Direct heritability for BW was 0.05±0.01, and direct heritability for LS with animal, threshold model and sire model was 0.07±0.01, 0.16±0.08 and 0.31±0.1 respectively. It also genetic, environment and phenotypeic correlation between BW and LS was 0.12±0.01, 0.12±0.2 and 0.10±0.01 respectively, (p<0.05). The mean of inbreeding coefficients in population and inbreed animals were 0.60 and 31.2%, respectively. The estimates of inbreeding depression were -2.62 gr for BW and -0.08 percent for LS, respectively (p<0.05)..

Keywords

• Animal model
• common litter
• Genetic correlation
• threshold model
• sire model