Investigation the effect of cytoplasmic inheritance on growth traits of Arabi sheep using Bayesian method.

In order to evaluate cytoplasmic inheritance of growth traits (including birth weight, 3, 6, 9 and 12 month weight), the total number of 19717 Arabic sheep records which was collected by Agricultural Organization of Khuzestan province was used during1989 to 2010. Following the cytoplasmic lines from progeny to the parents, cytoplasmic primary sources were identified. Environmental factors affecting these traits were analyzed by SAS statistical software. Genetic parameters were estimated using Bayesian statistical method and MTGSAM software. Significant effect (P <0.01) on traits including lambs sex, birth type, maternal age and birth year were found. Based on the lowest acacia criteria in Bayesian statistical method, models 5, 5, 3, 4, 3 for birth weight, 3, 6, 9 and 12 months were the best models respectively. The cytoplasmic inheritance for birth weight, 3 months of age was 0.02, 0.03, and for the weights at 6, 9 and 12 months age, there was no cytoplasmic inheritance. However, the observed cytoplasmic variance for birth weight and 3 months old weight in Arab sheep were 0.004, 0.410, respectively, while no cytoplasmic variance for 6 to 12 months old was observed. Generally, although for the weight trait the share of cytoplasmic inheritance was low, but considering maternal effects and cytoplasmic heritages would result in a more accurate estimation of the genetic parameters of the growth traits of all ages.