Estimation of performance productive and reproductive traits and Comparison of various animal models to estimate genetic parameters of Yazd native fowls

This research, aimed to estimate genetic parameters to evaluate breeding strategy for some important production and reproduction traits in Yazd native fowls.For this purpose, the data collected for12 generations (2006-2015) in Yazd native fowls was used. Genetic parameters were estimated by multi-trait animal model using WOMBAT software and breeding values were predicted for all birds.The highest and lowest heritability were estimated for weight at sexual maturity (0.58±0.02) and egg weight at 1st day of laying (0.19 ± 0.01), respectively. Genetic trends of BW1, BW8, BW12, ASM, WSM, EN, EW1 and MEW were estimated, 0.39, 15.79, 25.98, -1.78, 26.65, 1.87, 0.24 and 0.69 respectively, that all traits were significant. Results of this study showed that the breeding program applied in Yazd native fowls, genetic structure has improved. Also, a series of six different animal models were fitted for all traits, and the best model for each trait was chosen based on log-likelihood ratio tests (LRT).Our results showed that maternal effects are significant in economic traits in Yazd native fowls and so, the inclusion of these effects in models, increasing the accuracy of the estimates of direct heritability .Therefore, We must in future selections program, analysis of traits under selection, with the most appropriate model to be done.