عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Data related to Yazd native fowls (obtained during 2000-2008) Yazd native fowls were made use of in the present study. The investigated traits consisted of Body Weight at 8 (BW8) and 12 weeks (BW12), Age at Sexual Maturity (ASM), Egg Number during the first three months of production period (EN) and the mean Egg Weight at 28, 30 and 32 weeks of age (EW). The genetic and phenotypic parameters were assessed through univariate as well as bivariate animal model employing ASREML software. The heritability estimates for BW8, BW12, ASM, EN and EW were 0.32± 0.01, 0.37±0.018, 0.21±0.02, 0.14±0.02 and 0.24±0.02, respectively. The respective genetic correlations of BW8 and BW12 with ASM were -0.21±0.05 and -0.28±0.05. Also, the respective genetic correlations of ASM with EN and EW were -0.95±0.017 and 0.29±0.07. The genetic trends during the 6 generations of selection were estimated using regression coefficients of breeding values on generation. Genetic trends of BW8, BW12, ASM, EN and EW were 9.55 gr, 15.35 gr, -0.03 day, 0.031 egg and 0.037 gr. The results of current study indicate that reducing the age at sexual maturity will would lead to an increase in the number of produced eggs.