ABSTRACT. The objective of the present study was to estimate the heritability and to assess the existence of maternal effects for economic traits in Iranian native fowl. Variance components were estimated for body weight at hatch (BW0), 8 (BW8) and 12 (BW12) weeks of age, age (ASM) and weight (WSM) at sexual maturity, egg number (EN) and average egg weight at 12th, 28th, 30 and 32 nd weeks (EW) using restricted maximum likelihood method and six animal models. The best model was determined using Akaike's information criterion for each trait. For ASM, the basic model consisting of direct genetic effects was superior. For WSM and EN, a model consisting of maternal permanent environmental effects in addition to direct genetic effects was the best. For EW, the model with direct and maternal genetic effects assuming no covariance between them was the best. For BW0, BW8 and BW12, the model including maternal genetic and permanent environmental effects in addition to direct genetic effects was most appropriate. The estimates of direct heritability ranged from 0.05 (BW12) to 0.35 (WSM). Direct genetic variance and heritability were overestimated if maternal effects were ignored in the statistical model for all traits except ASM. The results indicated that The evaluation of direct and maternal genetic and phenotypic trends based on the best model for each trait was carried out. Maternal genetic trends for BW0, BW8, BW12 and EW were significantly positive. Present results indicated favorable effects of the performed breeding program for all traits except BW0 during generations.

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