University of Guilan Animal Production Research 2252-0872 10 3 2021 11 22 Estimation of inbreeding effects and its impact on some production and reproduction traits in West Azerbaijan native fowls Estimation of inbreeding effects and its impact on some production and reproduction traits in West Azerbaijan native fowls 21 32 5236 10.22124/ar.2021.18117.1573 FA Sh. Ghorbani Assistant Professor, Animal Science Research Institute of Iran, Agriculture Research, Education, and Extension Organization (AREEO), Karaj, Iran S. Zakizadeh Associate professor, Animal Science Research Institute of Iran, Agriculture Research, Education, and Extension Organization (AREEO), Karaj, Iran Journal Article 2020 11 07 The present study aimed to estimate the inbreeding coefficient and its impact on the economically important traits in West Azerbaijan native fowls. In this research, 61563 records collected from 1994 to 2018 (21 generations) from the breeding station of West Azerbaijan native fowls was used. The inbreeding coefficient of birds and the impacts of individual and maternal inbreeding on traits were estimated. Pedigree analysis showed that 54981 (89.31 %) of all chickens were inbred in the breeding station of West Azerbaijan native fowls and the averages of individual and maternal inbreeding coefficients were estimated to be 0.06 and 0.05, respectively. Inbreeding depression for body weight at hatch, at eight weeks and 12 weeks of age, age and weight at sexual maturity, egg number (the first 12 weeks of production), an average of egg production in 28^th, 30^th, and 32^nd weeks of production, and weight at the first egg-laying due to one percent increase in individual inbreeding was as -0.04, -1.52, -2.49, 0.12, -1.22, -0.01, <br />-0.01 and -0.02, respectively. The results showed despite close population in Azerbaijan native chicken station, the inbreeding rate was low because of implementing appropriate mating designs. Although, the absence of inbred birds is almost impossible in the closed population, it is possible to have a suitable mating design for reducing the probable undesirable effects of inbreeding. The present study aimed to estimate the inbreeding coefficient and its impact on the economically important traits in West Azerbaijan native fowls. In this research, 61563 records collected from 1994 to 2018 (21 generations) from the breeding station of West Azerbaijan native fowls was used. The inbreeding coefficient of birds and the impacts of individual and maternal inbreeding on traits were estimated. Pedigree analysis showed that 54981 (89.31 %) of all chickens were inbred in the breeding station of West Azerbaijan native fowls and the averages of individual and maternal inbreeding coefficients were estimated to be 0.06 and 0.05, respectively. Inbreeding depression for body weight at hatch, at eight weeks and 12 weeks of age, age and weight at sexual maturity, egg number (the first 12 weeks of production), an average of egg production in 28^th, 30^th, and 32^nd weeks of production, and weight at the first egg-laying due to one percent increase in individual inbreeding was as -0.04, -1.52, -2.49, 0.12, -1.22, -0.01, <br />-0.01 and -0.02, respectively. The results showed despite close population in Azerbaijan native chicken station, the inbreeding rate was low because of implementing appropriate mating designs. Although, the absence of inbred birds is almost impossible in the closed population, it is possible to have a suitable mating design for reducing the probable undesirable effects of inbreeding. https://ar.guilan.ac.ir/article_5236_3d52d34af7641aefe6ba2ec2cfd2ce8c.pdf