RÉSUMÉ
Productive and reproductive performances in terms of body weight, age at first egg, egg production, egg weight, fertility, hatchability and mortality of Vanaraja, Rainbow Rooster, Kamruapa and Desi chicken of Assam were studied under traditional backyard system of rearing. The Vanaraja, Rainbow Rooster and Kamruapa birds were given to rear under the frontline demonstration programmes of the Krishi Vigyan Kendra, Dhemaji to the women farmers of the district during 2020-21. The data on bird weights at different ages, egg weights, fertility, hatchability as well as mortality were collected and recorded and compared among the varieties. The data recorded from the study were analyzed as per standard statistical methods. The overall mean body weights were significantly (P < 0.05) higher in all the improved varieties than Desi chicken at different ages. There is also significant (P < 0.05) difference of age at first egg among Vanaraja (182.05±5.52 days), Rainbow Rooster (175.08±6.13 days), Kamruapa (163.06±5.52 days) and Desi chicken (203.31±3.31 days). The mean egg production values up to 32, 40, 52 and 72 weeks of age in the demonstrated varieties were significantly (P < 0.05) higher than the corresponding values of Desi birds. The mean egg weights of Vanaraja, Rainbow Rooster, Kamruapa at 32, 40 and 52 weeks of age were also significantly (P < 0.05) higher than Desi birds. However, no significant difference was observed in mortality rates among the four groups at different ages. There was also no significant (P < 0.05) difference in fertility and hatchability percent among the four genetic groups. It is concluded that Vanaraja, Rainbow Rooster and Kamruapa birds are adapted well under traditional backyard rearing system in agro-climatic conditions of Dhemaji district of Assam with adequate economic advantages over the Indigenous birds.