Abstract: 【Objective】 This experiment was conducted to investigate the effects of mixed addition of different levels of fermented cottonseed meal,fermented rapeseed meal and fermented palm kernel meal on growing development and meat quality traits of medium-growing Yellow-feathered chickens aged 1 to 84 days, and to provide reference for the application of mixed fermentation meal in chickens. 【Method】 A total of 480 1-day-old female ephedra chickens were randomly divided into four treatment groups according to the principle of consistent body weight,the control group (without the addition of fermented feed,CON) and the groups with low (F1),medium (F2),and high (F3) levels of fermented feed.There were 6 replicates in each group and 20 chickens in each replicate.The experiment was divided into three stages,1 to 30 days of age,31 to 59 days of age and 60 to 84 days of age.The experiment period was 84 days.The growth performance was calculated at the end of each stage.Two chickens in each replicate were selected with body weight closest to the average,then whole blood was collected and plasma was separated for biochmical indices analysis.The immune organs were dissected and weighed to calculat immune organ indexes.Carcasses were segmented to measure carcass traits,and breast muscles were dissected to evaluate meat quality traits. 【Result】 Compared with CON group,①The feed to gain ratio of chickens at 1 to 30 days and 60 to 84 days of age in F3 group were significantly increased (P＜0.05),meanwhile,European efficiency index at 1 to 30 days of age,body weight at 59 and 84 days of age,average daily feed intake at 31 to 59 days of age,average daily gain and European efficiency index at 60 to 84 days of age,and average daily gain and average daily feed intake at 1 to 84 days of age in F3 group were significantly decreased (P＜0.05).Average daily gain and European efficiency index at 31 to 59 days of age and European efficiency index at 1 to 84 days of age in F2 and F3 groups were significantly decreased (P<0.05),feed to gain ratio of chickens at 31 to 59 days of age and 1 to 84 days of age in F2 and F3 groups were significantly increased (P＜0.05).② The plasma immunoglobulin A (IgA) and interleukin-10 (IL-10) contents of chickens at 30 days of age in F3 group were significantly decreased (P＜0.05),meanwhile,the plasma triglyceride (TG) content of chickens in F1,F2 and F3 groups at 59 days of age was significantly decreased (P＜0.05).③ The thymus index of chickens at 30 days of age in F2 group was significantly increased (P＜0.05).The carcasses brightness values of abdominal at 59 days of age and shoulder at 84 days of age in F3 group were significantly increased (P＜0.05).The breast muscle rate at 59 days of age,the evisceration rate and breast muscle rate,and abdominal fat rate at 84 days of age in F2 and F3 groups were significantly increased (P＜0.05).The a^*_{24 h} of breast muscle in F2 and F3 groups was significantly decreased (P＜0.05),and the b^*_{24 h} of breast muscle in F3 group was significantly decreased (P＜0.05). 【Conclusion】 Supplementation of low levels of fermented cottonseed meal,fermented rapeseed meal and fermented palm kernel meal at the same time in the diet of medium-growing Yellow-feathered chickens aged 1 to 84 days could replace the soybean meal without affecting growth performance,carcass traits and meat quality traits.The recommended addition levels of total fermented mixed meal in the three stages were not more than 6%,8% and 10%, respectively.

Key words: fermented cottonseed meal; fermented rapeseed meal; fermented palm kernel meal; Yellow-feathered chickens; growth performance; carcass quality; meat quality