Abstract: [Objective] This study was conducted to assess the effects of dietary supplementation of soybean isoflavones and bile acids on production performance and serum physiological and biochemical indexes of green-shell laying hens. [Method] A total of 72 370-day-old green-shell laying hens were selected and randomly assigned into a control group or an experimental group, with 4 replicates in each group and 9 hens in each replicate. The control group were fed with a corn-soybean meal basal diet, while the experimental group received the same basal diet supplemented with 12.5 mg/kg soybean isoflavones and 60 mg/kg bile acids. The whole feeding experiment was consist of a 7-day preliminary trial and a 105-day formal trial. The feed intake, egg production and egg weight of each laying hen replicate during the experiment were recorded, and the average feed intake, feed to egg ratio and egg production rate were calculated. At the end of the experiment, egg samples were collected to measure egg quality indexes; blood samples were collected to prepare serum, and the serum physiological and biochemical indexes were measured. [Result] Compared with the control group, the average feed intake and egg production rate of the experimental group increased by 11.80% and 10.64%, respectively, with significant （P<0.05） differences. There were no significant （P>0.05） differences in the feed to egg ratio, egg shape index, egg weight, relative weight of eggshell, and relative weight of egg yolk between the experimental group and the control group, while there was an increasing trend in egg weight and relative weight of eggshell in the experimental group. The serum content of acetylcholinesterase （AChE） in the experimental group increased by 32.45% compared to that of the control group, with significant （P<0.05） difference. No significant （P>0.05) differences in serum contents of total protein （TP）, albumin （ALb）, glutamic pyruvic transaminase （GPT）, glutamic oxalacetic transaminase （GOT）, follicle-stimulating hormone （FSH）, and luteinizing hormone （LH） were observed between the experimental group and the control group, while increasing trends in serum contents of TP, ALb, FSH and LH as well as decreasing trends in those of GPT and GOT were observed in the experimental group. [Conclusion] Dietary supplementation of 12.5 mg/kg soybean isoflavones and 60 mg/kg bile acids for green-shell laying hens in the middle and late laying period improved the production performance and serum biochemical indexes.

Key words: green-shell laying hen, soybean isoflavone, bile acid, production performance, serum physiological and biochemical index