Abstract: This study aimed to investigate the effects of fermented feed on the production performance and egg quality of Hy-Line Brown laying hens. The experimental fermented feed was prepared using corn and soybean meal as fermentation substrates and using lactic acid bacteria and Saccharomyces cerevisiae as fermentation starter. A total of 600 Hy-Line Brown laying hens of 336 days old were randomly divided into 4 groups with 150 hens for each group. The basal diet of experimental groupsⅠ~Ⅲ was supplemented with 3%, 5% and 8% fermented feed, respectively, and the control group received no dietary supplementation of fermented feed. The feeding experiment period lasted for 4 weeks, and the indices associated with production performance and egg quality were determined and statistically compared. The results showed that the addition of different proportions of fermented feed to the basal diet could improve the production performance and egg quality of the laying hens to a certain extent. At the second week of feeding the fermented feed, the egg production in the experimental groupⅡwas significantly （P<0.05） increased compared to the control group; at the third week of feeding the fermented feed, the egg production and total egg weight in the experimental groupⅡwas significantly （P<0.05） increased compared to the control group; after 4 weeks of feeding the fermented feed, the egg production, total egg weight, and egg production rate in the experimental groupⅡwas significantly （P<0.05） increased compared to the control group, and the feed/egg ratio was significantly （P<0.05） reduced; the eggshell strength in the experimental groupⅡwas significantly （P<0.05） higher than the control group; the Haugh unit in the experimental groupsⅡ and Ⅲ was significantly （P<0.05） higher than the control group. In conclusion, dietary supplementation of different proportions of fermented feed in the basal diet can improve the production performance and egg quality of Hy-Line Brown laying hens, and the adding level of 5% is recommended.

Key words: fermented feed, lactic acid bacteria, Saccharomyces cerevisiae, Hy-Line Brown laying hens, production performance, egg quality