Effects of replacing soybean meal with an equivalent amount of fermented feed on the production performance and egg and meat quality of laying hens during the late laying period.

This study aimed to investigate the effects of replacing soybean meal with an equivalent amount of fermented feed on the production performance of laying hens. A total of 480 healthy, 70-week-old Hy-Line Sonia laying hens were divided into three groups, with four replicates of 40 chickens in each group. The control group (NT) was fed a basal diet, while the experimental groups were fed with a diet in which soybean meal was replaced with an equivalent amount of fermented feed: 5 % replacement in treatment group 1 (TT1) and 10 % replacement in treatment group 2 (TT2). At 8 weeks after soybean meal replacement, the results showed that the abnormal egg rate in the 10 % fermented feed group was significantly reduced. Egg quality parameters, such as eggshell strength and thickness, significantly improved in both the TT1 and TT2 groups after 4 and 8 weeks of equivalent soybean meal replacement. The drip loss of breast muscle was significantly lower in the TT1 and TT2 groups compared to the NT group at both 4 and 8 weeks. In addition, there was a significant increase in the pH of thigh muscle at 0 h postmortem and a significant reduction in the fat and cholesterol contents in the muscles of laying hens in the TT1 and TT2 groups. Replacement of 10 % soybean meal with an equivalent amount of fermented feed for 8 weeks yielded a satisfactory effect.