Abstract: The objective was to select green and safe feed additive for improving egg quality, 756 Roman layers with 50-week laying age were divided into 7 groups. The treatment group 1 was the control group, fed with the basal diet; the treat-ment group 2 was fed with 0.04% Chinese herbal medicine in the basal diet; the treatment group 3 was fed with 0.04% Chinese herbal medicine and 0.01% enzyme preparation in the basal diet; the treatment group 4 was fed with 0.04% Chinese herbal medicine, 0.01% enzyme preparation and 0.1% anti-bacterial peptide in the basal diet; the treatment group 5 was fed with 2‰ probiotics in the basal diet; the treatment group 6 was fed with 2‰ probiotics and 0.01% enzyme preparation in the basal diet; the treatment group 7 was fed with 2‰ probiotics and 0.01% enzyme preparation, 0.1% anti-bacterial peptide in the basal diet. The results showed that compared with the control group, the treatment group 4 was the best, and laying rate increased significantly (P<0.05), feed-egg ratio decreased significantly (P<0.05), the Haugh unit increased significantly (P<0.01). Furthermore, the treatment group 4 of the content of total amino acids was the highest, but cholesterol was the lowest. Based on the study, a combination of Chinese herbal medicine, enzyme preparation and anti-bacterial peptide was recommended for improving of egg quality.

Key words: double-low rapeseed meal; Chinese herbal medicine; enzyme preparation; probiotics; antibacterial peptide