Effects of dietary supplementation with red yeast rice on laying performance, egg quality and serum traits of laying hens

To determine the influence of red yeast rice on production performance, egg quality and serum traits of laying hens, 288 laying hens (40-week-old) were randomly assigned into four groups with 6 replications of 12 birds each. Hens were provided with diets containing 0, 0.5, 1 and 5 g/kg red yeast rice for 8- weeks. Results showed that dietary supplementation of red yeast rice had no effect (P>0.05) on laying performance over the entire feeding period. Albumen height (quadratic, cubic, P<0.05) and Haugh units (quadratic, P<0.05) were increased with gradient addition of red yeast rice. Moreover, albumen height and Haugh units were higher (P<0.05) in 1 and 5 g/kg red yeast rice groups, with an exception of albumen height in 1 g/kg group at day 28. Yolk cholesterol content was lower (P<0.05) in 5 g/kg red yeast rice-supplemented group at day 56. There were decreased (P<0.05) contents of serum cholesterol and triglyceride, but higher (P<0.05) concentration of serum calcium in the 1 and 5 g/kg red yeast rice-treated hens compared with the control group. Serum level of very-low-density lipoprotein was also reduced (P<0.05) in 5 g/kg red yeast rice-treated hens. The results suggest that red yeast rice could lower serum and egg yolk cholesterol levels and improve the egg quality in laying hens.