Effects of dietary phytosterol concentration on performance, egg quality and cholesterol content in laying hens

Phytosterols are widely used in human and animal foods because of their cholesterol-lowering properties, but their effectiveness as a feed additive for laying hens is still controversial. The present study was conducted to evaluate whether a high concentration of phytosterols affects the health and performance of laying hens. Three hundred and sixty 21-week-old laying hens were randomly assigned to 5 groups with 6 replicates of 12 birds each and were supplemented with 0, 20, 80, 400 and 800 mg/kg of phytosterols starting at the 24-week-old stage for 12 weeks. Laying performance and clinical observations were measured and recorded throughout the study. Egg quality and cholesterol in serum, liver and yolk were determined. Shell thickness and egg composition (shell, yolk and albumen percentage and yolk cholesterol content) were significantly affected by concentration with phytosterols (P < 0.05). No statistically significant changes were observed for laying performance, other egg quality parameters or liver and serum cholesterol content. These findings suggest that supplementing with phytosterol at doses up to 800 mg/kg would have no adverse effects on laying performance, egg quality, and cholesterol content, with the exception of yolk cholesterol content.