Nutritional characteristics and quality of eggs from laying hens fed a diet integrated with chestnut tannin extract (Castanea sativa Miller)

1. The trial was performed with 80 laying hens belonging to two Tuscan autochthonous breeds: 40 birds of the Mugellese breed (MU) and 40 of the White Leghorn breed (WL). 2. The animals were allotted to 4 groups of 20 hens each: two groups were fed on a commercial diet and worked as the control groups (MUC and WLC); the other two groups received the same diet, integrated with 2 g of chestnut tannin extract per kg of diet (MUT and WLT). 3. A sample of 70 eggs were randomly collected and analysed for cholesterol content, fatty acid profile, weight, thickness of shell and colour of yolk. 4. Physical parameters, including yolk colour, and indices of egg quality were not affected by the treatments. 5. The concentration of unsaturated fatty acids increased whereas cholesterol was significantly decreased: -17% in WLT and -9% in MUT. Dietary supplementation with chestnut tannin extract resulted in a modification of lipid composition, toward a more healthy quality of eggs.