• acidi grassi
• colesterolo
• tannini di castagno
• tuorlo d'uovo

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).
The animals were allotted to 4 groups of 20 hens each: 2 groups were fed a commercial diet and worked as the control groups (MUC and WLC); the other 2 groups received the same diet, integrated with 2 g of chestnut tannin extract per kg of diet (MUT and WLT).
70 eggs were randomly collected and analysed for cholesterol content, fatty acid profile, weight, thickness of shell and colour of yolk.
Physical parameters, including yolk color, and indices of egg quality were not affected by the treatments.
The concentration of unsaturated fatty acids increased whereas cholesterol resulted significantly depressed: -17% in WLT and -9% in MUT. Dietary integration with chestnut tannin extract resulted in a modification of lipid composition, toward a healthful quality of eggs.