Bioavailability comparison of free and esterified lutein for layer hens

Abstract

Lutein supplements are often used to pigment and enrich layer chicken eggs. This experiment was conduced to compare the bioavailability of free and esterified lutein, by depletion method. Forty chickens were randomly divided into two groups. After 2 weeks of washout period, when all birds were fed the same low lutein basal diet, the two groups were fed for another 2 weeks with diets supplemented with free lutein or esterified lutein. Two experimental diets were supplemented with the same amount of 15 mg lutein/kg. On day 0 (baseline) and days 3, 7, and 14, birds fasting morning plasma samples were collected and stored for lutein analysis by high performance liquid chromatography method (HPLC). Results showed that: 1) Plasma lutein concentration increased dramatically after feeding free or esterified lutein; 2) Plasma lutein level in birds fed the diet supplemented with free lutein significantly differed from those fed esterified lutein on day 3. 3) There were no significant differences in plasma lutein levels between free lutein and esterified lutein on days 7 and 14. In conclusion, the lutein bioavailability from free lutein or esterified lutein supplements was comparable.