ENVIRONMENT AND HEALTH Effect of Dietary Lipid on Lutein Metabolism During Aflatoxicosis in Young Broiler Chickens1-2

ABSTRACT The effect of concentration of dietary fat on pigmentation of broiler chickens was investigated in diets containing: 1) 0 or 1.4 ug of aflatoxin and 35 |ig of lutein/kcal of diet; and 2) different levels of dietary fat (0, 2, 4, 6, 8, or 10 % cottonseed oil). Serum lutein and its metabolite, 3'-oxolutein, increased with increasing dietary fat until it reached a plateau at 6 % fat. Aflatoxin significantly (P<.05) lowered serum lutein and 3'-oxolutein at all levels of fat. Dietary fat and aflatoxin interacted significantly (P<05), with the effect of aflatoxin being greater at the low levels of fat than at the high fat levels. In the toe webs of the birds, the concentrations of lutein and its metabolites, lutein monoester, lutein diester, and 3'-oxolutein responded similarly to aflatoxin and to dietary fat, except that increasing the amount of dietary fat did not spare the effect of aflatoxin on 3'-oxolutein. The effect of chain length and the saturation of fatty acids on the absorption of lutein during aflatoxicosis was investigated in a factorial design for aflatoxin (0 and 4 u.g/g of diet) and seven fatty acids at 5 % of the diet. In control birds, lutein absorption was promoted by lauric = oleic> capric = linoleic> myristic> palmitic = stearic acids. Aflatoxin significantly (P<.05) depressed the absorption of lutein regardless of the fatty acid present There was a significant (P<.05) interaction with short-chain, saturated fatty acids (capric and lauric), giving a partial sparing effect against the depression of lutein absorption caused by aflatoxin. These results can be explained in large part by assuming that aflatoxin decreases the ability of chickens to form micelles during lipid digestion in the amount and character needed for optimal absorption of lutein from intestinal contents