Changes in carotenoid and vitamin A levels in young turkeys infected with Eimeria meleagrimitis or E. adenoeides.

Changes in levels of plasma xanthophyll, plasma retinol, liver retinol, and liver retinylpalmitate in poults infected with Eimeria meleagrimitis or E. adenoeides were measured by high-performance liquid chromatography. Infection with either species significantly reduced total plasma carotenoids; the reduction was due largely to a decrease in xanthophyll to approximately 50% of control levels on the day of maximum effect. In addition, E. meleagrimitis infection decreased plasma retinol levels from 1.84 microgram/ml plasma (controls) to 1.00 microgram/ml plasma on day 6 postinoculation. Concomitantly, liver retinol levels fell from 0.23 microgram/mg protein (controls) to 0.15 microgram/mg protein, and liver retinylpalmitate levels fell from 0.74 microgram/mg protein (controls) to 0.44 microgram/mg protein. In contrast, Eimeria adenoeides infection caused little change in either plasma or liver retinol levels.