Lowered Blood Carotenoid Levels in Chickens Infected with Coccidia

Abstract

Chickens infected with any one of the six major species of chicken coccidia had lower levels of blood carotenoids (plasma pigmentation) than did uninoculated control birds. The species were Eimeria acervulina, E. mivati, E. maxima, E. necatrix, E. brunetti, or E. tenella. Carotenoids decreased as early as 4 days postinoculation (PI) (E. acervulina), but returned to a normal level by 14 days PI (E. mivati, E. acervulina, and E. tenella). The maximum decrease occurred at 7 or 8 days PI in all species and was 49.8% with E. tenella and 62.4%-74.0% with the five intestinal species. Additional studies with E. tenella, E. acervulina, and E. brunetti indicated that the magnitude of the decrease was related to the number of oocysts given within any one species. Increasing oocyst number also resulted in a more rapid reduction of longer duration in carotenoid levels.