Description:
<jats:p>The antioxidant potential of dietary carotenoids is widely debated for birds, with some studies supporting a protective role whereas others report either no effect or even a pro‐oxidant effect. However, the majority of previous research on this topic has not analyzed the oxidative status of a series of tissues in animals and has not considered a range of carotenoid dosages. Therefore, we investigated the effects of three levels of dietary carotenoid supplementation on plasma, liver, adipose, heart, and breast muscle oxidative damage in two congeneric species of ducks. After a 6‐week depletion period, captive adult northern pintail (<jats:italic>Anas acuta</jats:italic>) and mallard (<jats:italic>A. platyrhynchos</jats:italic>) ducks of both sexes were fed either a carotenoid‐depleted diet (<3 μg/g), a carotenoid‐rich diet (50 μg/g) within physiological range, or a carotenoid‐rich diet (100 μg/g xanthophylls) within pharmacological range for 17 weeks. We hypothesized that this range of dietary carotenoid dosages would differently affect oxidative damage, as measured by thiobarbituric acid reactive substances (TBARS), between species and sexes and among the tissues examined. Overall, liver and heart tissue exhibited the highest levels of oxidative damage, whereas adipose tissue had the lowest. We found that dietary xanthophyll (lutein and zeaxanthin) supplementation had no significant effect on tissue pro‐oxidation in males and females from both species. Moreover, for only two tissues (plasma and heart) did we find sex or species differences in oxidative stress. We did not find significant correlations in the levels of oxidative damage among plasma, liver, adipose, heart and breast muscle. In conclusion, the current study does not support a consistent antioxidant role for dietary carotenoids in the tissues of these two waterfowl species. Instead, our results align with the notion that carotenoids play complex, tissue‐specific roles in oxidative balance in birds.</jats:p><jats:p><jats:bold>Support or Funding Information</jats:bold></jats:p><jats:p>The authors thank the University of Poitiers, France for providing MG with a summer internship to help support this research. The larger study was funded by the National Science Foundation (grant numbers NSF/IOS‐0746364 and ‐0925633 to KJM).</jats:p><jats:p>This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in <jats:italic>The FASEB Journal</jats:italic>.</jats:p>