Liver Fatty Acid, Mineral, and Fat-Soluble Nutrients in Wild and Captive Greater Prairie-Chickens

Abstract

Abstract We measured fatty acids, minerals, and fat-soluble nutrients in liver tissues from greater prairie-chickens Tympanuchus cupido pinnatus as an ecological dietary surrogate for endangered Attwater's prairie-chickens T. c. attwateri and investigated differences associated with captive (nonreleased captive raised; n = 4), wild (n = 12), and combination (released captive raised; n = 5) diets. In general, we found more variability across all fatty acids in samples from released captive-raised birds than in samples from either nonreleased captive-raised or wild birds. Polyunsaturated fatty acids were lowest in captive-raised birds. Regarding minerals, liver sodium values were uniquely lower in released captive-raised birds, and copper and manganese concentrations were lower for both released and nonreleased captive-raised birds. Of the carotenoids that we evaluated, β-carotene was lower in livers from captive-raised birds than in livers from wild prairie-chickens. Zeaxanthin was lowest in livers from birds that were captive raised but nonreleased. Differences in hepatic nutrient concentration among the three study groups may be directly correlated with dietary ingredients. Our results suggest possible management actions for improved nutrition of prairie-chickens in future release programs, such as further refinement of trace mineral and β-carotene content of captive commercial diets, the addition of supplemental feeds in release protocols that include an elevated polyunsaturated fatty acid profile, green plant materials that elevate β-carotene content, provision of trace mineralized salt sources at release sites, and timing releases to coincide with periods of high natural resource availability to better duplicate nutrient diversity.