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

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 (non-released 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 compared with either non-released 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 non-released captive-raised birds. Of the carotenoids evaluated, β-carotene was lower in livers from captive-raised birds compared with wild prairie-chickens. Zeaxanthin was lowest in livers from birds that were captive-raised but non-released. Differences in hepatic nutrient concentration among the three study groups may be directly correlated with dietary ingredients. 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.