The effect of length of cold storage on secondary plant compounds in browse for captive black rhinoceros (Diceros bicornis)
Citation
Hunt A, Reppert A, Spears K, Eyres A. 2007. The effect of length of cold storage on secondary plant compounds in browse for captive black rhinoceros (Diceros bicornis). In Ward A, Hunt A, Maslanka M, Eds. Proceedings of the Seventh Conference on Zoo and Wildlife Nutrition, AZA Nutrition Advisory Group, Knoxville, TN.
Abstract
The endangered black rhinoceros (Diceros bicornis) suffers from a high rate of mortality in captivity due to conditions such as hemosiderosis and hemolytic anemia. Supplementation of the diet with native browse species rich in tannins and other iron-binding polyphenolics has been proposed as a dietary strategy for reducing iron absorption and accumulation in this population. This study examined the effect of cold storage versus fresh material on iron binding polyphenolic (IBP) and iron binding tannin (IBT) contents of a North American browse species, prairie sumac (Rhus lanceolata). Leaves and stems of prairie sumac were collected fresh or stored in a cooler (-15°C) for up to one year. Fresh and frozen samples were analyzed for total IBP and IBT content. IBP and IBT levels in both stored and fresh leaves reached peak accumulation at day 21. IBP and IBT in stored leaves demonstrated significant decreases thereafter until day 70 (2.32 mgE gallic acid/g dry matter and 1.42 mgE gallic acid/g dry matter, respectively); no further significant changes in IBP content observed from days 70 to 365. No statistically significant differences in IBP or IBT over time were detected in or between stored and fresh stems. Though there were significant changes in the leaves, after day 70, the concentrations tended to be similar to that of the stems (1 – 2 mg equivalents gallic acid/gram dry plant). These findings indicate that cold storage of this browse species is a possible option for dietary supplementation of iron-binding compounds to captive black rhinoceros to reduce iron accumulation in this population.
Hunt – EFFECT OF LENGTH OF COLD STORAGE ON SECONDARY PLANT COMPOUNDS IN BROWSE FOR CAPTIVE BLACK RHINOCEROS {DICEROS BICORNIS).pdf 2 MB
