Fatty acid status in captive and free-ranging black rhinoceroses (Diceros bicornis)

It has been suspected that the fatty acid (FA) status of captive black rhinoceroses (Diceros bicornis) differs drastically from their free-ranging conspecifics, due to the difference in FA pattern between the natural forage and the captive diet. Natural forage of black rhinoceros, and temperate browse, contains a n-6/n-3 FA ratio (expressed as % of total FA) of 0.1-0.3. In contrast, zoo diets, assuming a hay:concentrate ratio of 61:28, have a n-6/n-3 ratio of 1.2. Therefore, significant differences in FA body composition between free-ranging and captive black rhinoceroses can be suspected.