Apparent digestibility of macro-nutrients in captive polar bears

Source: Zool. Garten N.F. 73 (2003) 2, S 111-115
The diet of the polar bear (Ursus maritimus) under captive conditions differs from that in the wild. The wild polar bear feeds itself predominantly on the ringed seal (Phoca hispida), but they may also eat birds, grasses, moss and berries.
Polar bears prefer to hunt seals but they cannot successfully do so from shore during periods of open water and then they have to convert to other feeds. After a polar bear has killed a seal, it feeds predominantly on the blubber and often abandons the meat. In zoos, it is not possible to provide the polar bears with ringed seal. Mixtures of slaughter by-products, vegetables and commercial dog food are often supplied. This study presents data on the digestibility of a mixed ration in three captive polar bears. The polar bears consumed a diet containing 378 g crude fat and 356 g crude protein/kg DM. Crude protein digestibility was about 93% of intake. Apparent digestibility of crude fat was 95% of intake. The calculated average daily energy intake with protein, fat and non-structural carbohydrates by the polar bears was 46 MJ metabolisable energy per animal, which is equivalent to 790 kJ (188 kcal)/kg metabolic weight. The data collected may be used in evaluating and formulating rations for captive polar bears.

Title: Apparent digestibility of macro-nutrients in captive polar bears (Ursus maritimus)
Authors: Jansen, W.L., Bos, J., Veldhuis Kroeze, E.J.B., Wellen, A., Beynen, A.C.