25-OH-D(3), calcium, phosphorus, and alkaline phosphatase content in sera from captive polar bear (Ursus maritimus) cubs at the Denver Zoological Foundation.
After the development of rickets in two hand-reared polar bear (Ursus maritimus) cubs at the Denver Zoological Foundation we initiated a project opportunistically evaluating sera 25-OH-D(3), calcium, phosphorus, and alkaline phosphatase levels in seven mother-reared polar bear cubs. From one to three serum samples were obtained while the cub was still in the den with no access to natural sunlight and one after the cub exited the den. The sera 25-OH-D(3) increased as the cubs grew (108+/-37 nmol/L [n=7] while in den, 184.6+/-48.3 nmol/L [n=7] out of the den) but were substantially lower then captive adults (348+/-215 nmol/L [n=36]) or free-ranging adults (360+/-135 nmol/L [n=56]). We found that age was correlated significantly with 25-OH-D(3) levels but den status (in or out) was not significant. Sera calcium and phosphorus values were highest in denned cubs (calcium, 2.9+/-0.4 mmol/L [n=13]; phosphorus, 3.1+/-0.5 mmol/L [n=13]) and then declined as the cubs matured and left the den (calcium, 2.5+/-0.1 mmol/L [n=7]; phosphorus, 2.4+/-0.4 mmol/L [n=7]). The enzyme alkaline phosphatase (presumably the bone isoenzyme) was high in denned growing cubs (831+/-426 IU/L [n=13]) and then declined gradually as the cubs aged and exited the den (96+/-83 IU/L [n=7]). Zoo Biol 0:1-7, 2007. (c) 2007 Wiley-Liss, Inc.
Kenny
David E
DE
Animal Health Department, Denver Zoological Foundation, Denver, Colorado.