Osteoporosis, bone mineralization, and status of selected trace elements in two populations of moose calves in Norway

This study was conducted to clarify the etiology of a high frequency of bon e fractures and osteoporosis in the moose (Alces alces) population in south ern Norway Liver samples, both metacarpi, and carcass data were collected f rom 21 and 22 moose calves shot in 1994 in Birkenes (southern Norway), and Naeroy (central Norway), respectively. The liver samples were analyzed for copper, manganese, zinc, cobalt, chromium, molybdenum, and selenium. Bone s amples were subject to histologic, radiologic, and chemical examinations. T hree of the calves from Birkenes and one calf from Norway showed histologic and radiologic evidence of generalized osteoporosis consistent with osteop orosis due to starvation. The calves with osteoporosis had the lowest carca ss weights and radio-opacities recorded. There was a positive correlation b etween carcass weight and bone radio-opacity. Density, ash content, phospho rus, and calcium contents and phosphorous/calcium ratio in bone samples, as well as hepatic trace element status, were within the normal range for all calves in both populations. Two of the osteoporotic calves, were reported to have been orphaned. Our results indicate that the high frequency of bone fractures reported in moose in southern Norway is not associated with regi onal differences in trace element status or bone mineral balance. We propos e that the occurrence of osteoporosis in moose calves in Birkenes may have resulted from inadequate nutrition following general overcrowding and high pressure on feed resources in the southernmost part of Norway.