van Sonsbeek Gerda R, van der Kolk Johannes H, van Leeuwen Johannes P T M, Everts Hendrik, Marais Johan, Schaftenaar Willem
Faculty of Veterinary Medicine, Department of Equine Sciences, Medicine Section, University of Utrecht, Postbus 80163, 3508TD Utrecht, The Netherlands.
J Zoo Wildl Med. 2013 Sep;44(3):529-40. doi: 10.1638/2010-0123R4.1.
The aim of the current study was to assess the effect of oral calcium and cholecalciferol supplementation on several parameters of calcium status in plasma and urine of captive Asian (Elephas maximus; n=10) and African elephants (Loxodonta africana; n=6) and to detect potential species differences. Calcium and cholecalciferol supplementation were investigated in a feeding trial using a crossover design consisting of five periods of 28 days each in summer. From days 28-56 (period 2), elephants were fed the Ca-supplemented diet and from days 84-112, elephants were fed the cholecalciferol-supplemented diet (period 4). The control diet was fed during the other periods and was based on their regular ration, and the study was repeated similarly during winter. Periods 1, 3, and 5 were regarded as washout periods. This study revealed species-specific differences with reference to calcium and cholecalciferol supplementation. Asian elephants showed a significant increase in mean plasma total calcium concentration following calcium supplementation during summer, suggesting summer-associated subclinical hypocalcemia in Western Europe. During winter, no effect was seen after oral calcium supplementation, but a significant increase was seen both in mean plasma, total, and ionized calcium concentrations after cholecalciferol supplementation in Asian elephants. In contrast, evidence of subclinical hypocalcemia could be demonstrated neither in summer nor in winter in African elephants, although 28 days of cholecalciferol supplementation during winter reversed the decrease in plasma 1,25(OH)2-cholecalciferol and was followed by a significant increase in mean plasma total calcium concentration. Preliminary findings indicate that the advisable permanent daily intake for calcium in Asian elephants and cholecalciferol in both elephant species at least during winter might be higher than current guidelines. It is strongly recommended to monitor blood calcium concentrations and, if available, blood parathyroid hormone levels to adjust the nutritional supplementation for each individual elephant.
本研究的目的是评估口服钙和胆钙化醇补充剂对圈养亚洲象（印度象；n = 10）和非洲象（非洲象；n = 6）血浆和尿液中钙状态的几个参数的影响，并检测潜在的物种差异。在夏季进行了一项喂养试验，采用交叉设计，包括五个为期28天的阶段，对钙和胆钙化醇补充剂进行了研究。从第28 - 56天（第2阶段），大象喂食补充钙的饮食，从第84 - 112天，大象喂食补充胆钙化醇的饮食（第4阶段）。在其他阶段喂食对照饮食，该饮食基于它们的常规定量，并且在冬季以类似方式重复该研究。第1、3和5阶段被视为洗脱期。本研究揭示了在钙和胆钙化醇补充方面的物种特异性差异。亚洲象在夏季补充钙后，平均血浆总钙浓度显著增加，这表明在西欧存在与夏季相关的亚临床低钙血症。在冬季，口服补钙后未观察到效果，但亚洲象补充胆钙化醇后，平均血浆总钙和离子钙浓度均显著增加。相比之下，非洲象在夏季和冬季均未显示亚临床低钙血症的证据，尽管在冬季补充28天胆钙化醇可逆转血浆1,25(OH)2 - 胆钙化醇的下降，并随后平均血浆总钙浓度显著增加。初步研究结果表明，至少在冬季，亚洲象的建议每日钙摄入量以及两种象的胆钙化醇摄入量可能高于当前指南。强烈建议监测血钙浓度，并在可行时监测血甲状旁腺激素水平，以调整每头大象的营养补充。
