Louisiana State University School of Veterinary Medicine, Baton Rouge, LA 70803,
Louisiana State University School of Veterinary Medicine, Baton Rouge, LA 70803.
Avian Dis. 2022 Jun;66(2):148-154. doi: 10.1637/aviandiseases-D-21-00117. Epub 2022 Apr 27.
Vitamin D is a hormone that can be ingested or synthesized in the body when skin is exposed to ultraviolet radiation (UV), typically from sunlight. In captivity, birds with no sunlight exposure may develop vitamin D deficiencies that may contribute to hypocalcemic conditions, even when fed a diet supplemented with vitamin D. An initial pilot study with Hispaniolan Amazon parrots () conducted approximately 18 mo prior indicated there were significant differences in the 25-hydroxyvitamin D (vit D) plasma levels between the resident parrots (indoor-only housing) and a new group of historically outdoor-housed parrots (new parrots) 5 days after the arrival of the latter at our institution. The goals of this study were to determine if vit D, ionized calcium (Ca), and ionized magnesium (Mg) levels changed from baseline values (taken 18 mo prior) in the new birds as well as to compare those values to those of the resident birds over time. The treatment was a change in husbandry for the new parrots (no UV exposure and diet as provided for the resident parrots). To accomplish this, the authors compared vit D levels in the same two groups of birds that were fed the same vit D-fortified diet and given no access to natural or artificial UV light exposure for 18 mo. The resident parrots ( = 9) had been housed indoors for approximately 20 yr with no exposure to natural or supplemented UV light. The second group of birds (new parrots; = 8) had been housed outdoors prior to the initiation of the pilot study in 2016 and were fed a similar-but not identical-diet prior to their arrival. Plasma samples were sent to the Michigan State University Diagnostic Center for Population and Animal Health for analysis. Test results demonstrated differences between the two groups of parrots, largely attributed to the decrease in vit D plasma levels in the new parrots over time to values equivalent to those measured in the resident birds. Differences were seen in plasma Ca, while no differences were demonstrated relative to Mg. We discuss these findings and suggest that plasma vit D levels decrease in the absence of UV light, even when animals are maintained on a vit D-fortified and balanced diet.
维生素 D 是一种激素，当皮肤暴露在紫外线（UV）下时，身体可以摄入或合成，通常来自阳光。在圈养环境中，没有阳光照射的鸟类可能会出现维生素 D 缺乏症，即使喂食添加了维生素 D 的饮食，也可能导致低钙血症。大约在 18 个月前，对伊斯帕尼奥拉亚马逊鹦鹉（）进行的一项初步试点研究表明，在后者抵达我们机构后的第 5 天，在居住鹦鹉（仅限室内饲养）和一组新的历史上户外饲养的鹦鹉（新鹦鹉）之间，25-羟维生素 D（vit D）血浆水平存在显著差异。本研究的目的是确定新鸟类的 vit D、离子钙（Ca）和离子镁（Mg）水平是否从 18 个月前的基线值（基线值）发生变化，以及随着时间的推移，将这些值与居住鸟类进行比较。治疗方法是改变新鹦鹉的饲养方式（无紫外线暴露和为居住鹦鹉提供的饮食）。为此，作者比较了喂食相同强化维生素 D 饮食且 18 个月内无自然或人工紫外线照射的两组鸟类的 vit D 水平。居住的鹦鹉（=9）已经在室内饲养了大约 20 年，没有暴露在自然或补充的紫外线光下。第二组鸟类（新鹦鹉；=8）在 2016 年开始试点研究之前一直被饲养在户外，在抵达之前，它们一直食用类似但不完全相同的饮食。血浆样本被送到密歇根州立大学诊断中心进行种群和动物健康分析。测试结果表明两组鹦鹉之间存在差异，主要归因于新鹦鹉的 vit D 血浆水平随时间的推移而降低，其值与居住鸟类的测量值相当。在血浆 Ca 中观察到差异，而在 Mg 方面没有差异。我们讨论了这些发现，并认为即使动物维持在强化和平衡的维生素 D 饮食中，在没有紫外线的情况下，血浆维生素 D 水平也会下降。
