Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, P.O. Box 57, 00014, Finland.
Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Winterthurerstr. 260, Zurich 8057, Switzerland.
Vet J. 2024 Aug;306:106149. doi: 10.1016/j.tvjl.2024.106149. Epub 2024 May 28.
Rabbits kept under ultraviolet B (UVB)-irradiation respond with increasing serum vitamin D (25(OH)D) concentrations, but it is unknown whether irradiation of the animals or their feed contributes more. Twenty-four New Zealand White rabbits were divided into three groups for a four-week period: the control group (C) received no UVB-exposure and non-irradiated hay (ergocalciferol (vitamin D) concentration 2.22 µg/100 g dry matter). The direct exposure group (D) was provided with 12 h of UVB-irradiation daily and fed the same hay as group C in shaded areas to prevent UVB-irradiation thereof. The indirect exposure group (I) did not receive direct UVB-irradiation but was fed hay of the same batch that was exposed to 12 h of UVB-irradiation (vitamin D 6.06 µg/100 g dry matter). Serum 25(OH)D, 25(OH)D, ionised calcium, total calcium, phosphorus, and magnesium concentrations were measured weekly. There was no systematic effect on serum mineral concentrations. The serum 25(OH)D concentrations were significantly higher in group I compared to groups C and D from the second week onwards. 25(OH)D concentrations increased only in group D, with significant differences to both other groups from the third week onwards, yet at lower magnitudes than the noted increase of 25(OH)D in group I. Total 25(OH)D concentrations were highest in group I, intermediate in group D and lowest in group C. Serum total 25(OH)D concentration was more affected by UVB-irradiation of rabbits' feed than by direct irradiation of the animals themselves. If rabbit serum total 25(OH)D concentrations should be managed, diet manipulation rather than animal UVB-exposure appears to be more effective.
兔在紫外线 B（UVB）照射下会增加血清维生素 D（25（OH）D）浓度，但尚不清楚是照射动物还是其饲料的作用更大。24 只新西兰白兔分为三组，进行为期四周的实验：对照组（C）不接受 UVB 照射，也不接受辐照干草（麦角钙化醇（维生素 D）浓度为 2.22μg/100g 干物质）。直接照射组（D）每天接受 12 小时的 UVB 照射，并在阴凉处喂食与 C 组相同的干草，以防止其受到 UVB 照射。间接照射组（I）不接受直接 UVB 照射，但喂食相同批次的干草，该干草接受了 12 小时的 UVB 照射（维生素 D 为 6.06μg/100g 干物质）。每周测量血清 25（OH）D、25（OH）D、离子钙、总钙、磷和镁浓度。血清矿物质浓度没有系统影响。从第二周开始，与 C 组和 D 组相比，I 组的血清 25（OH）D 浓度明显更高。只有 D 组的 25（OH）D 浓度增加，与其他两组相比，从第三周开始有显著差异，但增加幅度低于 I 组。I 组的总 25（OH）D 浓度最高，D 组次之，C 组最低。血清总 25（OH）D 浓度受兔饲料 UVB 照射的影响大于动物本身的直接照射。如果要控制兔血清总 25（OH）D 浓度，饮食控制似乎比动物 UVB 暴露更有效。
