Gimmel Angela Emilia Ricarda, Baumgartner Katrin, Liesegang Annette
Institute of Animal Nutrition, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 270, 8057, Zurich, Switzerland.
Zoo Nuremberg, Am Tiergarten 30, 90480, Nuremberg, Germany.
BMC Vet Res. 2016 Sep 5;12(1):180. doi: 10.1186/s12917-016-0818-1.
As fish eaters bottlenose dolphins (Tursiops truncatus) in human care need to receive daily vitamin supplementation, because whole thawed fish lacks certain vitamins. However, the exact concentration of supplementation has not been established and is a matter of discussion. To ensure adequate vitamin supplementation in pets, vitamin blood concentrations are measured. This is not a common practice in dolphins. The objective of the present study was to collect information about vitamin supplementation in bottlenose dolphins and on vitamin blood concentrations of healthy animals in European facilities. In addition, these results were compared with blood levels of wild animals. Conclusions on how to provide bottlenose dolphins in human care with an effective vitamin supplementation will then be drawn. Initially, fish-handling techniques and vitamin supplementation were evaluated by questionnaire, which was sent to 25 European facilities that house bottlenose dolphins. Secondly, blood samples from 57 dolphins living in 10 facilities were taken and sent by mail to a reference laboratory. They were analysed for retinol, thiamine pyrophosphate, cobalamin, calcidiol and tocopherol. The blood concentrations were then correlated with vitamin supplementation, fish handling techniques and pre-existing blood concentrations of free-ranging dolphins. Finally, the data was subjected to a standard analysis of variance techniques (ANOVA) and a linear model analysis.
Fish was mainly thawed in a refrigerator. Further, the 95 % confidence interval for retinol blood concentrations was 0.048 to 0.059 mg/l and for tocopherol 17.95 to 20.76 mg/l. These concentrations were 27 and 53 %, respectively, higher than those found in free-ranging animals. In contrast, calcidiol concentrations (143.9-174.7 ng/ml) of the dolphins in human care were lower than in blood found for free-ranging animals. Regarding thiamine pyrophosphate and cobalamin, concentrations ranged between 0.42 and 0.55 mg/l and 175.55 and 275.22 pg/ml respectively. No reference concentrations for free-ranging Tursiops truncatus were found.
These findings suggest an over-supplementation of retinol (vitamin A) and tocopherol (vitamin E) in bottlenose dolphins (Tursiops truncatus) housed in human care. Therefore, vitamin A supplementation should not exceed 50,000 IU per animal per day and vitamin E supplementation should be around 100 IU per kg fed fish per day.
作为食鱼动物，人工饲养的宽吻海豚（瓶鼻海豚）需要每日补充维生素，因为解冻后的整条鱼缺乏某些维生素。然而，具体的补充浓度尚未确定，仍是一个讨论的问题。为确保宠物获得足够的维生素补充，会检测血液中的维生素浓度。这在海豚中并不常见。本研究的目的是收集有关欧洲人工饲养宽吻海豚维生素补充情况以及健康动物血液中维生素浓度的信息。此外，将这些结果与野生动物的血液水平进行比较。然后得出关于如何为人工饲养的宽吻海豚提供有效维生素补充的结论。最初，通过问卷调查对鱼类处理技术和维生素补充情况进行评估，问卷发送给了25家饲养宽吻海豚的欧洲机构。其次，采集了来自10家机构的57只海豚的血样，并通过邮寄方式送到一家参考实验室。对血样进行视黄醇、硫胺素焦磷酸、钴胺素、骨化二醇和生育酚的分析。然后将血液浓度与维生素补充情况、鱼类处理技术以及野生海豚先前的血液浓度进行关联。最后，对数据进行标准方差分析技术（ANOVA）和线性模型分析。
鱼主要在冰箱中解冻。此外，视黄醇血液浓度的95%置信区间为0.048至0.059毫克/升，生育酚为17.95至20.76毫克/升。这些浓度分别比野生海豚高出27%和53%。相比之下，人工饲养海豚的骨化二醇浓度（143.9 - 174.7纳克/毫升）低于野生海豚血液中的浓度。关于硫胺素焦磷酸和钴胺素，浓度分别在0.42至0.55毫克/升和175.55至275.22皮克/毫升之间。未找到野生宽吻海豚的参考浓度。
这些发现表明，人工饲养的宽吻海豚存在视黄醇（维生素A）和生育酚（维生素E）补充过量的情况。因此，维生素A的补充量不应超过每只动物每天50,000国际单位，维生素E补充量应为每天每千克投喂的鱼100国际单位左右。
