Department of Environmental Biotechnology, Faculty of Environmental Sciences, University of Warmia and Mazury in Olsztyn, ul. Słoneczna 45G, 10-709, Olsztyn, Poland.
Department of Veterinary Prevention and Feed Hygiene, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, ul. Oczapowskiego 13, 10-950, Olsztyn, Poland.
Fish Shellfish Immunol. 2019 Jan;84:680-694. doi: 10.1016/j.fsi.2018.10.032. Epub 2018 Oct 22.
To investigate the effects of feed contamination with zearalenone (ZEN) at the current European Commission (EC) guidance value (2 mg⋅kg feed) on the growth and health of rainbow trout, we performed a long-term feeding trial under aquaculture conditions. It started with the external feeding of the fish larvae, and continued for 96 weeks, at which point the fish had reached market size. To assess the growth of fish and their feeding efficiency throughout this period, the fish were regularly weighed and measured, and their feed consumption was monitored. Additionally, to investigate potential health effects, after 72 weeks of the exposure to ZEN, the fishes' blood was analyzed for major hematological and biochemical indices, and their head kidney, spleen, and liver were examined for morphological, histopathological, cytological, and molecular changes. Finally, to gain insight into the metabolism and distribution of ZEN in fish, the content of free and glucuronidated forms of ZEN and its major metabolites was measured in the intestine, liver, and muscles of the exposed fish. The feed-borne exposure of rainbow trout to ZEN at a dose of 2 mg⋅kg feed resulted in higher feeding efficiency and growth rate, most probably due to the anabolic properties of the ZEN metabolite. Importantly for the consumers of fish, despite absorption and metabolism of ZEN in the digestive system of the fish that had been exposed for 72 weeks, the residuals of ZEN were not transferred to the fishes' muscles, which rules out a potential risk to human health related to the consumption of fish meat. However, the increased growth of fish fed with the contaminated feed may come at some cost, as the exposure to ZEN was associated with modulation of key components of the adaptive and innate immune systems. Moreover, the trunk kidney of ZEN-fed fish showed massive inflammation that was likely caused by pathogen infection. These findings raise concerns about fish health under the current recommended EC guidance values.
为了研究在欧盟委员会（EC）现行指导值（饲料中 2 毫克/千克）下，玉米赤霉烯酮（ZEN）污染饲料对虹鳟生长和健康的影响，我们在水产养殖条件下进行了一项长期喂养试验。该试验从鱼苗的外部喂养开始，持续了 96 周，此时鱼已经达到了市场大小。为了评估整个过程中鱼的生长和摄食效率，我们定期对鱼进行称重和测量，并监测其饲料消耗。此外，为了研究潜在的健康影响，在暴露于 ZEN 72 周后，分析了鱼类的血液中的主要血液学和生物化学指标，并检查了其头肾、脾脏和肝脏的形态、组织病理学、细胞学和分子变化。最后，为了深入了解 ZEN 在鱼类中的代谢和分布，测量了暴露于 ZEN 的鱼的肠道、肝脏和肌肉中 ZEN 的游离和结合形式及其主要代谢物的含量。以 2 毫克/千克饲料剂量通过饲料途径对虹鳟进行 ZEN 暴露，导致更高的摄食效率和生长速度，这很可能是由于 ZEN 代谢物的合成代谢特性。对鱼类消费者来说重要的是，尽管暴露于 ZEN 的鱼的消化系统中吸收和代谢了 ZEN，但 ZEN 的残留并未转移到鱼类的肌肉中，这排除了与食用鱼肉相关的人类健康潜在风险。然而，由于受到污染的饲料增加了鱼的生长，可能会带来一些代价，因为暴露于 ZEN 与适应性和先天免疫系统的关键成分的调节有关。此外，ZEN 喂养的鱼的中肾显示出大量的炎症，这很可能是由病原体感染引起的。这些发现引起了人们对现行 EC 建议值下鱼类健康的关注。
