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霉菌毒素是霉菌在次生代謝過程中生成的一類毒性物質(zhì)。谷物中霉菌毒素的污染會給養(yǎng)殖行業(yè)帶來眾多嚴(yán)重的經(jīng)濟(jì)損失。
多種霉菌毒素的存在會影響到食物在胃腸道內(nèi)的消化水平，影響人和動物的健康狀態(tài)，導(dǎo)致疾病甚至死亡。目前而言，世界已知的霉菌毒素種類超過400種。其中影響最為廣泛的霉菌毒素可以主要六類：黃曲霉毒素，單端孢霉烯族毒素，煙曲霉毒素，玉米赤霉烯酮，赭曲霉毒素和麥角類毒素。從營養(yǎng)的角度看，霉菌毒素與飼料的脂肪、蛋白質(zhì)、碳水化合物、維生素等具有較大的相關(guān)性。高脂飼料中對霉菌毒素具有抑制作用（mortality-sparing），但如果富含不飽和脂肪酸，則具有促擴(kuò)散作用（growth-sparing）。一些霉菌毒素會引起脂質(zhì)的吸收不良癥，同時也能減少消化酶和膽汁鹽的分泌，減少脂肪酸的合成，損害脂質(zhì)運輸通路。動物機(jī)體在缺乏維生素A、D或者核黃素時對霉菌毒素的敏感性增加，而在缺乏硫胺素（維生素B1）時敏感性降低。而霉菌毒素與維生素E、K的相關(guān)性目前尚未有明確的認(rèn)識。霉菌毒素增加了動物機(jī)體對蛋白質(zhì)的需求量，并且影響了動物機(jī)體內(nèi)調(diào)節(jié)糖原分解合成酶的活性。
飼料原料——霉菌毒素最主要的來源
霉菌毒素防控最切實可行的方法是在飼料進(jìn)入倉庫前采用快速診斷系統(tǒng)檢測飼料中霉菌毒素的含量。不同類型的快速診斷系統(tǒng)對于霉菌毒素的檢測均已有相關(guān)的驗證，這些診斷方式可以快速準(zhǔn)確地檢測出飼料中霉菌毒素的含量，從而避免給動物飼喂霉菌毒素超標(biāo)的飼料。如果配方中每種原料的霉菌毒素含量均已知曉，那么配方師可以根據(jù)這些毒素的含量水平來準(zhǔn)確設(shè)定添加脫霉劑的量。受到檢測實驗條件的限制，一般飼料企業(yè)會采用較為簡單快捷的霉菌毒素檢測方法如膠體金快速診斷試劑盒和ELISA檢測試劑盒。這類檢測試劑盒的優(yōu)勢在于能快速進(jìn)行大批量的飼料霉菌毒素診斷，但其檢測結(jié)果的準(zhǔn)確度受到諸多因素的影響，包括檢測試劑盒的質(zhì)量、樣品處理方式、檢測流程、人為操作等。如果檢測結(jié)果不精準(zhǔn)，那么根據(jù)霉菌毒素數(shù)據(jù)進(jìn)行的脫霉劑添加量調(diào)整也就沒有什么意義。為了保證檢測結(jié)果的準(zhǔn)確性，飼料企業(yè)有必要定期對常規(guī)檢測方法的檢測結(jié)果進(jìn)行進(jìn)一步的驗證。我們推薦飼料企業(yè)可以選擇具有專業(yè)霉菌毒素檢測服務(wù)的公司，對飼料檢測人員進(jìn)行系統(tǒng)化專業(yè)培訓(xùn)，定期對檢測試劑盒的精準(zhǔn)度進(jìn)行驗證，以避免飼料霉菌毒素超標(biāo)事故的發(fā)生。
終端飼喂中多種霉菌毒素的共存
另外一種霉菌毒素防控的措施是檢測終端飼料中霉菌毒素的含量。飼料企業(yè)一般僅檢測幾種重要原料的霉菌毒素含量，對于一些添加量較少或污染霉菌毒素概率較低的原料考慮到成本因素會忽略不檢測。然而這類用量較少或污染概率較低的飼料也有可能會大幅度增加飼料中霉菌毒素的含量。這種檢測終端飼料中霉菌毒素含量的方法可以幫助了解飼料產(chǎn)品的整體質(zhì)量。
霉菌抑制劑——有效抑制霉菌但不能控制霉菌毒素
企業(yè)可以通過各種措施來控制倉庫內(nèi)飼料溫度和水分含量，從而防止倉儲霉菌毒素的生成（赭曲霉毒素和黃曲霉毒素）。在倉桶條件不能保證安全的情況下，使用霉菌抑制劑會是一個很好的選擇。然而很多霉菌毒素在進(jìn)入倉庫前就已經(jīng)產(chǎn)生（例如單端孢霉烯族毒素），而且任何一種霉菌抑制劑都不能對霉菌毒素進(jìn)行降解。
有效的霉菌毒素管理
飼料霉菌毒素的最后一道防線是霉菌毒素脫毒劑。這類產(chǎn)品并不會在飼料倉儲或飼料加工環(huán)節(jié)產(chǎn)生作用，而主要是在動物體內(nèi)發(fā)揮功效。霉菌毒素脫毒劑在腸道內(nèi)會通過吸附霉菌毒素的某些官能團(tuán)來吸附霉菌毒素，或者通過生物酶解的方式將霉菌毒素降解。目前市場上較為常見的霉菌毒素脫毒劑往往會采用物理吸附、生物酶解和提高機(jī)體免疫抗氧化功能的方式來防控霉菌毒素。
Last but not least
飼料最終的消費者是動物，飼料企業(yè)所有關(guān)于霉菌毒素的工作都是為了給動物提供健康安全的飼料。因而對于霉菌毒素最有發(fā)言權(quán)的應(yīng)該是我們所養(yǎng)殖的動物。動物不會說話，但它們可以通過一些行為、癥狀或者病變來默默地向養(yǎng)殖者表達(dá)觀點。但我們往往會忽略掉這些細(xì)微的信息。
隨著科學(xué)的發(fā)展，科學(xué)家們已經(jīng)研制出了研究出一整套針對霉菌毒素敏感有效的診斷技術(shù)，包括分析肝、腎中霉菌毒素及其代謝產(chǎn)物的含量（科學(xué)家稱之為生物標(biāo)記物 biomarker）。這些生物標(biāo)記物不僅可從分子水平探討霉菌毒素對機(jī)體組織損傷的作用機(jī)制，而且在準(zhǔn)確、敏感地評價早期、低水平的損害方面有著獨特的優(yōu)勢，可提供早期預(yù)警，很大程度上為臨床獸醫(yī)師提供了輔助診斷的依據(jù)。這套診斷技術(shù)經(jīng)大量實驗數(shù)據(jù)證明有效，目前已經(jīng)被歐洲許多國家用于監(jiān)控器官中霉菌毒素限量。
The English version
Mycotoxin mold is generated in the process of secondary metabolism of toxic substances. Grain of mycotoxin contamination can bring many serious economic losses to aquaculture industry.
The existence of a variety of mycotoxin will affect the food in the digestive level in the gastrointestinal tract, affect human and animal health, causing disease and even death. For now, the world of mycotoxin known species more than 400 kinds. Which can influence most widely mycotoxin mainly six types: yellow aspergillus toxin, single-ended spore alkene toxins, smoke aspergillus toxin, corn gibberellic ketene, ochre and aspergillus toxin and ergot toxoid. From the nutritional point of view, mycotoxin and feed the fat, protein, carbohydrate, vitamin and so on has great relevance. High-fat diet has inhibitory effect on mycotoxin (mortality - sparing), but if is rich in unsaturated fatty acid, has its effect on promoting proliferation (growth - sparing). Some mycotoxins cause lipid malabsorption syndrome, but also can reduce the secretion of digestive enzymes and bile salt, reduce the number of fatty acid synthesis, damage of lipid transport pathways. Animal body in A lack of vitamin A, D, or when the riboflavin of mycotoxin sensitivity increases, and in the absence of thiamine (vitamin B1) reduced susceptibility. Mycotoxin and the correlation of vitamin E, and K has yet to have a clear understanding. Mycotoxin increased demand for animal organism on the protein, and affected the animal inside the body to adjust decomposition of glycogen synthase activity.
The most important source of feed ingredients, mycotoxins
Is the most practical methods in the prevention and control of mycotoxin feed before entering the warehouse using rapid diagnostic system testing of mycotoxins in feed content. Different types of rapid diagnostic system for detection of mycotoxin were related to verification, the diagnostic method can rapidly and accurately detect the content of mycotoxins in feed, to avoid to feeding mycotoxin excessive amounts of feed the animals. If mycotoxins of each raw material in the formula have been known, then the formula can accurately according to levels of these toxins are set up to add the amount of mildew agent. By detecting the limitation of experimental conditions, the general feed enterprises will use a relatively simple and quick mycotoxin detection methods such as colloidal gold rapid diagnostic kit and ELISA test kit. Such detection kit has the advantage of large quantities of feed mycotoxins diagnosis quickly, but the accuracy of the test results affected by many factors, including the quality of detection kits, sample processing method, test process, the artificial operation and so on. If test result is not accurate, then according to the data of mycotoxin mildew remover content adjustment also have no meaning. In order to ensure the accuracy of the test results, feed enterprise is necessary to regularly test results of conventional detection methods for further verification. We recommend feed enterprises can choose to have professional mycotoxin testing services company, systematic professional training, feed testing personnel on a regular basis to certify the accuracy of detection kits, to avoid excessive feed mycotoxins accidents.
Terminal feeding in a variety of coexistence of mycotoxin
Another is the measures of prevention and control of mycotoxin detection terminal of mycotoxins in feed content. Feed enterprises are generally only to detect the contents of several kinds of important raw material of mycotoxin, for some add less or pollution mycotoxin probability of lower raw materials considering the cost factor will be ignored. However such amount or less pollution probability lower feed are also likely to be substantially increase the amount of mycotoxins in feed. This method of detection terminal content of the mycotoxins in feed can help understand the overall quality of the feed products.
Mould inhibitor -- but not effective inhibitory control mycotoxin
Enterprise can through a variety of measures to control the warehouse of feed temperature and moisture content, so as to prevent the warehouse of mycotoxin generated (ochre and aspergillus toxin and aflatoxin). Under the condition of the warehouse barrels cannot guarantee safety, use mould inhibitor can be a good choice. But a lot of mycotoxin were produced before entering the warehouse (single-ended spore of alkene toxins, for example), and any kind of mould inhibitor can degradation of mycotoxin.
Effective management of mycotoxin
Feed mycotoxins of the last line of defense is a mycotoxin poison. This kind of product will not be in storage or feed feed processing link, and mainly function in animal body. Mycotoxin poison off in the gut will pass some functional groups of mycotoxin to adsorption mycotoxin, or through the mycotoxin degradation enzyme solution way. More common on the market at present the mycotoxin poison off often using physical adsorption, biological enzymolysis and improve the body's immune to prevention and control mycotoxin antioxidant function.
Last but not least
The final consumer is animal feed, feed enterprises all works about mycotoxins are to provide health and safety of feed for animals. Thus the mycotoxin most voice should be that we farmed animals. Animals can't talk, but they can pass some behavior to the farmers, the symptoms or lesion to silently. But we tend to ignore these subtle messages.
With the development of science, scientists have developed a developed a set of mycotoxin sensitive and effective diagnosis technology, including the analysis of mycotoxins in liver, kidney and its metabolite levels (scientists call them biomarkers biomarker). These biomarkers can be not only from the molecular level to study the effect of mycotoxin on tissue damage mechanism, and early in the accurate, sensitive evaluation, the low level of damage has a unique advantage, can provide early warning, to a large extent for clinical veterinary provides auxiliary diagnosis basis. The diagnosis technology of a lot of experimental data show that effective, at present has been in many European countries used to monitor organs in mycotoxin.
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