業(yè)內(nèi)都知道霉菌毒素的問題是中國飼料原料乃至全球飼料原料，或者是我們?cè)陴B(yǎng)殖過程中碰到的最大的問題。關(guān)于霉菌毒素的消除，霉菌毒素吸附劑是一個(gè)比較好的方法，吸附劑價(jià)格從幾元錢到幾十元錢，甚至上百元錢每千克，價(jià)格差這么大，到養(yǎng)殖中到底能起多大的效果?今天在這里，我簡單分享一下霉菌毒素吸附劑的評(píng)估方法，以及添加劑、防霉劑等等問題。
霉菌毒素吸附劑的評(píng)估
在中國農(nóng)業(yè)部的三個(gè)目錄中是沒有霉菌毒素吸附劑這個(gè)條款的，美國也沒有，歐洲也沒有，在飼料工業(yè)術(shù)語中也沒有這個(gè)詞，這個(gè)詞僅用于商業(yè)和學(xué)術(shù)上的討論。霉菌毒素吸附劑在官方上也沒有得到認(rèn)可，最大的問題就是很多飼料企業(yè)到農(nóng)業(yè)部去反應(yīng)，說自己按照霉菌毒素吸附劑廠家的檢測和建議，添加了霉菌毒素吸附劑之后，飼料被官方抽查，檢測結(jié)果不合格，把吸附劑的廠家告到農(nóng)業(yè)部去了。農(nóng)業(yè)部專門對(duì)這方面做了解釋，是因?yàn)槲絼┰谵r(nóng)業(yè)部沒有被認(rèn)可，這是第一個(gè)問題。
第二點(diǎn)，關(guān)于吸附劑的作用，很受關(guān)注，褒貶不一。它的評(píng)估方法有體內(nèi)和體外兩類，體內(nèi)評(píng)估的方法很難說得清楚，體外的方法，所有賣霉菌毒素吸附劑的廠家到飼料公司做宣傳時(shí)都能給出很好的數(shù)據(jù)，但一個(gè)科學(xué)的方法一定要證明飼料原料霉菌毒素是如何轉(zhuǎn)移的，這一點(diǎn)要說清楚，能證實(shí)，這個(gè)評(píng)估的方法才是有效的方法。
現(xiàn)在被吸附劑廠家所普遍采用的方法是這樣的：基本上把霉菌毒素的標(biāo)樣游離，加入到緩沖溶液中，加上毒素吸附劑，經(jīng)過振動(dòng)、離心、分離，取上清。我認(rèn)為這樣的數(shù)據(jù)最大的好處是操作簡單，但是這脫離了實(shí)際的情況，因?yàn)槊咕舅卦谖覀兊娘暳现�、或者飼料原料中并不是以游離狀態(tài)存在的，或者說游離存在的只是一部分，還由一部分是結(jié)合態(tài)的，如果這樣的評(píng)估是加了一個(gè)游離毒素的標(biāo)樣，這樣的數(shù)據(jù)和實(shí)際是相差甚遠(yuǎn)的。
有一些廠家也看到了前一個(gè)方法的問題，第二個(gè)方法進(jìn)行了一定改進(jìn)，叫做空白基質(zhì)的方法。取一個(gè)空白基質(zhì)，比如說玉米或者淀粉，這里面是不含任何毒素的，加上標(biāo)準(zhǔn)樣品，實(shí)際上就加了一定的干擾，再把這些東西加到緩沖濃液里面去，經(jīng)過振蕩、離心，同樣認(rèn)為上清液中毒素的減少是吸附的數(shù)量。這個(gè)時(shí)候我們認(rèn)為它跟現(xiàn)實(shí)的原料情況還是不一樣，雖然增加了干擾因子，但這個(gè)數(shù)據(jù)還不是很可靠。
新方法試驗(yàn)
基現(xiàn)在廠家給我們提供的方法是這樣，我們自己通過這幾年的摸索形成了另一個(gè)方法，我們認(rèn)為毒素的吸附或者毒素跟原料是有結(jié)合力的，吸附劑必須把毒素跟原料的蛋白或者淀粉的結(jié)合力破壞掉，形成一種結(jié)合物，這個(gè)結(jié)合物在腸液或者胃液中不被解析，通過這個(gè)途徑，我們就做了一個(gè)已知毒素含量的天然底物，然后加上吸附劑，通過仿生消化的方法，讓毒素和吸附劑形成一個(gè)結(jié)合物，再經(jīng)過分離。這個(gè)方法的創(chuàng)新點(diǎn)，就是把霉菌毒素吸附劑加進(jìn)去以后，可以把毒素能夠分離出來，把吸附劑分離進(jìn)來，能明確指出霉菌毒素從原料中轉(zhuǎn)移到什么地方去了。我們幾乎用了一年半的時(shí)間想分離的方法，最后攻克了分離這個(gè)難點(diǎn)。但是現(xiàn)在看來，吸附劑的回收率只能做到75%左右，還不是很理想，有待進(jìn)一步的提高。我認(rèn)為這樣一個(gè)毒素轉(zhuǎn)移的過程，能把它講清。
用這樣的方法，我們看它對(duì)霉菌毒素的吸附。選擇一個(gè)被黃曲霉素污染的棉粕，測定空白時(shí)的數(shù)據(jù)，然后加蒙脫石，進(jìn)行體外消化，把棉粕和蒙脫石分離出來，分離出來的蒙脫石就能達(dá)到80ppb左右。經(jīng)過分離以后，黃曲霉毒素都轉(zhuǎn)移到分離出的吸附劑里了。再看牛的飼料，前面是按每噸5千克添加的，現(xiàn)在有這樣一個(gè)添加方式，就是按照0.1千克、0.3千克，1千克，3千克，5千克，7.5千克，10千克，每噸飼料按這樣的比例添加，沒有添加前牛的飼料是54ppb，在不同添加比例的時(shí)候，牛的飼料經(jīng)過分離，毒素含量明顯下降，加到5千克到7.5千克的時(shí)候，吸附力上升的數(shù)據(jù)就比較低了，一般都是在5千克上下，這是一個(gè)比較好的吸附。
不同廠家的吸附劑，對(duì)黃曲霉毒素，對(duì)嘔吐毒素，對(duì)赤霉烯酮，最后的結(jié)果不同，包括蒙脫石在內(nèi)的對(duì)黃曲霉毒素的吸附還算是比較有效，好的話能做到70左右，對(duì)嘔吐毒素跟赤霉烯酮的吸附，按我們這個(gè)方法做出來的效果是非常有限的，就是嘔吐毒素好的廠家能做到25左右，赤霉烯酮做到20左右。
霉菌毒素吸附劑的選擇
通過這些數(shù)據(jù)我們能看到一些什么?第一是關(guān)于毒素吸附劑的問題，雖然官方?jīng)]認(rèn)可，但是商品化的只有它能做，其他的不行。但是評(píng)價(jià)方法確實(shí)沒有公認(rèn)的標(biāo)準(zhǔn)，直接加標(biāo)樣，緩沖液的吸附效果是比較好，數(shù)據(jù)也非常漂亮，但是那個(gè)數(shù)據(jù)是被夸大的，實(shí)際上無論是養(yǎng)殖企業(yè)，還是飼料企業(yè)，大家在生產(chǎn)實(shí)踐中看到的也是同樣的，對(duì)嘔吐毒素，對(duì)赤霉烯酮的消除，無論用什么樣的方法，在實(shí)踐中都非常非常有限。通過這個(gè)實(shí)驗(yàn)我們得到的結(jié)論是，對(duì)常見的霉菌毒素，如果采用吸附劑的方法，對(duì)黃曲霉毒素是有效的。這種有效我需要花多少錢能做到的呢?3塊5塊錢的蒙脫石就足夠了，沒必要錢幾十塊錢達(dá)到這樣的效果。如果你想把赤霉烯酮和嘔吐毒素有效降低，現(xiàn)在靠吸附的方法是不可能的，是非常有限的，充其量也就是降低20-30，如果你想降低的話唯一的方法就是買好的藥。未來生物技術(shù)在脫毒這方面會(huì)得到更廣泛的關(guān)注。
總結(jié)
第一，抗氧化劑含量并不一定等于質(zhì)量，關(guān)鍵是看抗氧化劑效果的評(píng)估，好的抗氧化劑的效果才有好的質(zhì)量。
抗氧化劑說穿了是自己犧牲了，保護(hù)了別人(底物)。在純氧的條件下，如果抗氧化能力越強(qiáng)，氧的濃度不會(huì)變化。一旦抗氧化劑消化掉了以后，氧開始對(duì)底物進(jìn)行氧化，氧的分壓迅速下降。不同的抗氧化劑加到一個(gè)飼料里面或者同一個(gè)脂肪里面，表現(xiàn)的效果是不一樣的，有的線平衡達(dá)到幾十個(gè)小時(shí)，我們最長測過能達(dá)到30幾個(gè)小時(shí)。比較差能達(dá)到一個(gè)小時(shí)，半個(gè)小時(shí)，最差的加了抗氧化劑以后比對(duì)照組還要差，這個(gè)抗氧化劑就沒有任何意義了，反而起到反作用。這個(gè)時(shí)候我們就研究出了不同的抗氧化劑拐點(diǎn)的時(shí)間。面對(duì)眾多抗氧化劑的品牌，我們?cè)趺磥磉x擇，怎么樣能保證飼料不被氧化，迫使我的成本做到最低，我們現(xiàn)在就是采用這樣一個(gè)評(píng)價(jià)的方式來選擇抗氧化劑的品牌和添加量。
現(xiàn)在抗氧化劑不是單一的，把不同的成分進(jìn)行配伍，結(jié)果不同;相同的成份，不同的含量，結(jié)果也不同�，F(xiàn)在很多大企業(yè)也在追求平衡點(diǎn)越長，但是帶來了新問題。因?yàn)樵谥袊暳闲袠I(yè)合法的抗氧化劑只有這幾種，實(shí)際上其他行業(yè)也用抗氧化劑，比如說汽車的輪胎橡膠高溫高熱，橡膠很容易被氧化，所以輪胎橡膠中有很多的抗氧化劑，這些抗氧化劑是不能食用的。追求抗氧化劑的效果帶來的新的問題，就是有一些抗氧化劑的廠家開始用輪胎橡膠用的抗氧化劑，例如使用2246，這個(gè)時(shí)候就帶來新的問題--要怎么樣防止出現(xiàn)食品安全的問題。
The English version
Industry know mycotoxin problem is China's feed ingredients, feed ingredients, and even the whole world or is one of the biggest problems we met in the process of breeding. About the elimination of mycotoxin, mycotoxins adsorbent is a better method and adsorbent price from a few dollars to several dozens yuan, even hundreds of yuan per kilogram, price difference is so big, in the farming can have the effect that is how much? Here today, I share some simple mycotoxins adsorbent evaluation methods, as well as the additive, fungicide, and so on.
The evaluation of mycotoxins adsorbent
In the Chinese ministry of agriculture of three directories is no mycotoxins adsorbent this clause, the United States also have no, Europe also have no, also does not have the word in the feed industry terms, the word is used only for commercial and academic discussion. Mycotoxins adsorbent on the official has not accepted, the biggest problem is that many enterprises to the ministry of agriculture feed to reaction, said he was in accordance with the mycotoxins adsorbent factory inspection and the suggestion, add the mycotoxins adsorbent, feed is the official selectiving examination, test result is unqualified, the manufacturer of the adsorbent to went to the department of agriculture. The agriculture department specially made explanation to this aspect, because of the adsorbent in the department of agriculture has not been approved, this is the first question.
Second, about the effect of adsorbent, is very popular, mixed reviews. Its evaluation methods have two types of in vivo and in vitro, in vivo evaluation methods is difficult to say clearly to the method of in vitro, all sell mycotoxins adsorbent manufacturers to feed company do propaganda can give very good data, but a scientific approach must be to prove how the mycotoxin feed raw material is transferred, it should be clear, can be confirmed that this evaluation method is effective.
Method is widely adopted by adsorbent manufacturers now is this: basically the mycotoxin sample free, join the buffer solution, and poison adsorbent, through vibration, centrifugal, separation, take the supernatant. I think this data is the biggest benefit of the operation is simple, but it out of the actual situation, because in the process of our feed mycotoxins, or does not exists in the free state of feed ingredients, or free existence is just part of also by combining state is a part of the, if the assessment is to add a sample free of toxins, such data and actual is far.
Some manufacturers have also seen the problem of the previous method, the second method was improved, called blank matrix method. Take a blank substrate, such as corn or starch, it is do not contain any poison, combined with standard sample, actually added some interference, then add them into the buffer thick liquid, after oscillation, centrifugal, also note that reduce toxin in the supernatant fluid is the amount of adsorption. This time we think it is not the same as real raw material situation or, although increased the interference factors, but the data is not very reliable.
A new method for
Base manufacturers to provide us with method now is such, ourselves through these years of groping formed another method, we think the toxins with raw material is adsorption or the binding force, adsorbent must put toxins with the adhesion strength of the raw material of protein or starch eroded, form a kind of combination, this combination in intestinal juice or gastric juice is not parsed, by this way, we'll do a known toxin content of natural substrate, and then combined with adsorbent, by the method of bionic digestive let toxins and adsorbent to form a combination, after separation. Innovation points, this method is the mycotoxins adsorbent added later, can put the toxins can separate, separate the adsorbent in, can clear mycotoxin where to move from the raw material. We almost spent one and a half years to separation method, finally overcome the separation of the difficulty. But now it seems that the recovery rate of adsorbent can achieve 75%, also is not very ideal, remains to be further improved. I think such a toxin transfer process, to make it clear.
In this way, we look at its adsorption of mycotoxin. Select a aflatoxin contamination of cotton pulp, when the gap is measured data, and then add montmorillonite, carries on the in vitro digestion, to separate cotton pulp and montmorillonite, the separated montmorillonite can reach about 80 PPB. After separation, aflatoxin and transferring them to the separation of the adsorbent. Then look at the cattle feed, front is added according to the 5 kg per ton, now there is a way to add, is according to 0.1 kg, 0.3 kg, 1 kg, 3 kg, 5 kg, 7.5 kg, 10 kg, per tonne of feed that according to the proportion of added, without adding former cattle feed is 54 PPB, at the time of adding different proportion, the cattle feed after separation, toxin content decreased obviously, add to 5 kg to 7.5 kg, adsorption data is lower up, are generally in 5 kg, it is a better adsorption.
Different manufacturers of the adsorbent, to aflatoxin, to vomiting toxins, gibberellic ketene, the end result is different, including montmorillonite, adsorption of aflatoxin is more effective, good can do around 70, adsorption of vomiting toxins with gibberellic ketene, according to we make to the effect of this method is very limited, is vomiting toxins good manufacturer can do 25 or so, gibberellic ketene do 20 or so.
The choice of mycotoxins adsorbent
Through these data we can see some? The first is the questions about the toxin adsorbent, although officials have not recognized, but the commercialization of only you can do it, not the other. But there is no accepted standard, evaluation method is directly with the prototype, the buffer is better adsorption effect, the data is also very beautiful, but the data is exaggerated, in fact both farmed enterprise, or feed enterprises, we see the same in the production practice, the vomiting toxins, eliminate to gibberellic ketene, no matter use what kind of method, are very limited in practice. Through the experiments we get the conclusion is that the common mycotoxins, if adopt the method of adsorbent, the aspergillus flavus toxin is effective. This effectively I need to spend how many money can do? Three of the five dollars montmorillonite is enough, don't need the money a few dollars to achieve such effect. If you want to gibberellic ketene and vomiting toxins effectively reduce, now by the method of adsorption is impossible, is very limited, at best, that is, to reduce the 20 to 30, if you want to reduce the only way is to buy good medicine. The future biotechnology in detoxification will get wider attention.
conclusion
First, antioxidant content does not necessarily equal to the quality, the key is to see the antioxidant effect of evaluation, good antioxidant effect is good quality.
Antioxidants, after is his sacrifice, to protect others (substrate). Under the condition of pure oxygen, if the stronger antioxidant ability, concentration of oxygen will not change. Once the digest antioxidants, oxygen began oxidation on the substrate, the oxygen partial pressure drops rapidly. Different antioxidant added to a feed or inside the same fat, the effect of the performance is different, some line balance is a few hours, we tested longest can reach 30 hours. Less able to achieve an hour, half an hour, after the worst added antioxidant is even poorer than the control group, the antioxidant doesn't make any sense, but counterproductive. This time we developed different antioxidant inflection point of time. In the face of numerous brands of antioxidants, we how to choose, how to keep the feed from oxidation, forcing me to achieve the lowest cost, we have now is the way of adopting such a evaluation to select antioxidant brand and add quantity.
Antioxidants are not single now, put the compatibility of different ingredients, different results; The same ingredients, different levels, different results. Now many large enterprises in the pursuit of the longer the balance, but has brought new problems. Because in China feed industry legal there's only several antioxidants, in fact other industries with antioxidants, such as car tyre rubber in high temperature high fever, the rubber is easy to oxidation, so there are many antioxidants in tire and rubber, these antioxidants are inedible. Achieve the effect of antioxidant brought new problems, is some antioxidant manufacturers began in tire and rubber in antioxidants, such as using 2246, this time will bring new problems, how to prevent food safety problems.
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