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我們在選擇霉菌毒素脫毒劑類產(chǎn)品（下稱脫毒劑）時往往面臨一個問題的困擾，即是如何正確評估此類產(chǎn)品，然而目前國內(nèi)尚無對應(yīng)的國家標(biāo)準(zhǔn)或者行業(yè)標(biāo)準(zhǔn)，各品牌產(chǎn)品所執(zhí)行的均是自己的企業(yè)標(biāo)準(zhǔn)，于是各種方法理論目不暇接。本節(jié)對不同評估方法的可行性、準(zhǔn)確性略作梳理。
脫毒劑的了解與評估，按手段可分為資料了解、實驗室評估和動物試驗評估，其中實驗室評估又有體外方法、模擬體內(nèi)（仿生）方法等；按評估目的可分為有效性評估、安全性評估、穩(wěn)定性評估等等，以下就實驗室評估和動物試驗評估加以分析。
1、實驗室評估
正確有效的實驗室評估方法可以幫助我們快速分析、認(rèn)知某個添加劑產(chǎn)品，繼而協(xié)助或指導(dǎo)動物試驗的后續(xù)進(jìn)行，實驗室評估快捷，沒有動物試驗?zāi)菢映杀靖�，工作量大的缺點。實驗室評估方法，無論是體外吸附分析或者是仿消化道環(huán)境的吸附分析，均是旨在創(chuàng)造一種毒素與脫毒劑相反應(yīng)的環(huán)境，反應(yīng)后再通過不同檢測器進(jìn)行量化分析，以此來判斷和證明一種脫毒劑對某種毒素具備多少處理能力。理論上，如果一種物質(zhì)在體外不能良好處理某種毒素，那么很可能在體內(nèi)也是如此，如果想評價不同品牌產(chǎn)品的效果，實驗室吸附評估方法作為首當(dāng)其沖的方法還是很有意義的。如Diaz在緩沖液體系下比較多種脫毒劑劑結(jié)合AFB1的效果（2002）；如Sabater- Vilar模擬消化道環(huán)境比較常見脫毒劑對DON和ZEN 的處理能力（2007），實驗室方法能直觀評價吸附劑對霉菌毒素的吸附性能，作為一個評價手段，應(yīng)該能起到篩選區(qū)分脫毒劑的效果。然而，實驗室評估方法不是一成不變的吸附分析方法，進(jìn)行實驗室評估時需要考慮更多因素。舉兩個例子：一、現(xiàn)有的脫毒劑處理毒素的理論機(jī)理有很多，有物理吸附的，有化學(xué)結(jié)合的，有生物降解的；有效成分也不一，有非金屬粘土礦物的、有微生物的、有酶制劑的、有植物多糖或真菌多糖成分的，不一而足。因此，不可能用實驗室吸附試驗去評估一個宣傳以微生物或酶解毒素為機(jī)理的脫毒劑，也不可能用粗灰分多少去評判一個無機(jī)或有機(jī)脫毒劑的優(yōu)劣。二、霉菌毒素的在谷物里的存在形式不是一成不變的，有各種結(jié)合態(tài)，在動物體內(nèi)也因不同代謝階段而呈不同衍生物和異構(gòu)體，這使得實驗室評估方法的針對性和準(zhǔn)確性都會有偏差甚至偏離。比如霉菌毒素可以是純單體游離，可以是與基質(zhì)組成復(fù)合物，物理可溶或被束縛(如伏馬毒素與淀粉分子，赭曲霉毒素嘔吐毒素與寡聚糖分子結(jié)合)，可以是與植物或真菌結(jié)合的DON-3-葡萄糖苷和赤霉烯酮-14-硫酸鹽。
2、動物實驗評估
按照官方對飼料添加劑的評估方法要求，動物實驗評估是必不可少的一個環(huán)節(jié)。以評估脫毒劑有效性試驗為例，飼養(yǎng)實驗分組至少5個組別，分別是正負(fù)對照組和3個梯度的處理組。如（1）正對照組，不含霉菌毒素和吸附劑；（2）負(fù)對照組：含有霉菌毒素的日糧；（3）至（5）：含有不同濃度脫毒劑的霉變?nèi)占Z。同時要求每個組別設(shè)定6個重復(fù)以上�？梢娒摱緞﹦游镌囼炘u估是一項成本大、工作量大的工作。
脫毒劑的動物試驗評估，可分為短期有效性評估和長期有效性評估。短期有效性評估可通過觀察和測量某指標(biāo)、某外觀狀況以判斷該脫毒劑是否具有處理毒素的效果，如短期控制牛乳中黃曲霉毒素M1殘留、短期控制青年母豬的假發(fā)情問題。而長期有效性試驗，除了考量增重、采食量、死亡率、飼料效率等必備指標(biāo)外，還可以通過測定動物的其他生理生化指標(biāo)來說明脫毒劑對霉菌毒素的處理程度，如測定不同處理組的血液常規(guī)指標(biāo)，包括血清總蛋白、白蛋白、球蛋白、膽固醇等；或其他生化免疫指標(biāo)如谷草轉(zhuǎn)氨酶、谷丙轉(zhuǎn)氨酶和谷胱甘肽硫轉(zhuǎn)移酶等；或者測定母畜的E2、LH等內(nèi)分泌指標(biāo)；進(jìn)一步深入研究的話，可以評估血液或某組織中毒素的含量以及排泄物中毒素含量，以評估使用脫毒劑后毒素的去向。在脫毒劑對霉菌毒素的有良好處理效果的前提下，那么這些生理生化指標(biāo)也不會因一定量毒素的出現(xiàn)而帶來波動。
3、其他評估內(nèi)容
對于脫毒劑的其他評估內(nèi)容，主要就是安全性和其他破壞性問題，如絕大多數(shù)的非金屬粘土礦物的非選擇性吸附特性，是否對飼料中的微量營養(yǎng)物質(zhì)產(chǎn)生干擾，或者是否給飼料帶來重金屬污染等降低飼料品質(zhì)和安全性的危害。這就要求在評估脫毒劑有效性的同時要考量其對一些維生素、藥物、微量元素的吸附干擾作用、以及其砷、鉛、氟、二噁英含量是否達(dá)到危害飼料安全的程度。.
The English version
We take off our agents in choosing a mycotoxin products (hereinafter referred to as stripping agents) often face a problem, that is, how to correctly evaluate this kind of product, however, the current domestic, there is no corresponding national standards or industry standards, each brand products which are performed by their own enterprise standards, and the ways of theory. This section of the different assessment method is feasible, accurate guarded.
To take off the poison of understanding and evaluation, according to the method can be divided into information, laboratory evaluation and assessment of animal testing, including laboratory evaluation and the in vitro method, simulated the body (bionic), etc.; According to the evaluation purpose can be divided into the effectiveness evaluation, safety assessment, stability evaluation and so on, the following laboratory evaluation and assessment of animal testing analysis.
1, laboratory evaluation
Correct effective laboratory evaluation method can help us to quick analysis, cognitive an additive products, and then to assist and guide the follow-up of animal testing, laboratory evaluation and fast, no animal test that the high cost, workload big shortcoming. Laboratory evaluation method, either in vitro adsorption or adsorption is the imitation of the digestive tract environment analysis, are designed to create a kind of poison with poison off the opposite should be environment, reaction after a quantitative analysis by different detector, to judge and prove a poison off for some toxins have how much processing power. Good in theory, if a substance in vitro can't deal with some kind of poison, so it is likely in the body, if you want to evaluate the effect of different brand products, laboratory evaluation methods as a way to bear the brunt of adsorption is very meaningful. Such as Diaz in the buffer system comparing a variety of agents remover in combination with the effects of AFB1 (2002); Such as Sabater - Vilar simulated gastrointestinal environment is common to take off the poison of the processing capacity of DON and ZEN (2007), the laboratory method can directly evaluate adsorbent for the adsorption performance of mycotoxin, as a means of evaluation, should be able to play a screening to distinguish the effect of the poison. However, laboratory evaluation method is not static adsorption method, need to consider more factors in laboratory assessment. Two examples: first, the existing agents to deal with the theoretical mechanism of toxin has a lot of, have physical adsorption, chemical combination, biodegradable; Effective components also differ, non-metallic clay mineral, microbes, enzymes, plant polysaccharides or fungi polysaccharide composition, and so on. Adsorption, therefore, can not use laboratory test to evaluate a publicity for microorganism or enzyme toxins mechanism of poison, also can not use coarse ash how to judge the pros and cons of an inorganic or organic agents. Second, the existence of mycotoxins in grain form is not static, with all kinds of combination state, in animals also are different due to different metabolic phase derivatives and isomer, this makes the pertinence and accuracy of the laboratory evaluation method will have a deviation even deviation. Mold toxins can be pure monomer free, for example, can be a complex with the substrate composition, physical or soluble bound (such as v toxins and starch molecules, ochre and aspergillus toxin vomiting toxins and widowhood chitosan molecules), can be combined with plant or fungi DON - 3 - glucoside and gibberellic ketene - 14 - sulfate.
2, animal experiment evaluation
In accordance with the requirements for the official evaluation methods for feed additives, animal experiment evaluation is one of the essential link. To assess the efficacy of poison off test, for example, raising the experimental group at least five categories, respectively is the processing of positive and negative control group and three gradient group. Such as (1) is the control group, excluding mycotoxin and adsorbent; (2) the negative control group: the diet containing mycotoxins. (3) to (5) : mildew diet containing different concentrations to take off the poison. At the same time requires each group set 6 repeat. Visible to take off the agent evaluation of animal testing is a big cost and volume of work.
Take off poison animal tests and evaluation, can be divided into short-term effectiveness assessment and long-term effectiveness assessment. Short-term effectiveness evaluation by observation and measurement of a certain index, the exterior conditions to determine whether this to take off the poison has to deal with the effect of the toxin, such as short-term control of aflatoxin M1 residue in milk, short-term control of the gilt off heat problem. Effectiveness and long-term test, weight gain, feed intake, in addition to the considerations, proper index, mortality rate, feed efficiency, can also by measuring the other animal physiological and biochemical indexes to show off agent handling of mycotoxin, blood routine indexes such as the determination of different treatment group, including serum total protein, albumin, globulin, cholesterol, etc.; Or other biological immune indexes such as aspertate aminotransferase, alanine aminotransferase and glutathione s transferase, etc.; Or determine the E2, LH female endocrine indexes such as; Further in-depth study, you can evaluate the content of toxins from the blood or tissue and toxin content in the waste, and to assess the use of poison off the toxin. In to take off the poison of mycotoxins has good treatment effect under the premise of these physiological and biochemical indicators will not bring fluctuations due to the presence of the amount of toxin.
3, other evaluation content3
For take off poison other assessment content, security and other destructive is main problem, such as the vast majority of non-metallic non selective adsorption characteristics of clay minerals, whether to feed the micronutrients to produce interference, or bring to feed the harm of heavy metal pollution reducing feed quality and safety. This request in the evaluation of effectiveness to take off the poison for some vitamins, medicines, and at the same time to consider the adsorption and interference effect of trace elements, and its arsenic, lead, fluoride, dioxin levels if the degree which endanger the safety of the feed. .
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