In recent years, a number of problems in the Chinese farming industry have been attributed to the presence of mycotoxins in feed: an increasing occurrence of gizzard lesions during warm and hot seasons; reproductive failures in ruminant and swine herds; food safety incidents due to toxic concentrations of aflatoxins in milk; and, in general, farming animals that showed low immunity, poor performance and slow growth.
The purpose of this blog is to capture our vision about the use of mycotoxin binders in China and to redress some of the misconceptions that we often encounter during our field visits to customers. In this way, we intend to help to achieve a healthier and more efficient farming.
Risks posed by mycotoxins
Mycotoxins are chemical weapons used by fungi against bacteria in their struggle to ferment organic matter. They accumulate along the feed production chain from the field to the farm through harvest, grain storage, transportation and feed manufacturing and storage.
Due to their physicochemical properties (thermo resistance, poor solubility in water, high stability, slow decomposition), it is extremely difficult to eliminate the mycotoxins from feedstuffs.
Relationship between mycotoxin contamination and climate
Mycotoxin contamination is a global problem, as mycotoxigenic molds are able to grow in a wide range of environmental conditions. Temperature and humidity are the main factors determining the specie of mold and type mycotoxin that will contaminate a feedstuff. Thus, generally speaking, we can say that the most frequent contamination that will be found in each climate type is as follows:
- Hot and wet climates: aflatoxins, Ochratoxin, fumonisins.
- Hot and dry climates: aflatoxins, zearalenone, ochratoxin.
- Cold climates: thricothecenes, fumonisins, zearalenone.
In China, many farmers believe they only need to worry about mycotoxin risk during the warm season. It is true that high temperatures facilitate the growth of certain fungi, but as mentioned above, mycotoxins enter the feed production chain at steps: During cold seasons, feed may contain mycotoxins formed during growth of the cereal in the field and during harvest, in the previous Summer. Moreover, there are fungi that are able to grow at low temperatures; in fact, the genus Fusarium sp. is able to proliferate and secrete mycotoxins (trichothecenes, fumonisins, zearalenone) at temperatures as low as 10ºC.
Relationship between mycotoxin contamination and regional economic development
During our field visits, we observed that often there is a relationship between the level of economical development of the area where the farm is located and the level of mycotoxin contamination in feed. Usually, the areas with worse economical development show more risk factors, such as:
- Poor temperature and moisture control of storage silos and bins.
- Deficient risk assessment of mycotoxin contamination in feedstuffs.
- Lack of mycotoxin control programs.
Consequences of mycotoxin contamination
According to Pittet, 1998, 42% of the feedstuffs worldwide are contaminated with either aflatoxins, zearalenone, vomitoxin, fumonisins or ochratoxin.
Mycotoxins can cause two kinds of problems in the farms:
- Clinical diseases, that is, visible problems that can be observed in alive animals or during necropsy. In China, one of the most widespread lesion in poultry is gizzard erosion by trichothecenes. It can be found very frequently, especially during warm seasons.
- Subclinical problems, such as impairment of feed intake, growth and productivity; immunodeficiency; ialterations of the reproductive cycle, etc. Reduction of feed use is one of the most worrisome consequences of mycotoxin poisoning. Mycotoxins can reduce up to 13% of the nutritional value of complete feed (Han et al, 2008). On the other hand, reduction of feed intake and impaired growth by the presence of trichothecenes is one common problem in the Chinese swine industry.
Mycotoxin binders in the Chinese market
Research on mycotoxin binders started in the late 80’s, when Dr. Taylor and Dr. Phillips investigated the application of an hydrated sodium calcium aluminum silicate as a binder for aflatoxins. In the following years, a remarkable number of commercial binders appeared, especially in Europe and USA.
Mycotoxin binders appeared in China during the 90’s, but the acceptance of this kind of product by farmers and nutritionists did not follow until many years later. Still in the early 2000’s, there were frequent problems related to heavy mycotoxin contamination that caused numerous problems in the farms.
In recent times, farmers and nutritionists have become more aware of the risks of mycotoxin contamination and of the importance of mycotoxin binders. Over the past decade, the demand of mycotoxin binders is growing and a number of local and foreign brands of binders entered the Chinese market.
Because accessing the market is relatively easy, nowadays there are more than 200 brands of mycotoxin binders in the Chinese market, including well-known domestic and foreign brands and less-known products.
In 2011, feed production in China reached 168 million tons, while the same year the size of the binder market was more than 410 million RMB. The market share of imported brands reached 50%.
Classification of mycotoxin detoxifying agents
According to the mechanism of action and to the nature of the additive, we can classify the mycotoxin detoxifying agents in the following categories:
1. Mycotoxin-adsorbing agents or mycotoxin binders: large molecular weight compounds that are able to bind the mycotoxins inside the gastrointestinal tract of the animal. In this way mycotoxins pass through the animal and are eliminated via the faeces, avoiding their harmful effects.
1.1. Raw clays: High adsorption rate for aflatoxins but the binding ability for other mycotoxins is very variable. Dose is high and therefore they can bind nutrients and pharmaceuticals. Cheap. In China, they are popular amongst budget-limited customer. Producers often face complains for product failures.
1.2. Treated aluminosilicates: raw clays that have been treated chemically or physically in order to enhance their binding capacity. Treated aluminosilicates are the most popular compounds in the market, because they are cost-effective and dose is relatively low. Their binding capacity is usually high for aflatoxins, while for other mycotoxins is very variable. Many local and foreign brands use treated aluminosilicates as their main active ingredient.
1.3. Yeast cell walls: yeast cell walls consist almost entirely of proteins and carbohydrates (glucose, mannose, and N-acetyglucosamine). Adsorption of aflatoxins is poorer than the above mentioned compounds; binding of difficult to bind mycotoxins varies greatly among products but it is usually higher than raw clays. Products based on yeast cell walls are normally expensive.
2. Mycotoxin-biotransforming agents: Bacteria, yeasts, fungi, and enzymes that are able to degrade the toxin into a non-toxic compound. These products are usually very effective, but only target one or a few mycotoxins so need to be included in the feed together with a binder. Expensive.
Legal guaranteed binding rates of top sales brands
As a result of the irruption on the market of many products that claim to be mycotoxin binders, countries like China, Brazil or the European Union demand that the product is subjected to a series of tests (in vitro, in vivo, or both) in order to demonstrate its effectiveness. The objective of this policy is to help the user to choose a good product and not have to rely on the marketing information provided by the manufacturers.
Currently, Chinese regulation requires demonstrating the effectiveness of mycotoxin binders by in vitro binding tests. In the table below, we show the legally guaranteed mycotoxin binding rates of some of the products with highest market share in China.
Common misconceptions about mycotoxins and mycotoxin binders among Chinese users
A survey made in 2011 by Nick Yong (eFL Research) among Chinese nutritionists and feed additive purchasers showed that only 60% of the respondents believed that mycotoxin binders are essential feed additives; 30% believed that it binders were useful but not indispensable; 10% were not using adsorbents and thought that they were not necessary. More than 80% of the respondents declared to be aware of the risks of mycotoxins.
In the recent years, farmers and nutritionists are more knowledgeable about the hazards and of the consequences of mycotoxin contamination. Users also have more information on the different types of mycotoxin-detoxifying agents and how to apply them in practical situations. However, there are still some widespread misconceptions that need clarification:
Misconception nº 1
Some feed manufacturers and farmers think that adding a mycotoxin binder to feed is not indispensable, that the improvements by binders cannot clearly be seen in the farm and, as a consequence, that binders constitute a cost that they should better save.
Independent research works are providing increasing proofs on the negative effects of mycotoxin in farm animals. Recently, scientists have concentrated on the “invisible” effects of mycotoxins, especially those related with the animals being more susceptible to diseases and those connected to impaired productivity. Unless mycotoxin levels are very high, there are not clear signs of mycotoxicosis. Often, the main consequence of mycotoxin contamination is the loss of productivity, that may be mistakenly attributed to other causes, while specific lesions are only found sporadically. Therefore, even if there are not visible pathological signs, feeding contaminated feed without using an anti-mycotoxin agent, results in losses that are far more expensive than adding a mycotoxin binder to feed.
Misconception nº 2
Many consumers think that mycotoxin contamination can be judged by the appearance of the grain.
White it is true that the presence of molds, broken grains or dust is a clear warning of possible mycotoxin contamination, there are circumstances when mycotoxins could be present in grain, without any visible mold. For example, treatment with propionic acid can remove the mold but leave the mycotoxins behind because mycotoxins are extremely stable chemical compounds. Mycotoxin determination by ELISA, GC or other methods is necessary to be able to be aware of the real contamination of the feedstuff.
Moreover, an experienced technician is required to assess the real risk, by studying the results of the analysis. A sample often contains more than one type of mycotoxin and the toxicity of combinations of toxins cannot always be predicted based upon individual toxicities. Interactions between concomitantly occurring mycotoxins can be antagonistic, additive or synergistic.
On the other hand, there are some factors contributing to changes in the contamination pattern of raw materials: the use of cheaper, more contaminated feedstuffs, such as DDGS; global warming, that is forecasted to result in the emergence of new strains of fungi with (possibly) new classes of mycotoxins with novel characteristics.
For all the reasons mentioned before, it is necessary to routinely control the levels of mycotoxins in feedstuffs; assess the actual risk of mycotoxicosis and set up HACCP plans to reduce hazards.
Spring and summer are the only risky seasons for mycotoxin contamination. There is no real need to use mycotoxin binders during autumn and winter.
Molds can grow and mycotoxins can be produced either pre-harvest or post-harvest, during storage, transport, processing, or feeding. Because crops can already be contaminated while they are in the field, and feed producers often have authority control over crop conditions, control of additional mold growth and mycotoxin formation is highly dependent on storage management. After harvest, temperature, moisture content, and presence of insects or birds are the major factors influencing mycotoxin formation. Generally speaking, molds grow over a temperature range of 10-40°C, but there are some species that are able to grow at -5ºC. In example, some Fusarium species have been reported to grow prolifically at 25 to 30°C without producing much mycotoxin, but at near-freezing temperatures, large quantities of mycotoxins are produced with minimal mold growth.
Therefore, when in winter we are feeding the animals the grains harvested during the previous summer or autumn, if weather during harvest was wet or if storage conditions are not optimal, molds grow and mycotoxins formation continues. The addition of mycotoxin binders is necessary all year long.
Animals with a short life, such as broilers, are not much sensitive to mycotoxins, especially during grower and finisher stages.
This view is a complete mistake. All farm species are sensitive to certain mycotoxins. In the case of broilers, it is suggested that even mildly contaminated feed can reduce daily growth 2-3 grams/day. In conclusion, mycotoxin binders are necessary to prevent diseases and productivity losses in all species and ages.
How to choose the right mycotoxin detoxifying agent?
Having such a variety of products on the market, how can the user choose the most suitable one?
The good news is that, as mentioned before, some countries such EU, Brazil or China ask the producers to demonstrate the effectiveness of their products before they are able to be registered and sold as mycotoxin binders.
Currently, Chinese regulation requires demonstrating the binding capacity by in vitro binding tests. Therefore, the legally guaranteed adsorption rates are one very useful tool to choose a mycotoxin binder.
Within the whole Chinese market, PlusBind© and PlusBind Bio© are the products that guarantee the highest adsorption of zearalenone, more than 82%. The result was confirmed during the registration and verification of the two products in the Feed Quality Supervision and Testing Center of Jinan, belonging to the Ministry of Agriculture of China. Regarding aflatoxins, PlusBind© and PlusBind Bio© guarantee a binding rate more than 96%, higher than many famous brands.
If you are like our customers, increasingly worried by mycotoxins, maybe you are would like to know what can we do for you?
We are experts.
- Our technical team can help you build HACCP program to avoid contaminated feedstuff arriving into your feed production system.
- Our lab specialists can help you to analyze your feed and evaluate the results.
- We have excellent mycotoxin binders, with the highest binding rate in the Chinese market and a low dose.
Products of Choice
PlusBind® with its expanding structure and its high binding efficiency per gram of product, is the ideal solution to maintain health and productivity in despite of defective cereal conditions.
PlusBind Bio® is a highly effective mycotoxins binder with prebiotic effect, which will restore balance of digestive flora and promote the growth of Lactobacillus species. Lactobacillus species have been proven to exert a detoxifying activity on mycotoxins.
Qi BaoHuai, Product manager, email@example.com
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