The presence of mycotoxins in your pig herd’s feed regimen may result in unintended consequences. These toxic substances, produced by the fungi in feedstuffs, not only have the power to negatively influence growth and performance but can also suppress long-term reproductive performance. These symptoms are not the only issues that producers may see manifest in their animals as a result of a mycotoxin problem; feed refusals, swollen vulvas in gilts and sows, and the reduced effectiveness of treatments and vaccines can also become a threat to any operation.

The Alltech 2022 U.S. Harvest Analysis is an extensive analysis of the mycotoxin risk across the country, as assessed by Alltech’s in-house mycotoxin expert, Dr. Max Hawkins. This report utilizes samples collected from throughout the country that have been analyzed through Alltech’s trusted 37+® mycotoxin analysis.

Outlined below are the key takeaways from the 2022 U.S. Harvest Analysis, as well as several proactive tips that can help pig producers mitigate their mycotoxin risk.

Here are five insights into the mycotoxin risk for the 2022 corn crop:

1. Responses to changing weather conditions

The 2022 growing season brought with it a 180-degree difference in the challenges producers faced in various regions. Drought conditions in the midwestern United States had a significant impact on corn health and yield across the western corn belt. More severe drought conditions were detected by the drought monitor in the West, and these conditions extended eastward into Illinois, Indiana and part of Ohio. Rains in late July and August eased the drought conditions east of the Mississippi River, but this rainfall — on top of already-drought-stressed corn — spurred the growth of Fusarium molds, producing a variety of type-B trichothecenes, fumonisin and zearalenone.

2. Average mycotoxin samples found

• 119 samples had an average of 6.7 mycotoxins per sample
• 98% of the samples contained two or more mycotoxins
• All samples contained between one and 12 mycotoxins each

Fusarium-produced mycotoxins were the most frequently occurring due to their preference for moist environments and moderate temperatures. The mycotoxins found most commonly in the samples included:

• Emerging mycotoxins (97.48%)
• Fusaric acid (83%)
• Type-B trichothecenes (68%)
• Fumonisin (65%)
• Zearalenone (35%)

3. Areas of greatest risk

The mycotoxins produced by molds that represented the greatest risk were type-B trichothecenes, also known as the DON family, and zearalenone. Type-B trichothecenes can negatively impact feed intake, digestion, average daily gains, feed efficiency, gut wall integrity, liver function and immune system responses. Zearalenone can act synergistically with DON to magnify the risks for reproduction, the number of pigs born, the return to estrus and conception rates. Even when the presence of these mycotoxins is lowered by the corn inclusion rate, they still represent a high risk in the finished feed.

4. Geographical location and storage differences

When it comes to Fusarium mycotoxins, the risk level tends to increase as we move from West to East. However, one factor that could increase the risk in the West is storage. Corn needs to be dried to a moisture level of 14% or less to be safely stored for extended periods of time. Across the Midwest, winter weather led to periods of cold temperatures, but in general, temperatures were above what is generally considered normal. These warmer temperatures — along with grain that was inadequately dried or left exposed to moisture — increase the likelihood of mold production and, as a result, mycotoxin growth.

5. Impact on the swine industry

The 2022 corn crop does have ranging levels of risk depending on the location of the pigs and production settings nationwide. Differing storage types could provide an environment in which the risk at harvest could increase over time. This necessitates the need for the corn to be analyzed to determine its mycotoxin levels and risk as we move through the winter and spring of 2023.

Proactive tips to help pig producers mitigate their mycotoxin risk

Make sure your feed mill is checked often.

When it comes to mycotoxins in pig feed, conducting proper testing allows for any potential risks to be managed. Dr. Hawkins shared that utilizing a mycotoxin testing program that is based on an instrument — such as HPLC MS/MS — will provide you with the most accurate and comprehensive analysis available.

Furthermore, starting the analysis of your raw materials as close to harvest as possible will ensure that you have enough time to develop an all-encompassing risk management and mitigation plan. If this analysis is properly scheduled, then your operation will have a good understanding of the risk posed by the feedstuffs being provided to your pigs prior to the animals actually receiving it.

“After utilizing comprehensive testing at harvest, you may then set up a quick analysis that can be used at your farm or mill,” said Dr. Hawkins in the U.S. Harvest Analysis webinar. “We would also suggest that you do more testing at various times throughout the year to ensure that your quick-test protocol for your grain or pig feed is still a solid plan for the production system.”

Keep feed bins dry.

Make sure your feed bins are closed and that there are no potential points of entry where moisture could get into the feedstuffs at the top of the silos.

In the summer months, feed tanks or feed bins can get very hot and are prone to sweating. Ensure that feed gets moving through the tanks or bins quickly. If there is feed leftover, transfer it to another barn.

Pay attention to feed intake.

Pigs are especially sensitive to DON; it’s like they can sense or smell it. Therefore, they tend not to eat contaminated feed. Abstaining from eating can be a classic sign that mycotoxins are present.

Instituting a proper mycotoxin management strategy will help reduce the risk of low performance in your herd. With a plan in place for mitigating mycotoxins on your operation, the chances that your pig herd will perform well in 2023 increase exponentially. 

If we learned anything from 2020, it is that we cannot control everything. For instance, we can’t control the weather, but we can work to control the mycotoxin risk it presents. Weather is the main influencing factor when it comes to mycotoxin risk, leading to a variation in risk levels across the U.S. This year is no exception to that trend, with mycotoxin levels having a wide distribution in the U.S. corn harvest. Mycotoxins can be responsible for the loss of production and efficiency in our animals — a duo we are not interested in.

What are mycotoxins?

Molds and fungi on crops naturally produce mycotoxins. Mycotoxins are ever-present on-farm but can vary in severity based on feed sources, storage and growing conditions. The three most common types of mycotoxins include Aspergillus, Fusarium and Penicillium. Aspergillus is responsible for aflatoxin B1, which can be more abundant with increased drought stress and dry field conditions. Trichothecenes and zearalenone are related to Fusarium. Trichothecenes are common field toxins in grain and silage, and swine are particularly impacted by this mycotoxin because they are considered a more sensitive species to deoxynivalenol (DON). T-2/HT-2 toxins and other trichothecenes are the most toxic for most species, while ochratoxins and citrinin are related to Penicillium. When an animal consumes mycotoxin-contaminated feed, there is risk of reduced production, immune suppression and decreased overall efficiency.

Learn more about mycotoxins at knowmycotoxins.com.

2020 Harvest Analysis

Dr. Max Hawkins, Alltech’s mycotoxin and harvest expert, presented his analysis, giving an insider’s view on this year’s crop, during the 2020 U.S. Harvest Analysis.

Crops are influenced by weather as we go through the growing season, leading to regionalized mycotoxin risk based on weather patterns. The Corn Belt had moderate to severe drought conditions throughout the growing season, in addition to wind-storms, which also affected corn crops. The Eastern U.S. saw above-normal rainfall on heat-stressed and dry crops. It should be noted that while the overall risk is normal this year, where the risk is high, it is notably high. These risks can be manageable if we are able to feed the average, which is why we need to do testing to evaluate what the potential maximum levels are.

Mycotoxin risk breakdown by species:

The 120 corn samples that were analyzed by Alltech 37+ contained an average of 5.9 mycotoxins per sample, with 50% of these samples considered moderate- to high-risk and 50% low-risk. While corn in general is relatively low-risk, pockets of high-risk samples could be an increasing concern with lower corn yields. If we are not able to be as selective when feeding corn, we may get into feeding higher-risk corn, or higher-risk feed ingredients may be used to compensate for less corn in the diet.

• Swine

The mycotoxin risk for sows is moderate to high, specifically related to DON and zearalenone, both of which present risks high enough to impact sow reproduction and performance. Grow-finish pigs are also affected by DON, which can impact gains, gut health and feed efficiency.

• Poultry

Overall, the samples showed a low to moderate mycotoxin risk for poultry, with the risk increasing the farther East the samples came from. Compared to swine, poultry are projected to have a lower risk from DON, but the risk presented by mycotoxins is still high enough to impact gains/feed efficiency and gut health.

• Ruminants

The 273 samples of corn with a high moisture content (HMC) included an average of 6.1 mycotoxins per sample, creating a distribution of 60% low-risk and 40% moderate- to high-risk samples. On average, there is a low risk for beef and cattle; while the presence of mycotoxins has the potential to affect performance, overall, this risk is very manageable. Producers in the East and upper Midwest are projected to have the highest risk due to dry conditions followed by heavy rainfall.

The data from 2020 suggests much more prevalent and higher levels of aflatoxin B1, which should be of particular interest to dairymen. Dairy producers should monitor and test for mycotoxins in corn silage, especially if their operations are located in high-risk areas. Additionally, aflatoxin B1 can convert to aflatoxin M1, which can be excreted in the milk, leading to food safety concerns.

Managing mycotoxins

There will always be mycotoxins in feed, but knowing what they are and what risk level they pose is critical to mycotoxin management. The Alltech 37+ mycotoxin analysis test provides a realistic picture of the mycotoxins in feed ingredients or TMRs. This comprehensive test allows for quick diagnosis, effective remediation and planning for future control measures. To learn more about having a 37+ test completed on your farm, please visit the Alltech 37+ mycotoxin page.

Dr. Hawkins recommends testing each time you change your feed or introduce a new feed ingredient in order to properly measure your mycotoxin risk. Going forward, risk levels can change based on fermentation, and we need to watch out for “storage mycotoxins.” There have been forecasts of a dry spring, but the mycotoxin risk is fluid and always changing.

To watch the complete 2020 U.S. Harvest Analysis, click here.

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The threat of mycotoxins is nothing new to the companion animal industry. However, never before has it been so prevalent and public. Most recently, the reality of mycotoxins in pet food manifested in the death of more than 70 dogs and illness in 80 more in the U.S. due to aflatoxin poisoning. This led to a massive recall of pet food products after they were found to be the source of the issue (FDA, 2021).

Although pet food manufacturers have stringent quality and safety practices in place for choosing ingredients, even with strict testing procedures for mycotoxins in incoming materials and finished pet food, there can be challenges in knowing exactly what might be hiding in seemingly safe ingredients.

Grain processing, sampling error, analytical methods, synergistic interactions and storage conditions can all present challenges to the pet food manufacturer when trying to accurately detect mycotoxins. A disturbing event like this recent aflatoxin poisoning further emphasizes the need for grain and feed producers to know which mycotoxins they are most likely to encounter, what risks those mycotoxins bring to the table and how best to manage them.

What is aflatoxin?

Mycotoxins are substances that are produced by mold or fungus. Aflatoxin, specifically, is a metabolite produced by the greenish-yellow mold Aspergillus flavus (A. flavus) and comes in four different strains: B1, B2, G1 and G2. The most toxic of those, aflatoxin B1, is a carcinogen that can adversely impact liver function and immune response.

Where does aflatoxin appear?

A. flavus can grow in a temperature range of 54–118° F, with optimum growth at 98.6° F. Its moisture requirements are low, meaning just 13–13.2% is optimal for growth.

Aflatoxin is usually seen in corn, cottonseed, peanuts, almonds and their associated byproducts. For this reason, corn is one of the ingredients in dog food that poses the greatest risk to companion animals.

All of these crops are typically grown in the southern U.S., where the temperature and moisture are optimal year after year. However, in 2020, the August 25 Drought Monitor showed that these optimal conditions spread far to the north and east, into corn-growing regions.

A recent report in the results of the Alltech Summer Harvest Survey showed that this change in weather patterns has created an unusual situation in which aflatoxin is being detected at higher than normal levels in corn samples outside of the normal high-risk areas. This now presents a new set of challenges for pet food manufacturers to consider when purchasing ingredients.

A. flavus can infest the corn plant through the silks at pollination, affecting the grain, and via stalks and leaves damaged by insects and weather events, such as high winds and hail. Infestation can be field-wide but is more often pocketed in areas of greater plant stress. This can make it challenging to identify aflatoxin in corn grain, as it may only be present in a few kernels in a truckload. Therefore, when testing incoming ingredients for mycotoxins, multiple pooled samples are required to accurately identify the potential risk.

Stored corn needs to be dried to less than 14% moisture and closely monitored for mold growth and insect damage. Screening the grain going into and/or out of storage is a good practice to remove the damaged and cracked kernels that can be a primary source of not only aflatoxin but other mycotoxins as well.

In addition to the risk attached to raw whole grains, feed producers should be aware of the higher risk of concentrated levels of mycotoxins that can be present in processed cereal by products like bran which is often used in pet food.

Fig 1. U.S Drought Monitor highlighting the drier than normal conditions in north and eastern regions (August 25, 2020)

Mycotoxin symptoms in dogs

While no pet owner wants to think about the risk of mycotoxins, it is important to know what to watch for to ensure early action can be taken where necessary to alleviate the problem. One of the primary signs of pets ingesting food contaminated with mycotoxins is liver damage, this can occur from either acute or chronic exposure. Other typical symptoms of mycotoxin contamination in dogs include:

• Vomiting and loss of appetite
• Weight loss
• Lethargy
• Diarrhea
• A weakened immune system
• Respiratory illnesses
• Tremors
• Heart palpitations
• Jaundice

Aflatoxin is one of the most potent mycotoxins and a known carcinogenic, and long-term exposure can lead to death, causing devastation for pet owners and their families.

If your dog displays any of these clinical signs, it is important to visit the veterinarian as soon as possible. Take a picture of your dog food and the bag’s lot number for reference, as well.

What are the regulations regarding aflatoxin?

The Food and Drugs Administration (FDA) regulates aflatoxin in feedstuffs and feeds. The current regulatory limit for pets (dogs, cats, rabbits, etc.) is 20 parts per billion (ppb).

In 2020, not only did aflatoxin’s geographic landscape grow — it also impacted the total corn yield. Decreased yield will necessitate moving greater amounts of corn around the country, further increasing the potential risk with corn in dog food.

Mitigating the threat of mycotoxins

To identify, manage and mitigate the mycotoxin challenge in feed production and to counteract the effects of mycotoxins before pets can encounter them, feed producers are advised to have a robust mycotoxin management plan in place, that can assess and manage risk at each step in the supply chain.  Modern, state-of-the-art testing, such as Alltech® 37+® and Alltech® RAPIREAD™,  can help to detect the mycotoxin risk and allow for the necessary control steps to be put in place.

For pet owners, where practical, it is encouraged to ask the manufacturer questions about their mycotoxin testing program and mitigation plan.

With a joined-up approach to mycotoxin management, the pet food industry can help to avoid a repeat of the recent feed recalls, and families can rest assured that they will not have to face up to the sad reality of losing a beloved pet.

For more information, please speak to your local Alltech representative or visit knowmycotoxins.com.  

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There has always been a threat of mycotoxin-contaminated feeds in the diets of terrestrially farmed animals as a result of the inclusion of high levels of cereals, and this has extended to include aquafeeds over the past few decades, as higher levels of cereals have become more commonplace. Mycotoxins in aquaculture and fish feed is an emerging and an underestimated problem for the industry.

What are mycotoxins?

Mycotoxins are chemical compounds produced by soil-borne "filamentous fungi". These lowly microbes are notorious plant pathogens in cereal crops, while their secondary metabolites, mycotoxins, are dangerous feed contaminants for farmed animals. It is possible for fungi to contaminate cereals in the early stages in the field, or later, during the transportation and storage of the commodities. Their growth, as well as the production of mycotoxins, is climate-dependent. That means that different fungi and mycotoxins bloom in different geographic regions.

For instance, Fusarium fungi flourish in temperate areas, and as a result, their corresponding mycotoxin, deoxynivalenol, is highly present. Similarly, in the tropics, the bloom of Aspergillus fungi is often linked to the release of aflatoxin. Unfortunately, the climate change and extreme weather conditions we are now experiencing may alter the fungal community structure and quantity of mycotoxin-producing fungi. Thus, in the coming years, we can expect an unavoidable and unpredictable increased risk of mycotoxins in our fields and agricultural commodities. 

The hidden threat to farmers

The aquafeed industry has made remarkable attempts to develop sustainable fish feeds by reducing the inclusion of traditionally used marine ingredients and replacing them with novel ingredients derived from crops and their byproducts. Thus, the inclusion of plant-based ingredients in fish diets, along with some known nutritional limitations, also introduces a potential exposure pathway for mycotoxins. To our knowledge, corn and its byproducts are the most highly contaminated with mycotoxins, followed by wheat and soybean products. If we consider the industry's long-term goal of reducing the value chain’s dependence on marine ingredients, then we can expect much higher inclusion rates of plant-derived raw materials in aquaculture feeds. Undoubtedly, these higher inclusion rates of plantstuffs, in combination with ongoing climate change, may boost the presence of mycotoxins in fish feeds, making the challenge of keeping contaminants out of fish feed even more difficult for the aquaculture industry.

Effects of mycotoxins on fish health and performance

Based on our established knowledge from the Alltech 37+ lab database, numerous individual mycotoxins have been detected in fish feed samples. In most cases, more than one mycotoxin is simultaneously present in a feed batch, at unpredictable levels and combination patterns. There are indications that some combinations might have synergetic effects on animals. However, the interactions among mycotoxins that co-occur in the feeds are not well-determined, as most of the research focuses on individual mycotoxins and not their combined toxicity.

An additional challenge to unraveling the effects of mycotoxins in aquaculture is the complexity of the industry itself. Fish farming is diverse and can include different fish species with different life histories, physiologies and, as a result, sensitivities to the toxins. The impacts of mycotoxins depend on various factors, including:

• The type and quantity of mycotoxins in the feed
• Feeding level
• The duration of exposure
• Fish species
• Sex
• Age
• Health
• The nutritional status of the exposed species

The biological effects of the most common mycotoxins (aflatoxin B1, ochratoxin A, fumonisin B1, deoxynivalenol, T-2 toxin and zearalenone) are described below based on studies on mammals.

As a result of the developing trend of mycotoxins in the aquaculture industry, scientists are undertaking research trials aimed at evaluating the impact of mycotoxins on fish species. Initial reports of the results are focused on growth trials, indicating that we still have quite a long way to go. Regardless of the type of toxin, reduced growth performance and high feed-conversion ratios are often associated with the ingestion of contaminated feeds.

Growth might be affected directly, due to lower intakes of contaminated feeds, or indirectly, due to the molecular damage the toxins induce on the cellular level. In any case, the final output is the same: reduced growth performance for the fish and economic losses for the fish farmers. Unfortunately, mycotoxin contamination is a “silent” enemy for farmers, since most cases are not correlated with visual symptoms. Long-term ingestion of feeds with low levels of mycotoxins or acute exposure to high levels might be a reason for the unexplained mortalities that occasionally are observed in fish farms.

The solution

Sustainability is our priority, and we feel we have a responsibility to establish and maintain an aquaculture industry that protects farmed fish welfare, helps farmers maximize their profits and creates sustainable products that are essential for consumers to live a healthy balanced lifestyle.

To properly manage the mycotoxin risk at the industrial level, it is crucial to examine potential solutions at all of the critical points in the value chain, from the fields to the feed mills. Starting in the fields, good agricultural practices — like growing resistant crop varieties, crop rotation, soil tillage, and chemical and biological control of plant diseases — are recommended.

At the pre-harvest stage, mycotoxin contamination cannot be fully prevented, especially during unpredictable weather conditions. Raw material suppliers should implement methods for rapid mycotoxin analyses in cereal products to accept or reject a batch. Unfortunately, these quick tests can only detect a few toxins, and the regulatory limits vary among different countries. Thus, the responsibility of mycotoxin management in aquafeeds is automatically transferred to the aquafeed producers.

At this final stage, mold inhibitors are usually included in the feed formulations to prevent fungal growth in the finished feeds during storage. Mycotoxins produced in the pre-harvest stage are still present in the feeds and remain almost stable in high temperatures during the extrusion process. As such, feed producers should consider detoxification feeding strategies in order to eliminate the negative impacts of mycotoxins on fish after exposure. 

Among different commercially available detoxification products, enzymes appear to have a high selectivity in transforming mycotoxins to less toxic forms. However, this strategy would only be effective if aquafeeds contained just one mycotoxin. In reality, as mentioned previously, a cocktail of mycotoxins is likely to be present in the feeds, and it is not feasible to supplement an enzyme for each potential toxin. As a result, attention is shifting to more practical and universal solutions, such as mycotoxins binders. In general, organic adsorbents bind with a larger spectrum of mycotoxins than the inorganic ones.

Overall, effective mycotoxin management is about seeing the whole challenge, from the farm to the feed mill and from risk assessment to feed management. The symptoms can be many and varied, but the outcome in all cases will be reduced performance and lost profits. The Alltech Mycotoxin Management team provides a number of solutions to help you mitigate the threat you could face from field or storage mycotoxins. Speak to the aquaculture team today and find out how you can mitigate the threat of mycotoxins in your feed. Email aquasolutions@alltech.com.

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