Feed Testing for Mycotoxins: When and How to Test

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-08-14

Key Takeaways

• Test new loads of high-risk feed (corn, small grains, distillers grains, cottonseed) before feeding to sensitive animals (dairy cows, young stock, breeding animals) and whenever visible mold, musty odors, heating, or moisture damage are observed.
• Collect representative samples by taking at least 10-20 subsamples from different locations and depths within a feed batch, combining them into an aggregate sample, and reducing it to the required size using a sample splitter or coning and quartering.
• Utilize laboratories employing validated analytical methods such as HPLC or LC-MS/MS for accurate mycotoxin quantification, and test for a panel of common toxins including aflatoxins, DON, fumonisins, zearalenone, T-2 toxin, and ochratoxin A.
• Interpret test results against species-specific guidance levels (e.g., FDA advisory levels for aflatoxin and DON) and consider the combined effects of multiple mycotoxins in the total ration, as synergistic toxicity can exacerbate negative impacts.
• Maintain meticulous records of all feed tests, including sample collection date, location, feed batch, laboratory results, and actions taken, to facilitate pattern recognition, justify management decisions, and provide evidence in case of disputes.
• Consult a veterinarian or extension agent when animals exhibit unexplained performance drops, clinical signs of mycotoxicosis, or when test results are high or borderline, to ensure appropriate diagnosis, treatment, and risk mitigation strategies.

Mold toxins in livestock feed are a quiet threat. They do not always announce themselves with visible mold, strange odors, or sick animals. By the time you notice reduced intake, lower milk production, or poor weight gain, the toxins have already been working against your herd or flock for days or weeks. This guide explains when to test feed for mycotoxins, how to collect samples that give you trustworthy results, and what to do with the numbers once you have them. It is written for livestock producers, feed managers, and farm advisers who need practical answers about mycotoxin testing in feed, not laboratory theory.

At a Glance

• Test any new load of grain or complete feed before feeding it to breeding stock, young animals, or high-producing dairy cows.
• Test when you see signs of mold, musty smell, heating in storage, or visible moisture damage, even if animals look fine.
• Test when animals show unexplained drops in intake, milk production, or weight gain that do not match a disease pattern.
• Collect a representative sample. A single handful from the top of a bin is not enough. Take multiple subsamples from different locations and depths.
• Send samples to a laboratory that uses validated methods such as HPLC, LC-MS/MS, or ELISA for the specific mycotoxins you want measured.
• Test for multiple toxins, not just aflatoxin. Deoxynivalenol (DON), fumonisins, zearalenone, T-2 toxin, and ochratoxin are common problems in many regions.
• Interpret results against the guidance levels for your species and production stage. A level that is safe for beef cattle can harm pigs or poultry.
• Keep records of every test result, sample location, feed batch, and the action you took. These records protect you in a dispute and help you spot patterns.
• Call your veterinarian or extension agent when test results are high, when animals are sick, or when you are not sure how to interpret a borderline result.

Understanding Mycotoxins in Livestock Feed

Mycotoxins are toxic compounds produced by certain species of molds. The molds grow on crops in the field, during harvest, or in storage when moisture and temperature conditions favor them. The toxin itself is the chemical the mold produces. The mold can be dead, killed by heat, or removed by processing, but the toxin can remain in the feed and still cause harm.

There are hundreds of known mycotoxins. A handful of them cause most of the economic damage in livestock production. The major ones you need to know are aflatoxins, deoxynivalenol (also called DON or vomitoxin), fumonisins, zearalenone, T-2 toxin, and ochratoxin A. Each one comes from different mold species, affects different animals differently, and has different action thresholds.

Aflatoxins

Aflatoxins come mainly from Aspergillus flavus and Aspergillus parasiticus. These molds thrive in warm, humid conditions. They are most common in corn, peanuts, cottonseed, and other oilseed crops grown in hot climates. Aflatoxin B1 is the most toxic form and is a known liver carcinogen. It is also the form that carries over into milk as aflatoxin M1, which is why dairy farmers have strict limits on aflatoxin in feed. Aflatoxin testing in feed is most urgent for dairy operations and for young animals of any species.

Deoxynivalenol (DON, Vomitoxin)

DON is produced by Fusarium graminearum and related species. It is common in wheat, barley, corn, and other small grains in cooler, wet growing seasons. DON is a vomitoxin. It causes feed refusal, reduced intake, and vomiting in pigs at relatively low levels. Ruminants tolerate higher levels because the rumen microbes break down the toxin, but high levels can still reduce intake and performance.

Fumonisins

Fumonisins come from Fusarium verticillioides and Fusarium proliferatum. They are primarily a problem in corn. Fumonisin B1 is the main form. In horses, fumonisins cause a fatal brain disease called leukoencephalomalacia. In pigs, they cause pulmonary edema. In ruminants, they are less toxic but can still affect liver function and immune response. Horses are the most sensitive species to fumonisins.

Zearalenone

Zearalenone is also produced by Fusarium species, especially Fusarium graminearum. It has estrogen-like activity. It causes reproductive problems in pigs, including swollen vulvas in gilts, reduced litter size, and fertility issues in sows. Dairy cattle can show reduced fertility and milk production. The effects are often subtle and can be mistaken for other reproductive problems.

T-2 Toxin

T-2 toxin is produced by Fusarium sporotrichioides and related species. It is highly toxic and causes irritation to the digestive tract, reduced feed intake, weight loss, and immune suppression. Poultry are especially sensitive. T-2 toxin can also cause lesions on the mouth and beak in birds.

Ochratoxin A

Ochratoxin A comes from Aspergillus ochraceus and Penicillium verrucosum. It is a kidney toxin and can cause kidney damage in pigs and poultry. It is more common in temperate climates and in stored grain that has been kept too wet.

When to Test Feed for Mycotoxins

You cannot manage what you do not measure. Testing feed for mold toxins is the only way to know what is actually in the feed. The question is not whether testing is useful. The question is when the cost of testing is justified by the value of the information.

Test Every New Load of High-Risk Feed

Certain feeds carry a higher risk of mycotoxin contamination. Corn, corn silage, wheat, barley, distillers grains, cottonseed, peanuts, and any feed that has been stored for a long time are all higher risk. If you buy these feeds in bulk, test each new load before feeding it to your most sensitive animals. The cost of a mycotoxin panel is small compared to the cost of a drop in milk production, a reproductive failure, or a death loss.

Test When You See or Smell Problems

Visible mold is an obvious reason to test. But the absence of visible mold does not mean the feed is safe. Mold can be present without being visible to the naked eye. Heat damage, a musty or sour smell, caked feed, or moisture condensation inside a bin are all warning signs. If the feed looks or smells off, test it before feeding.

Test When Animals Show Unexplained Problems

The most common reason farmers test feed is because animals are not performing as expected. Watch for these signs:

• Reduced feed intake without an obvious cause
• Drop in milk production in dairy cows
• Poor weight gain in growing animals
• Increased incidence of digestive upset or loose manure
• Vomiting, especially in pigs
• Reduced fertility, small litters, or reproductive problems
• Immune suppression with increased infections
• Liver or kidney problems confirmed by a veterinarian
• Sudden death, especially in horses or pigs

If several animals show the same problem at the same time and you cannot find a disease explanation, suspect the feed. Test the feed you are currently feeding and any feed that was fed in the previous two to three weeks.

Test at Key Points in the Feeding Year

Some times of year carry higher risk. In humid climates, the risk of aflatoxin is highest in late summer and early fall. In cooler, wet climates, the risk of Fusarium toxins like DON and zearalenone is highest when harvest conditions are wet. Feed that has been stored through a hot, humid summer is at higher risk when you open it in the fall. Test at these seasonal transition points, even if you have not seen problems.

Test Before Feeding High-Risk Groups

Certain animals are more sensitive to mycotoxins. Test feed before giving it to:

• Dairy cows, especially those in early lactation
• Breeding sows and gilts
• Young animals of any species
• Horses, which are extremely sensitive to fumonisins
• Poultry, especially young birds

If you have a limited testing budget, prioritize testing feed that will go to these groups.

How to Collect a Feed Sample for Mycotoxin Testing

The accuracy of mycotoxin analysis depends more on sampling than on the laboratory method. Mycotoxins are not distributed evenly through a load of feed. One handful of grain can have a very high concentration while another handful from the same load has almost none. A poor sample can give you a false sense of security or cause you to discard feed that is actually safe.

Use the Right Sampling Tools

For grain, use a grain probe or grain trier that can reach deep into the bin or truck. A probe that takes a core from the full depth of the grain is ideal. For ground feed or complete feed, use a sampling spear or thief that can take a core from a bag, tote, or bin. Do not use your hands. Your hands only sample the surface, and surface samples are not representative.

Take Multiple Subsamples

A single probe is never enough. The standard recommendation is to take at least 10 to 20 subsamples from different locations and depths within a load or bin. For a truckload of grain, sample from multiple points across the surface and at different depths. For a bin, sample from the center and from several points around the edges, at multiple depths. For bags or totes, sample from several different bags or containers. Combine all the subsamples into one clean bucket and mix them thoroughly. This combined sample is called the aggregate sample.

Reduce the Sample to the Right Size

Laboratories usually need about 500 grams to 1 kilogram of sample for a comprehensive mycotoxin panel. Your aggregate sample may be much larger. You need to reduce it without introducing bias. The best method is to use a sample splitter, which divides the sample into equal portions. If you do not have a splitter, use the quartering method. Pour the aggregate sample onto a clean flat surface, mix it thoroughly, divide it into four equal quadrants, take two opposite quadrants, mix those, and repeat until you have the right amount. This is called coning and quartering.

Use Clean Containers

Use a clean, dry plastic bag or a clean glass jar. Do not use paper bags, because moisture can wick through the paper and change the sample. Label the container clearly with the date, the feed type, the batch or lot number, and the location where the sample was taken. Seal the container tightly.

Store and Ship the Sample Properly

Keep the sample cool and dry until you can ship it. Do not leave it in a hot truck or in direct sunlight. Ship it to the laboratory as soon as possible. Most laboratories can handle samples sent by regular mail or courier. Check with the laboratory for their specific shipping requirements.

Take a Second Sample for Your Records

If you are testing because you suspect a problem, take a second aggregate sample and store it in your freezer. If there is a dispute with your feed supplier, or if animals get sick and you need to prove what was in the feed, you will have a backup sample that has been preserved.

Choosing a Laboratory and a Test Package

Not all laboratories are the same. Some specialize in feed analysis, some in environmental testing, and some in human food safety. Choose a laboratory that has experience with livestock feed and that uses validated methods for mycotoxin analysis.

Ask About Methods

The most reliable methods for mycotoxin testing are high-performance liquid chromatography (HPLC) and liquid chromatography with tandem mass spectrometry (LC-MS/MS). These methods can measure multiple toxins at once and are accurate at low levels. Enzyme-linked immunosorbent assay (ELISA) is a faster and cheaper method that many laboratories use for screening. ELISA is useful for a quick answer, but it can have more variability than HPLC or LC-MS/MS. If you get a borderline or high result from an ELISA test, consider confirming it with HPLC or LC-MS/MS.

Ask About the Panel

The laboratory should offer a panel that covers the major toxins relevant to your region and your species. A basic panel should include aflatoxin, DON, fumonisins, zearalenone, T-2 toxin, and ochratoxin A. Some laboratories offer expanded panels that include additional toxins like HT-2, citrinin, or ergot alkaloids. If you have reason to suspect a specific toxin, ask the laboratory if they can test for it.

Ask About Detection Limits

The laboratory should report the detection limit for each toxin. The detection limit is the lowest concentration the method can reliably measure. Make sure the detection limit is low enough to be meaningful for your species. For example, the action level for aflatoxin in dairy feed in the United States is 20 parts per billion (ppb). If the laboratory detection limit is 10 ppb, that is fine. If the detection limit is 25 ppb, the laboratory cannot tell you whether the feed is safe for dairy cows.

Ask About Turnaround Time

Routine testing usually takes 3 to 7 business days. If you need a faster answer, some laboratories offer rush service for an additional fee. If animals are sick and you need to make a feeding decision quickly, ask about rush options. A rapid screening test like ELISA can give you an answer in a day or two, but you may need to confirm with a more accurate method later.

Ask About Sample Requirements

Different laboratories have different requirements for sample size, packaging, and shipping. Call the laboratory before you send a sample and ask for their specific instructions. Some laboratories provide sample submission forms and prepaid shipping labels. Use these to make sure your sample is processed correctly.

Understanding Mycotoxin Test Results

Once you have test results, you need to know what they mean. The numbers are meaningless without context. You need to know the guidance level for your species and production stage, and you need to know how the toxin level in the test sample relates to what the animals are actually eating.

Know the Guidance Levels for Your Species

Different species have different tolerance levels for each mycotoxin. The United States Food and Drug Administration (FDA) has published advisory levels for some mycotoxins in animal feed. Other countries and organizations have their own guidance. Your extension agent or veterinarian can help you find the applicable guidance for your region.

Here are some general reference points for common mycotoxins. These are not regulatory limits and they vary by country and by animal species. Use them as a starting point for discussion with your veterinarian or extension agent.

For aflatoxin, the FDA advisory level for dairy cattle and young animals is 20 parts per billion (ppb). For breeding cattle, swine, and mature poultry, the level is 100 ppb. For finishing swine and finishing poultry, the level is 200 ppb. For beef cattle, the level is 300 ppb. These levels are designed to keep aflatoxin from entering milk and to protect animal health.

For DON, the FDA advisory level for grain and grain byproducts is 5 parts per million (ppm) for cattle and chickens, 10 ppm for ruminating beef cattle and dairy cattle over four months old, and 1 ppm for swine. The key point is that swine are much more sensitive to DON than ruminants.

For fumonisins, the FDA guidance level for horses is 5 ppm total fumonisins in the total ration. For swine, the level is 20 ppm in the total ration. For ruminants, the level is 30 ppm in the total ration for breeding stock and 60 ppm for animals being finished for slaughter. Horses are the most sensitive species by far.

For zearalenone, there is no FDA advisory level. Many countries have guidance levels ranging from 0.1 to 1.0 ppm depending on the species and the production stage. Swine, especially young gilts and breeding sows, are the most sensitive.

For T-2 toxin and ochratoxin A, there are no widely established advisory levels in the United States. Many European countries have guidance levels. Poultry and swine are the most sensitive species.

Interpret Results in the Context of the Total Ration

Test results are usually reported as the concentration of toxin in the feed sample. But the animal eats a total ration that may include multiple ingredients. If you test a single ingredient like corn and find 2 ppm DON, you need to calculate how much DON the animal is getting in the complete ration. If corn makes up 50 percent of the ration, the DON level in the complete ration is 1 ppm. That is safe for cattle but not for swine.

Consider the Combined Effects of Multiple Toxins

Animals are often exposed to more than one mycotoxin at a time. The combined effect can be worse than the effect of each toxin alone. This is called synergism. For example, a feed with 1 ppm DON and 0.5 ppm zearalenone may cause more problems than a feed with 2 ppm of either toxin alone. Some laboratories offer a combined risk assessment that considers the total mycotoxin load. Ask your laboratory or your veterinarian about this.

Do Not Ignore Borderline Results

A result that is just below the guidance level is not a green light to ignore the feed. It is a signal to monitor closely. Feed the borderline feed to less sensitive animals, dilute it with clean feed, or use a mycotoxin binder if your veterinarian recommends one. Re-test if you have any reason to think the contamination is uneven.

Common Mistakes in Mycotoxin Testing

Farmers make several predictable mistakes when testing feed for mycotoxins. Avoiding these mistakes will save you money and protect your animals.

Mistake 1: Testing Only Visible Mold

Visible mold is not the same as mycotoxin contamination. Some molds that produce toxins are not visible to the naked eye. Conversely, some visible mold does not produce significant toxins. Testing only visibly moldy feed will miss contaminated feed that looks clean.

Mistake 2: Taking a Single Handful Sample

A single handful from the top of a bin is not representative. Mycotoxins are distributed unevenly. You need multiple subsamples from different locations and depths, combined into one aggregate sample.

Mistake 3: Testing Only for Aflatoxin

Aflatoxin gets the most attention because it is regulated and because it carries into milk. But DON, fumonisins, zearalenone, and T-2 toxin are common problems in many regions. If you only test for aflatoxin, you will miss the toxins that are actually causing your problems.

Mistake 4: Not Storing a Backup Sample

If you do not store a backup sample, you have no way to verify a result or to pursue a claim against a feed supplier. Always take a second sample and freeze it.

Mistake 5: Testing Feed That Is Not What the Animals Are Eating

Testing a sample from an old batch of feed when the animals are eating a new batch tells you nothing about the current risk. Test the feed that is in the feeder or the feed that will be fed next.

Mistake 6: Ignoring the Sample Collection Date

Mycotoxin levels can change during storage. Feed that was safe when it was harvested can become contaminated after months in a damp bin. Always record the collection date and re-test feed that has been stored for a long time.

Mistake 7: Interpreting Results Without Species Context

A result of 2 ppm DON is a serious problem for pigs but a minor issue for beef cattle. Do not panic or dismiss results without checking the guidance level for your species and production stage.

Mistake 8: Not Using a Certified Laboratory

A laboratory that is not accredited or that does not use validated methods can give you unreliable results. Use a laboratory that participates in proficiency testing and that can show you their quality control data.

What to Do with High Mycotoxin Test Results

A high test result is not the end of the world. You have options. The right option depends on the toxin, the level, the species, and your situation.

Do Not Feed Contaminated Feed to Sensitive Animals

The first step is to stop feeding the contaminated feed to your most sensitive animals. This includes dairy cows, breeding stock, young animals, horses, and poultry. If you have other animals that are less sensitive, you may be able to feed the contaminated feed to them, but only after you have calculated the dose and checked the guidance levels.

Dilute Contaminated Feed with Clean Feed

Dilution is a common strategy. If you have feed with 2 ppm DON and you need to get it below 1 ppm for swine, you can mix it 50:50 with clean feed that has no detectable DON. This works only if you have a reliable supply of clean feed and if you can mix thoroughly enough to avoid hot spots. Incomplete mixing can leave pockets of high toxin concentration that defeat the purpose.

Use a Mycotoxin Binder or Adsorbent

Mycotoxin binders are feed additives that bind to toxins in the digestive tract and reduce their absorption. Common binders include clay products like bentonite, yeast cell wall products, and activated carbon. Binders are not equally effective for all toxins. Some binders work well for aflatoxin but poorly for DON or zearalenone. Talk to your veterinarian about which binder is appropriate for your specific toxin problem. Binders are a management tool, not a cure. They reduce the effect of the toxin but do not eliminate it.

Process the Feed to Reduce Toxin Levels

Some processing methods can reduce mycotoxin levels. Heat treatment can reduce some toxins but not others. Ozone treatment, ammoniation, and certain chemical treatments have been studied for aflatoxin reduction in some countries. These methods are not widely available and may not be practical on a farm scale. Do not assume that pelleting or roasting removes mycotoxins. Some toxins are heat-stable and survive normal feed processing.

Discard Severely Contaminated Feed

If the toxin level is very high, or if you cannot safely dilute or bind the toxins, discard the feed. The cost of discarding feed is less than the cost of sick animals, lost production, and potential regulatory action. Do not feed severely contaminated feed to animals that will be used for breeding or for milk production.

Consult Your Veterinarian

If animals are already showing signs of mycotoxicosis, call your veterinarian. The clinical signs of mycotoxicosis can look like many other diseases. Your veterinarian can help you rule out other causes, treat affected animals, and advise you on the best course of action. Do not try to diagnose or treat mycotoxicosis on your own.

Monitoring and Recordkeeping

Mycotoxin testing is not a one-time event. It is part of an ongoing feed safety program. Good recordkeeping helps you spot patterns, justify decisions, and protect yourself in disputes.

Keep a Feed Testing Log

For every sample you submit, record the following information in a logbook or spreadsheet:

• Date of sample collection
• Date the sample was sent to the laboratory
• Laboratory name and test method
• Feed type and batch or lot number
• Source of the feed (your own field, a specific supplier, a specific load)
• Storage location and conditions
• Sample collection method and number of subsamples
• Test results for each mycotoxin
• Action taken based on the results
• Any animal health or performance observations

Track Results Over Time

If you test the same type of feed from the same source over several seasons, you can build a picture of your risk. A field that consistently produces corn with elevated DON in wet years is a field you should test every year. A supplier who has never had a problem is still worth testing, but you may test less frequently.

Monitor Animal Performance

Feed testing is only useful if you connect it to animal performance. Track feed intake, milk production, weight gain, reproductive performance, and health events. If you see a pattern of problems that coincides with a particular feed batch, you have valuable information for your next management decision.

Work with Your Extension Agent

Your local cooperative extension agent is a free resource. Extension agents can help you interpret test results, recommend sampling protocols, and connect you with laboratories and other experts. Many extension services publish fact sheets on mycotoxin management for their region. These fact sheets are tailored to local crops, climate, and regulations.

When to Call a Veterinarian or Extension Agent

You do not need to call an expert for every test result. But there are situations where professional advice is essential.

Call Your Veterinarian When Animals Are Sick

If animals are showing clinical signs of mycotoxicosis, call your veterinarian immediately. Clinical signs include vomiting, reduced feed intake, diarrhea, poor growth, reproductive failure, immune suppression, and sudden death. Your veterinarian can examine the animals, rule out infectious diseases, and recommend treatment. Do not wait for test results to come back before calling. The test results will help confirm the diagnosis, but your veterinarian can start working on the problem right away.

Call Your Veterinarian When Test Results Are Very High

If a test result is well above the guidance level for your species, call your veterinarian before feeding the feed to any animal. Your veterinarian can help you calculate the risk and decide whether to dilute, bind, or discard the feed.

Call Your Extension Agent When You Are Not Sure How to Interpret Results

If you have a test result that is borderline, or if you are not sure which guidance level applies to your situation, call your extension agent. Extension agents can help you find the applicable guidance for your region and species. They can also help you understand the limitations of the test method and whether you need a confirmatory test.

Call Your Extension Agent When You Are Developing a Monitoring Plan

If you are starting a mycotoxin testing program for the first time, or if you want to improve your existing program, your extension agent can help. They can recommend sampling protocols, help you choose a laboratory, and advise you on how often to test.

Call a Regulatory Authority When Required

In some situations, you are required to report mycotoxin contamination. If you suspect that contaminated feed has entered the human food chain, or if you are a commercial feed manufacturer and your product exceeds regulatory limits, you may have a legal obligation to report. Your extension agent or veterinarian can help you determine whether reporting is required in your situation.

Frequently Asked Questions

How often should I test my feed for mycotoxins?

There is no single answer that fits every farm. The right frequency depends on your risk. If you buy feed from commercial suppliers, test each new load of high-risk ingredients like corn, distillers grains, or cottonseed. If you grow your own grain, test at harvest and again after several months of storage. Test any time you see mold, smell a musty odor, or notice animal performance problems. As a general rule, the more sensitive your animals and the higher the risk of contamination, the more often you should test.

What is the difference between a screening test and a confirmatory test?

A screening test, usually an ELISA, gives a quick answer at a lower cost. It is useful for deciding whether a problem might exist. A confirmatory test, usually HPLC or LC-MS/MS, is more accurate and can measure multiple toxins at low levels. If a screening test shows a high result, you should confirm it with a more accurate method before making a major decision like discarding feed or filing a claim against a supplier.

Can I test feed on my farm with a test kit?

Yes, there are on-farm test kits available, mostly based on lateral flow or ELISA technology. These kits can give you a quick answer in a few minutes. They are useful for screening, but they are not as accurate as laboratory methods. If you use an on-farm kit, follow the instructions exactly and confirm any positive or borderline results with a laboratory test.

How much does mycotoxin testing cost?

The cost varies by laboratory, by the number of toxins tested, and by the method used. A basic ELISA panel for five or six common mycotoxins might cost 50 to 150 dollars. A comprehensive LC-MS/MS panel can cost 150 to 300 dollars or more. The cost is small compared to the value of the information. A single case of mycotoxin-related production loss can cost far more than a year of testing.

What is a mycotoxin binder and should I use one?

A mycotoxin binder is a feed additive that binds to toxins in the digestive tract and reduces their absorption into the body. Common binders include clay minerals, yeast cell wall products, and activated carbon. Binders are not equally effective for all toxins. They tend to work better for aflatoxin than for DON or zearalenone. Talk to your veterinarian before using a binder. Binders are a management tool, not a substitute for testing and good feed management.

Can I feed moldy feed to beef cattle if I mix it with clean feed?

Dilution can work, but only if you calculate the dose correctly and mix thoroughly. Beef cattle are more tolerant of some mycotoxins than pigs, poultry, or horses. However, you must know the toxin level in the contaminated feed, the toxin level in the clean feed, and the guidance level for beef cattle. Mixing must be thorough enough to avoid hot spots. When in doubt, call your veterinarian or extension agent before feeding.

Will cooking or roasting the feed kill the mycotoxins?

No. Mycotoxins are heat-stable compounds. Normal feed processing temperatures, including pelleting, roasting, and extrusion, do not reliably destroy mycotoxins. Some processing methods can reduce certain toxins, but none of them eliminate the risk entirely. Do not assume that processed feed is safe. Test the finished feed if you have concerns.

What are the signs of mycotoxicosis in cattle?

The signs depend on the toxin and the dose. Common signs include reduced feed intake, lower milk production, poor weight gain, diarrhea, reduced fertility, and increased susceptibility to infections. Aflatoxin can cause liver damage and jaundice. Zearalenone can cause reproductive problems. The signs are often subtle and can be mistaken for other diseases. If you see a pattern of poor performance across multiple animals, suspect the feed and test it.

Related Farming Guides

This section will be populated programmatically with links to related farming guides on feed management, livestock nutrition, and animal health topics.

Related Clinical & Scientific Guides

• Animal Welfare Audits: Building a Useful Farm Program
• Total Mixed Ration (TMR) for Dairy: Mixing and Feeding Management
• Feed Additives for Livestock: Probiotics, Enzymes, and More

References

• USDA Farm Management: https://www.farmers.gov/
• FAO Farm Management: https://www.fao.org/farmer-field-schools/en/
• FAO Animal Production and Health: https://www.fao.org/animal-production/en/
• WOAH (World Organisation for Animal Health): https://www.woah.org/en/home/

This article is educational and is not a substitute for veterinary diagnosis, treatment, public-health guidance, or regulatory reporting.