# Swine Feed Storage and Mycotoxin Management ## Key Takeaways - **Moisture and Temperature Control:** Maintain grain moisture below 13% and finished feed below 12% to inhibit mold growth. Store feed bins below 70°F when possible, as temperature fluctuations create condensation, a critical factor for mold proliferation. - **Mycotoxin Identification and Impact:** Key mycotoxins affecting swine include aflatoxins (liver damage, immunosuppression), DON (reduced intake, immune suppression), zearalenone (reproductive issues), fumonisins (lung/liver damage), ochratoxin A (kidney damage), and T-2 toxin (oral/GI irritation). Multiple toxins can exhibit synergistic effects. - **Preventative Storage Practices:** Implement a first-in, first-out rotation system, clean storage facilities thoroughly before refilling, and inspect feed visually and by smell at every delivery and feeding. Source quality ingredients from reputable suppliers and dry grain promptly after harvest. - **Risk-Based Testing Protocols:** Test feed for mycotoxins when visible mold is present, after moisture exposure, or when pigs exhibit unexplained performance declines (e.g., reduced feed intake, poor growth, reproductive issues). Work with veterinary professionals to establish specific action thresholds for detected toxins. - **Dilution and Binder Strategies:** For moderate contamination, dilute with clean feed to reduce toxin levels below action thresholds. Mycotoxin binders, particularly aluminosilicates for aflatoxins, can be used to reduce absorption, but do not replace proper storage and testing. - **Comprehensive Monitoring and Recordkeeping:** Conduct daily visual checks of feed storage and feeders, weekly inspections of grain condition, and monthly inventory reviews. Maintain detailed records of feed deliveries, storage conditions, cleaning, testing results, and any observed health or performance anomalies. --- Feed represents one of the largest ongoing costs in swine production, often accounting for 60 to 70 percent of total production expenses. Protecting that investment through proper storage and mycotoxin management is not just about preventing waste. It is about protecting herd health, growth performance, and reproductive outcomes. This guide covers the full scope of swine feed storage and mycotoxin management, from understanding how toxins develop to implementing practical storage systems, testing protocols, and response plans. It is written for swine producers, farm managers, and employees who handle feed daily and need clear, actionable guidance to protect their herds. ## At a Glance Key takeaways for protecting swine feed from spoilage and mycotoxin contamination: - Store feed ingredients in clean, dry, well-ventilated facilities that protect against moisture and pests. - Keep moisture content below 13 percent for stored grains and below 12 percent for longer-term storage. - Maintain feed bins and storage areas at temperatures below 70 degrees Fahrenheit when possible. - Use a first-in, first-out rotation system so feed does not sit in storage for extended periods. - Inspect feed visually and by smell at every delivery and before every feeding. - Test feed for mycotoxins when you see mold, when feed has been exposed to moisture, or when pigs show unexplained performance problems. - Work with a veterinarian or extension agent to establish action thresholds for specific mycotoxins. - Clean feed storage equipment regularly, including bins, augers, and feeders, to remove caked and spoiled feed. - Keep detailed records of feed deliveries, storage conditions, and any contamination events. ## Understanding Mycotoxins in Swine Feed Mycotoxins are toxic compounds produced by certain species of fungi, or molds, that grow on feed ingredients. These molds are common in the environment and can contaminate crops in the field, during harvest, or while in storage. The toxins themselves are stable compounds that survive processing and remain in the finished feed. This means that even if you do not see visible mold, mycotoxins can still be present and affecting your pigs. The most significant mycotoxins for swine production include aflatoxins, deoxynivalenol (DON, also called vomitoxin), zearalenone, fumonisins, ochratoxin A, and T-2 toxin. Each of these affects pigs differently, and the severity of the impact depends on the toxin level, the duration of exposure, the age and health status of the pig, and whether multiple toxins are present simultaneously. Aflatoxins are produced by Aspergillus species and primarily damage the liver. They also suppress the immune system, making pigs more susceptible to infectious diseases. High levels can cause acute illness and death, while chronic low-level exposure reduces growth rates and feed efficiency. Deoxynivalenol, commonly called DON or vomitoxin, is produced by Fusarium species. It causes reduced feed intake, vomiting at high levels, and immune suppression. Pigs are particularly sensitive to DON compared with other livestock species. Zearalenone is also produced by Fusarium species. It mimics estrogen in the body and causes reproductive problems, especially in gilts and sows. Signs include swollen vulvas in prepubertal gilts, reduced litter sizes, and irregular estrus cycles. Fumonisins are produced by Fusarium species and primarily affect the lungs and liver in pigs. They can cause pulmonary edema, which is fluid accumulation in the lungs, and can be fatal at high levels. Ochratoxin A is produced by Penicillium and Aspergillus species. It damages the kidneys and can reduce growth performance. This toxin is more common in cooler, damp storage conditions. T-2 toxin is produced by Fusarium species and causes severe oral and gastrointestinal irritation. Pigs may refuse feed, develop mouth lesions, and show reduced growth. The challenge with mycotoxin management is that multiple toxins often occur together. When this happens, the combined effect can be worse than the sum of their individual effects. This synergistic interaction makes it difficult to predict the impact on the herd based on testing for a single toxin. ## How Mold and Mycotoxins Develop Understanding the conditions that allow mold growth is the foundation of effective prevention. Molds need three things to grow: moisture, oxygen, and a suitable temperature. If you can control any one of these, you can significantly reduce the risk of contamination. Moisture is the most critical factor. Feed ingredients with moisture content above 13 to 14 percent provide enough water for mold growth. The exact threshold varies by ingredient and storage temperature, but the general rule is that drier feed is safer feed. Moisture can enter the feed system in several ways. Grain may be harvested too wet. Condensation can form on bin walls during temperature changes. Rain can leak through damaged roofs or loose bin lids. Ground feed can absorb moisture from humid air during storage. Temperature also plays a major role. Most molds that affect feed grow well between 50 and 100 degrees Fahrenheit, with optimal growth around 77 to 86 degrees. However, some molds can grow at cooler temperatures, which is why mold can develop even in winter storage. The key is that temperature fluctuations cause condensation, and condensation creates localized moisture that supports mold growth. Oxygen is harder to control in most storage situations. Whole grain stored in a sealed bin will consume oxygen through respiration, creating conditions that limit mold growth. However, ground feed has more surface area and more trapped oxygen, so it spoils faster than whole grain. This is one reason why grinding feed just before feeding is preferable to grinding and storing large quantities. Time is the final factor. Molds need time to establish and produce toxins. Feed stored for weeks or months has more opportunity for contamination than feed used within days. The longer the storage period, the more important it is to have proper moisture control and regular inspection. Field conditions also matter. Molds that produce mycotoxins can infect crops while they are still growing. Drought stress, insect damage, and delayed harvest all increase the risk of Fusarium contamination in the field. This means that some mycotoxin risk is present before the grain ever reaches your storage facility. Knowing the growing conditions in your region and sourcing grain from reliable suppliers can help manage this risk. ## The Costs of Poor Feed Storage The financial impact of poor feed storage goes far beyond the value of spoiled feed that must be discarded. Mycotoxin contamination can cause production losses that far exceed the cost of the feed itself, even when the contamination is not severe enough to cause obvious illness. Reduced feed intake is often the first sign. Pigs naturally avoid feed that tastes or smells off, and some mycotoxins like DON directly affect the appetite centers in the brain. A 5 to 10 percent reduction in feed intake may not be noticeable in a single day, but over a finishing period it translates directly into slower growth and more days to market weight. Feed conversion efficiency also suffers. Even when pigs eat the same amount of feed, mycotoxins can interfere with nutrient absorption and metabolism. The result is that pigs need more feed to gain the same amount of weight, increasing the cost per pound of gain. Immune suppression is a hidden cost that can be substantial. Pigs exposed to mycotoxins are more susceptible to respiratory disease, enteric infections, and other common swine diseases. This can mean higher medication costs, more mortality, and more variation in pig performance. In breeding herds, reproductive losses from zearalenone can reduce the number of pigs weaned per sow per year. There is also the risk of condemnation or residue concerns. While mycotoxins are not typically a [food safety](/knowledge/bacteria/livestock-bacteria/cooking-chicken-bacteria-prevention) issue in pork in the same way they are in milk, severe contamination can affect liver and kidney quality at slaughter. Some buyers have their own testing programs, and a load of pigs with contaminated livers may be discounted or rejected. The practical takeaway is that investment in proper storage infrastructure and monitoring is cheap compared with the potential losses from a mycotoxin outbreak. A simple moisture meter costs a few hundred dollars. A single contaminated bin of feed can cost thousands in lost performance and discarded feed. ## Designing a Proper Feed Storage System A well-designed feed storage system starts with the facility and equipment. The goal is to keep feed dry, cool, and protected from pests while allowing easy access for inspection and cleaning. ### Grain and Ingredient Storage Whole grain storage requires bins or silos that protect against moisture. Look for bins with sound roofs, tight-fitting lids, and no leaks. The bin should be elevated or have a concrete pad that keeps the bottom dry and prevents ground moisture from wicking up into the grain. Check that the bin has proper ventilation to allow air movement and reduce condensation. Before filling a bin, clean it thoroughly. Remove all old grain, dust, and debris from the previous season. Pay special attention to the bottom and the walls where old grain can cake and harbor mold spores. If you suspect mold in the bin, wash the interior with a suitable disinfectant and allow it to dry completely before refilling. When filling the bin, distribute the grain evenly to minimize fines and foreign material. Fines tend to accumulate in the center of the bin and create pockets of poor airflow that are prone to mold. A grain spreader can help distribute fines more evenly. If you do not have a spreader, consider running the bin partially full and leveling the grain by hand. Temperature monitoring is important for whole grain storage. A temperature cable or probe system allows you to detect hot spots before they become mold problems. Grain that is heating indicates excessive moisture and microbial activity. If you detect a hot spot, you may need to run air through the grain or move the grain to another bin to cool it. ### Finished Feed Storage Finished feed, whether meal or pelleted, is more susceptible to spoilage than whole grain because grinding increases surface area and exposes nutrients that molds can use. For this reason, finished feed should be stored for the shortest time possible. Feed bins for finished feed should be clean, dry, and protected from the elements. The bin should have a tight-fitting lid that keeps out rain and birds. The bottom should be easy to access so you can clean out old feed between loads. Some producers find that bins with steep hopper bottoms and smooth interior walls are easier to keep clean than flat-bottom bins. The location of feed bins matters. Place them in a shaded area to keep the feed cooler during summer months. Avoid placing bins where they will be exposed to direct afternoon sun, which can heat the feed and create condensation when temperatures drop at night. Bagged feed requires different handling. Store bags on pallets off the floor to keep them dry. Leave space between rows and away from walls to allow air circulation. Do not stack bags so high that they are difficult to inspect or move. Use the oldest bags first and never store bagged feed for more than a few months. ### Feed Delivery Systems The augers, conveyors, and feeders that move feed from storage to pigs are often overlooked sources of contamination. Feed dust and fines accumulate in these systems and can become moldy over time. This moldy material can then contaminate fresh feed as it passes through. Inspect augers and conveyors regularly for buildup. Clean them according to the manufacturer recommendations, especially when switching feed types or after a contamination event. Feeders in the barn should be checked daily for stale or moldy feed. Adjust feeder settings to minimize waste and prevent feed from sitting in the feeder for extended periods. ## Step-by-Step Guide to Preventing Mold in Swine Feed Prevention is the most cost-effective approach to mycotoxin management. Follow these steps to establish a solid prevention program on your farm. ### Step 1: Source Quality Ingredients Start with good ingredients. Buy grain from reputable suppliers who can provide information about moisture content at harvest and storage conditions. Ask about field conditions during the growing season, as drought-stressed or insect-damaged crops have higher mycotoxin risk. When receiving grain, check moisture content before accepting the load. Reject loads that are too wet. A moisture meter is an essential tool for this purpose. Calibrate it regularly according to the manufacturer instructions. ### Step 2: Dry Grain Properly If you harvest your own grain, dry it promptly after harvest. The target moisture content depends on the storage duration. For grain stored up to six months, aim for 14 percent moisture or less. For grain stored longer than six months, aim for 13 percent or less. For finished feed, the target is 12 percent or less. Dry grain with properly calibrated equipment. Over-drying wastes energy and can cause kernel damage. Under-drying creates conditions for mold growth. Test moisture content at several points in the bin after drying to ensure uniform moisture. ### Step 3: Clean Storage Facilities Before Each Use Make cleaning a standard procedure before every bin filling. Remove all old feed and debris. Scrape walls and floors to remove caked material. Inspect for signs of previous mold growth, insect infestations, or rodent activity. Repair any structural damage that could let in moisture or pests. For bins that have had mold problems, consider washing with a disinfectant approved for feed contact surfaces. Rinse thoroughly and allow complete drying before refilling. Never mix new feed with old feed that has been in the bin for an extended period. ### Step 4: Control Moisture Throughout the System Moisture can enter the feed system at many points. Check bin lids and seals regularly to ensure they are watertight. Inspect roofs for leaks after heavy rains. Make sure that drainage around bins directs water away from the base. In humid climates, be aware that ground feed can absorb moisture from the air. This is more of a problem in open storage or when feed is held in bins with poor seals. Some producers use moisture barriers or desiccants in extreme conditions, but the most effective approach is to use feed quickly and not store ground feed for long periods. ### Step 5: Manage Temperature Keep feed cool to slow mold growth. In summer, shade feed bins and provide ventilation around storage areas. In winter, be aware that temperature fluctuations can cause condensation inside bins. This condensation can wet the surface layer of feed and create localized mold problems. Insulated bins or bins with ventilation systems can help reduce condensation problems. Some producers use aeration systems to move air through grain and equalize temperatures. The goal is to keep the grain temperature as close to the average ambient temperature as possible, avoiding wide swings. ### Step 6: Practice First-In, First-Out Rotation Use older feed before newer feed. This seems simple, but it requires discipline and organization. Clearly label bins and bags with delivery dates. Keep a record of what is in each bin and when it was filled. Use a rotation system that ensures no feed sits in storage longer than necessary. For finished feed, the goal is to use it within one to two weeks of grinding or delivery. For whole grain, the goal is to use it within the crop year. If you have feed that has been in storage for an extended period, test it before feeding, even if it looks fine. ### Step 7: Inspect Feed Regularly Visual inspection is the first line of defense. Check feed at every delivery and before every feeding. Look for visible mold, which can appear as white, gray, green, or black growth on the surface of grain or feed. Also look for clumping, caking, or an unusual odor. Fresh feed should smell clean and slightly sweet. A musty, sour, or fermented odor indicates spoilage. Use a flashlight to inspect the corners and bottom of bins where mold is more likely to develop. If you see mold, do not feed the affected material to pigs. Remove the moldy feed and clean the bin before adding fresh feed. ### Step 8: Control Pests Insects and rodents can damage feed and create conditions that promote mold growth. Insects can also carry mold spores from contaminated areas to clean feed. Implement a pest control program that includes regular monitoring, exclusion, and treatment when needed. Keep the area around feed storage clean and free of spilled feed. This reduces attractants for rodents and insects. Use bait stations and traps according to label directions. Seal holes and gaps in buildings and bins to prevent rodent entry. ### Step 9: Use Feed Additives Wisely There are feed additives marketed as mold inhibitors and mycotoxin binders. Mold inhibitors, such as organic acids and propionic acid products, can help prevent mold growth in feed. They are most useful when feed will be stored for extended periods or when moisture control is difficult. Mycotoxin binders and detoxifiers are products that claim to reduce the absorption of mycotoxins in the digestive tract. Some products, such as certain clays and yeast cell wall derivatives, have shown effectiveness for specific mycotoxins. However, results vary, and these products do not eliminate the need for good storage practices. Work with your veterinarian or nutritionist to determine if these products are appropriate for your situation. ### Step 10: Test Feed When Risk Is High Testing is an essential part of a comprehensive mycotoxin management program. You cannot always see or smell mycotoxins, and the only way to know for sure what is in your feed is to test it. Test feed when any of the following conditions apply: - You see visible mold in the feed or storage bin. - Feed has been exposed to moisture from a leak or flood. - Grain was harvested under stressful conditions such as drought or excessive rain. - Pigs show unexplained reductions in feed intake, growth, or reproductive performance. - You are using a new feed supplier or a new crop year of grain. - Feed has been stored for an extended period. ## How to Test Feed for Mycotoxins Mycotoxin testing has become more accessible and affordable in recent years. Several types of tests are available, ranging from quick on-farm tests to comprehensive laboratory analysis. ### On-Farm Test Kits Rapid test kits allow you to test feed on the farm and get results within minutes. These kits use lateral flow technology, similar to a pregnancy test, and can detect specific mycotoxins at certain levels. They are useful for screening feed and making quick decisions, but they have limitations. On-farm kits are less accurate than laboratory tests and may give false positives or false negatives. They are also limited to the specific mycotoxins they are designed to detect. If you are concerned about multiple mycotoxins, you may need to run multiple tests or use a laboratory that can test for a panel of toxins. Despite these limitations, on-farm kits can be a valuable part of a monitoring program. They allow you to check feed quickly when you suspect a problem, and they can help you decide whether to send samples to a laboratory for more comprehensive analysis. ### Laboratory Testing Laboratory testing provides more accurate and comprehensive results. You can request testing for individual mycotoxins or for a panel that covers the most common toxins affecting swine. Laboratories use methods such as high-performance liquid chromatography (HPLC) or enzyme-linked immunosorbent assay (ELISA) to detect and quantify mycotoxins. The cost of laboratory testing varies depending on the number of toxins tested and the laboratory. A single mycotoxin test may cost $50 to $100, while a comprehensive panel may cost $150 to $300. This cost is small compared with the potential losses from feeding contaminated feed. ### How to Collect a Representative Sample The accuracy of any test depends on the quality of the sample. Mycotoxins are not distributed evenly through feed. One part of a bin may be heavily contaminated while another part is clean. A single handful of feed is not representative of the whole bin. To get a representative sample, collect multiple subsamples from different locations in the bin or lot. Use a grain probe to sample the depth of the bin, not just the surface. Collect at least 5 to 10 subsamples from different locations and combine them into a single composite sample. Mix the composite sample thoroughly and then take a smaller subsample for testing. For bagged feed, sample from several bags, not just one. For finished feed, sample from the feeder or the delivery system, not just the storage bin. Label the sample clearly with the date, the feed type, the source, and the location. Keep a record of the sample for your files. If you are testing because of a herd health problem, also record which group of pigs received the feed and when they were fed. ### Interpreting Test Results Test results report mycotoxin levels in parts per million (ppm) or parts per billion (ppb). These numbers mean little without context. The significance of a particular level depends on the toxin, the age and type of pig, and the duration of exposure. Your veterinarian or extension agent can help you interpret test results and establish action thresholds for your operation. The following general guidance is based on published recommendations and common industry practice. For aflatoxins, levels below 20 ppb are generally considered acceptable for finishing pigs. Levels above 200 ppb can cause reduced growth and liver damage. Breeding stock should be fed feed with lower levels, ideally below 100 ppb. For DON, pigs are the most sensitive species. Levels below 1 ppm are generally considered safe for most pigs. Levels of 1 to 5 ppm can cause reduced feed intake and reduced growth. Levels above 5 ppm can cause feed refusal and vomiting. Breeding stock should be fed feed with less than 1 ppm DON. For zearalenone, the concern is reproductive effects. Levels below 1 ppm are generally considered safe for breeding stock, though some sources recommend lower thresholds for young gilts. Levels of 1 to 3 ppm can cause vulvar swelling and reduced fertility. Higher levels can cause more severe reproductive problems. These are general guidelines, not absolute thresholds. The actual impact on your herd depends on many factors, including the presence of other toxins, the health status of the pigs, and the duration of exposure. Work with your veterinarian to establish thresholds for your specific operation. ## Feeding Contaminated Feed: Options and Precautions When test results show that feed is contaminated, you have several options. The best option depends on the toxin, the level of contamination, and the type of pigs you are feeding. ### Dilution Dilution involves mixing contaminated feed with clean feed to reduce the toxin level below the action threshold. This is a common practice for moderate contamination. The key is to know the toxin level in the contaminated feed and the clean feed, then calculate the correct ratio to achieve a safe final concentration. For example, if you have feed with 4 ppm DON and you want to feed a diet with no more than 1 ppm DON, you would mix one part contaminated feed with three parts clean feed. This assumes the clean feed has no detectable DON. If the clean feed has some background contamination, you need to account for that in your calculation. Dilution is not appropriate for highly contaminated feed or for toxins that are toxic at very low levels. It also requires that you have clean feed available for mixing. Work with your nutritionist to ensure that dilution does not compromise the nutrient content of the final diet. ### Feeding to Less Sensitive Animals Some mycotoxins affect certain classes of pigs more than others. For example, finishing pigs are less sensitive to zearalenone than breeding stock. If you have feed contaminated with zearalenone, you might be able to feed it to finishing pigs while protecting breeding stock. However, this approach requires caution. Even if a toxin does not cause obvious clinical signs in a particular class of pig, it can still cause immune suppression and reduced performance. The economic impact may be subtle but real. This option should only be considered for mild contamination and should be discussed with your veterinarian. ### Using Binders and Detoxifiers Mycotoxin binders are feed additives that bind to toxins in the digestive tract and reduce their absorption. The most common binders are aluminosilicates, such as bentonite and hydrated sodium calcium aluminosilicate (HSCAS). These products are most effective against aflatoxins and less effective against other mycotoxins. Other products, such as yeast cell wall derivatives and enzymes, claim to degrade or bind specific mycotoxins. The effectiveness of these products varies, and not all products are supported by solid research. If you are considering a binder, ask your veterinarian or nutritionist for products with published efficacy data. Binders are not a substitute for good feed management. They should be used as a temporary measure to manage contaminated feed, not as a routine additive to allow poor storage practices. ### Discarding Contaminated Feed In some cases, the safest and most economical option is to discard the contaminated feed. This is the right choice when toxin levels are high, when the feed is severely moldy, or when the feed is intended for breeding stock or young pigs. Discarding feed has a cost, but that cost may be less than the cost of reduced performance, illness, or death in the herd. Consider the value of the feed, the cost of testing, the potential losses from feeding, and the risk to the herd when making this decision. ### Handling Severely Contaminated Feed If you must handle severely moldy feed, take precautions to protect yourself and your employees. Mold spores can cause respiratory problems when inhaled. Wear a dust mask or respirator rated for particulate protection. Wear gloves when handling moldy feed. Avoid creating dust clouds when moving or disposing of contaminated feed. Do not compost moldy feed or spread it on fields where livestock graze. Some mycotoxins persist in the environment and can contaminate soil and water. Check with your local agricultural extension office for guidance on disposing of contaminated feed in your area. ## Common Mistakes in Swine Feed Storage Even experienced producers make mistakes in feed storage. Recognizing these common errors can help you avoid them. ### Storing Feed Too Long The most common mistake is storing feed longer than necessary. Whole grain can be stored for months under good conditions, but finished feed should be used within days or weeks. Some producers grind large quantities of feed to save labor, but this increases the risk of spoilage. The better approach is to grind feed more frequently in smaller batches. ### Ignoring the Corners and Bottom of Bins Mold often starts in the corners and bottom of bins where old feed accumulates and moisture collects. These areas are easy to overlook during inspection. Make a habit of checking the bottom of bins through access ports and cleaning out old feed before adding new feed. ### Relying on Visual Inspection Alone Visible mold is a sign that contamination is already established. By the time you see mold, mycotoxins may already be present at harmful levels. Visual inspection is important, but it is not sufficient. Use your senses of smell and touch as well. Musty odors and caked or sticky feed are warning signs even when visible mold is not obvious. ### Not Testing Feed Many producers skip testing because of the cost or because they assume their feed is fine. This is a gamble. Mycotoxin contamination can occur even in feed that looks and smells normal. Testing is especially important when you are using a new crop year of grain, when field conditions were stressful, or when pigs show unexplained performance problems. ### Mixing New Feed with Old Feed Adding new feed on top of old feed creates a situation where the old feed sits in the bin for an extended period. This old feed can become moldy and contaminate the new feed. Always empty bins completely before adding new feed, or at least clean out the old feed so it is used first. ### Overlooking Moisture Sources A small leak in a bin roof or a loose lid can introduce enough moisture to cause mold problems. Producers sometimes overlook these issues because they are not obvious during dry weather. Inspect storage facilities regularly, especially after storms and during periods of high humidity. ### Neglecting Pest Control Rodents and insects damage feed and create conditions for mold growth. They also carry mold spores from one area to another. A pest control program is an essential part of feed storage management, not an optional extra. ### Using Binders as a Substitute for Good Management Some producers add mycotoxin binders to all feed as insurance against contamination. While this can be part of a management program, it does not address the root causes of contamination. Binders are not effective against all mycotoxins, and they add cost to every ton of feed. The better approach is to focus on prevention through good storage practices, and use binders selectively when you know you have a contamination problem. ## Monitoring and Recordkeeping A successful feed storage program requires ongoing monitoring and careful recordkeeping. These practices help you spot problems early, make informed decisions, and document your management for audits and certifications. ### Daily Monitoring Check feed storage areas daily as part of your regular farm routine. Look for signs of damage to bins and roofs. Check that lids are secure. Look for spilled feed around bins that could attract pests. Notice any unusual odors coming from bins or feeders. In the barn, check feeders daily for stale or moldy feed. Pigs will often refuse moldy feed, leaving it in the feeder while eating around it. If you see feed accumulation in feeders, investigate the cause. ### Weekly Monitoring Once a week, do a more thorough inspection of feed storage areas. Check the condition of grain in bins using a probe or by examining samples from access ports. Look for signs of heating, such as condensation on bin walls or a musty smell when you open the bin. Check temperature readings if you have a grain temperature monitoring system. A rise in temperature indicates microbial activity. Investigate any changes and take corrective action if needed. ### Monthly Monitoring Once a month, review your feed inventory and usage. Calculate how much feed you have on hand and how long it will last at current usage rates. Identify any feed that has been in storage for an extended period and plan to use it soon. Check pest control devices and replenish bait stations as needed. Inspect the area around feed storage for signs of rodent activity, such as droppings, burrows, or gnaw marks. ### Recordkeeping Keep detailed records of all feed-related activities. At a minimum, record the following: - Feed deliveries, including date, source, ingredient, and moisture content - Feed inventory by bin or storage location - Dates when bins were cleaned and inspected - Results of any mycotoxin tests, including the laboratory, test method, and results - Any contamination events, including the cause, the response, and the outcome - Feed usage by group of pigs, including dates and amounts fed - Any health or performance problems that could be related to feed quality These records serve multiple purposes. They help you identify patterns and prevent future problems. They provide documentation for insurance claims or regulatory inquiries. They also demonstrate to buyers and auditors that you are managing feed quality responsibly. ### Using Records to Improve Management Review your records regularly to identify areas for improvement. Are certain bins more prone to problems than others? Do problems occur more often at certain times of year? Are certain suppliers more reliable than others? Use this information to adjust your management practices. For example, if you notice that feed stored in bins exposed to afternoon sun has more moisture problems in summer, consider relocating those bins or adding shade. If you notice that a particular supplier consistently delivers grain with high moisture content, consider switching suppliers or testing every load from that source. ## When to Call a Veterinarian or Extension Agent Knowing when to seek professional help is an important part of mycotoxin management. Some situations require immediate attention from a veterinarian, while others can be handled with guidance from an extension agent. ### Call Your Veterinarian When - Pigs show acute signs such as vomiting, diarrhea, or sudden death. - Multiple pigs are affected at the same time with similar signs. - Feed refusal is severe, with pigs eating less than 50 percent of their expected intake. - Reproductive problems occur, such as abortions, stillbirths, or swollen vulvas in gilts. - Pigs show signs of respiratory distress, especially after eating. - You suspect that aflatoxin levels are high enough to cause liver damage or acute illness. Your veterinarian can help you diagnose the problem, rule out infectious diseases, and develop a treatment and management plan. They can also help you interpret feed test results and determine safe feeding levels. ### Call Your Extension Agent When - You need help developing a feed storage plan or improving your current system. - You have questions about testing methods or interpreting test results. - You need guidance on disposal options for contaminated feed. - You want information about mycotoxin binders or other feed additives. - You are considering new storage equipment and want advice on specifications. - You want to understand regional risk factors for mycotoxin contamination. Extension agents have access to resources and expertise that can help you make informed decisions. They can also connect you with specialists in grain storage, animal nutrition, and agricultural engineering. ### When to Test Feed Before Calling In many situations, you can gather useful information before calling for help. If you suspect a mycotoxin problem, collect a feed sample and submit it for testing. The test results will help your veterinarian or extension agent give you specific advice rather than general guidance. Take note of the signs you are seeing in the pigs, including which groups are affected, when the signs started, and how many pigs are affected. This information will help your veterinarian make a diagnosis and develop a response plan. ## Mycotoxin Management in Different Production Stages Different classes of pigs have different sensitivities to mycotoxins, and the management approach should reflect these differences. ### Nursery Pigs Nursery pigs are the most sensitive to mycotoxins. Their immune systems are still developing, and they are already stressed by weaning and moving. Mycotoxin exposure in the nursery can cause poor growth, increased disease susceptibility, and higher mortality. For nursery pigs, use the highest quality feed ingredients available. Test all feed before feeding, especially when using new crop grain. Keep feed fresh by using small batches and cleaning feeders regularly. Consider using mycotoxin binders in nursery diets if you have any reason to suspect contamination. ### Growing and Finishing Pigs Growing and finishing pigs are more tolerant of mycotoxins than nursery pigs, but they are still affected. The main economic impact is reduced feed intake and growth rate. This translates into more days to market and higher feed costs per pound of gain. For growing and finishing pigs, monitor feed intake closely. A sudden drop in intake can be an early sign of mycotoxin contamination. Check feeders daily and investigate any changes in eating behavior. Test feed if you see a pattern of reduced intake across multiple pens. ### Breeding Stock Breeding stock requires special attention because mycotoxins can affect reproduction. Zearalenone is the main concern, as it can cause false estrus, reduced conception rates, and increased embryonic mortality. Aflatoxins and DON can also affect reproductive performance through their effects on feed intake and immune function. For breeding stock, use the highest quality feed and test regularly. Keep breeding stock on feed that is known to be safe. If you have contaminated feed, do not feed it to breeding animals, even if the contamination level seems low. The cost of a reproductive failure is far greater than the cost of discarding contaminated feed. ### Boars Boars are often overlooked in mycotoxin management, but they are also affected. Zearalenone can reduce libido and semen quality. Other mycotoxins can reduce overall health and fertility. Keep boars on high-quality feed and monitor their condition and breeding performance. ## Regional and Seasonal Considerations Mycotoxin risk varies by region and by season. Understanding your local risk factors can help you plan your management program. ### Field Conditions The weather during the growing season has a major influence on mycotoxin contamination. Drought stress during grain fill increases the risk of aflatoxin contamination in corn. Cool, wet conditions during flowering and grain fill increase the risk of Fusarium toxins like DON and zearalenone. Insect damage provides entry points for mold infection. If your region experienced stressful growing conditions, plan to test the new crop before feeding. Do not assume that because last year was fine, this year will be fine too. ### Harvest Conditions Delayed harvest increases the risk of mold contamination in the field. Grain that stands in the field through wet weather can develop mold before it is even harvested. Harvest promptly when grain is mature and dry. ### Storage Season The time of year affects storage conditions. In summer, heat and humidity increase the risk of mold growth. In winter, temperature fluctuations can cause condensation in bins. Each season requires different management attention. In summer, focus on keeping feed cool and dry. Shade bins, ventilate storage areas, and use feed quickly. In winter, focus on preventing condensation. Insulate bins, aerate grain to equalize temperatures, and check for ice buildup in bins and augers. ### Regional Testing Programs Some regions have mycotoxin testing programs or monitoring networks that track contamination levels in the local grain supply. Check with your extension agent to see if such programs exist in your area. This information can help you anticipate problems before they affect your herd. ## Building a Mycotoxin Management Plan A written mycotoxin management plan helps ensure that everyone on the farm knows what to do and when. The plan should be specific to your operation and should cover prevention, monitoring, and response. ### Elements of a Management Plan Your plan should include the following elements: - A description of your feed storage system, including bins, equipment, and capacities - Standard procedures for receiving, storing, and using feed - Cleaning and maintenance schedules for storage facilities and equipment - Monitoring procedures, including what to check, how often, and who is responsible - Testing protocols, including when to test and how to collect samples - Action thresholds for specific mycotoxins for each class of pigs - Response procedures for contamination events, including who to contact and what steps to take - Recordkeeping requirements and responsibilities - Training requirements for employees ### Implementing the Plan A plan is only useful if it is followed. Train all employees on the plan and their responsibilities. Post key procedures in feed storage areas and barns. Review the plan regularly and update it as conditions change. Conduct regular audits of your feed storage practices to ensure compliance with the plan. If you find gaps, address them promptly. The goal is to make feed storage and mycotoxin management a routine part of daily farm operations, not an afterthought. ## The Role of Feed Millers and Suppliers If you purchase finished feed from a commercial mill, your role in mycotoxin management is different but still important. You rely on the miller to source quality ingredients and follow good manufacturing practices. However, you still need to store the feed properly on your farm and monitor its condition. Ask your feed supplier about their mycotoxin testing program. Many commercial mills test incoming ingredients and finished feed for common mycotoxins. Ask to see their testing results or their quality assurance program. A reputable supplier will be transparent about their quality control practices. When you receive feed from a commercial mill, inspect it for quality. Check the condition of the bags or the bulk delivery. Look for signs of moisture damage, mold, or pest contamination. If you have concerns, reject the delivery and contact the supplier immediately. ## The Economics of Feed Storage Investment Investing in proper feed storage infrastructure can seem expensive, but the return on investment is often substantial. Consider the following calculations. A mycotoxin outbreak can reduce growth rates by 5 to 10 percent and increase feed conversion by 5 percent or more. For a farm marketing 5,000 pigs per year, this could mean an additional 2,500 to 5,000 pounds of feed per year and an additional 5 to 10 days to market. At current feed and pig prices, this could easily represent tens of thousands of dollars in lost revenue. The cost of a moisture meter, a grain probe, and a basic testing program is a few hundred to a few thousand dollars per year. The cost of bin improvements, such as better seals, ventilation, or temperature monitoring, varies widely but is often recovered within one or two years if it prevents even one contamination event. The bottom line is that feed storage and mycotoxin management is not an expense. It is an investment in the health and productivity of your herd. The producers who take this seriously are the ones who consistently achieve better feed efficiency and lower mortality. ## Frequently Asked Questions ### How long can I safely store swine feed? Whole grain stored under good conditions, with moisture below 13 percent and protection from moisture and pests, can be stored for several months to a year. Finished feed, whether meal or pellets, should be used within one to two weeks of grinding or delivery. The longer feed sits in storage, the greater the risk of mold growth and mycotoxin production. Use a first-in, first-out rotation system and never mix new feed with old feed that has been sitting in a bin. ### What moisture level is safe for storing grain for pig feed? For grain stored up to six months, aim for 14 percent moisture or less. For grain stored longer than six months, aim for 13 percent or less. Finished feed should be at 12 percent moisture or less. These targets help prevent the conditions that allow mold growth. Test moisture content at several points in the bin after filling, because moisture can vary within a bin. ### Can I feed moldy grain to pigs if I mix it with clean feed? Dilution can reduce the concentration of mycotoxins in the final diet, but it is only appropriate for moderate contamination and only when you know the toxin levels. Test the contaminated feed and the clean feed, then calculate the correct ratio to achieve a safe final concentration. Do not feed severely moldy feed to any pigs, and never feed contaminated feed to breeding stock or nursery pigs. Work with your veterinarian or nutritionist before using dilution as a strategy. ### What are the signs that my pigs are being affected by mycotoxins? The most common signs are reduced feed intake, reduced growth rate, and poorer feed conversion. Pigs may also show vomiting, diarrhea, or signs of immune suppression such as increased respiratory disease. In breeding stock, look for swollen vulvas in gilts, irregular estrus cycles, reduced conception rates, and small litters. If you see these signs, test your feed and contact your veterinarian. ### How much does mycotoxin testing cost? On-farm test kits cost $10 to $30 per test and provide results in minutes. Laboratory testing costs $50 to $100 for a single mycotoxin and $150 to $300 for a comprehensive panel covering multiple toxins. The cost of testing is small compared with the potential losses from feeding contaminated feed. If you suspect a problem, testing is a wise investment. ### Do mycotoxin binders really work? Some mycotoxin binders are effective for specific toxins. Aluminosilicate clays are most effective against aflatoxins. Yeast cell wall derivatives and other products may bind other toxins, but the evidence for their effectiveness varies. No binder is effective against all mycotoxins, and binders do not eliminate the need for good storage practices. Ask your veterinarian or nutritionist for products with published efficacy data. ### Can mycotoxins survive feed processing such as pelleting? Yes. Mycotoxins are heat-stable compounds that survive pelleting, extrusion, and most feed processing methods. Pelleting may kill mold spores, but the toxins that have already been produced remain in the feed. This means that processing does not solve a mycotoxin problem. The only way to reduce toxin levels is to dilute contaminated feed with clean feed or discard the contaminated feed. ### How do I dispose of contaminated feed safely? The best disposal method depends on the level of contamination and local regulations. Options include landfilling, deep burial, or incineration. Do not compost moldy feed or spread it on fields where animals graze, because some mycotoxins persist in the environment. Check with your local extension office or environmental agency for approved disposal methods in your area. Wear a dust mask and gloves when handling moldy feed to protect yourself from mold spores. ## Related Farming Guides This section will be populated with links to related farming guides on swine production, feed management, and herd health topics. ## Related Clinical & Scientific Guides * [Pig Enrichment Programs and Behavior Monitoring](/knowledge/animal-farming/swine/pig-enrichment-programs-and-behavior-monitoring) * [Swine Handling Facility Design for Safe Pig Movement](/knowledge/animal-farming/swine/swine-handling-facility-design-safe-pig-movement) * [Swine Feeding Management for Grow-Finish Pigs](/knowledge/animal-farming/swine/swine-feeding-management-for-grow-finish-pigs) ## References - National Pork Board: https://www.pork.org/ - USDA APHIS Swine Health: https://www.aphis.usda.gov/livestock-poultry-disease/swine - FAO Pig Production: https://www.fao.org/pig-production-and-products/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.