# Swine Feed Ingredient Substitution and Alternative Feeds ## Key Takeaways - Ingredient substitution must be based on matching critical nutrient values (metabolizable energy, crude protein, lysine, calcium, and available phosphorus) rather than a pound-for-pound replacement, as nutrient densities vary significantly. - Synthetic amino acids, particularly L-lysine, L-threonine, DL-methionine, and L-tryptophan, are crucial for balancing diets when using alternative protein sources that may be deficient in these essential nutrients. - High-fiber ingredients like distillers grains and wheat middlings should be limited to gestation diets or a maximum of 10-20% of grower-finisher rations to avoid reducing energy density and negatively impacting feed efficiency. - Gradual introduction of new feed formulations over 3 to 5 days is essential to minimize feed refusal and digestive upset, with initial inclusion rates of alternative ingredients typically starting at 5-10% and increased only after monitoring feed intake and stool consistency. - Accurate recordkeeping of ingredient costs, inclusion rates, and pig performance metrics (average daily gain, feed conversion) is vital to verify actual cost savings per pound of gain, not just per ton of feed. - Alternative ingredients, especially wet byproducts and bakery meal, require testing for moisture and nutrient content before formulation, and careful monitoring for mycotoxin contamination and rancidity due to their variable nature and storage susceptibility. --- Feed accounts for the largest single expense in most swine operations, often consuming 60 to 70 percent of total production costs. When corn and soybean meal prices spike, or when supply chains tighten, producers need practical options for keeping rations balanced without sacrificing pig performance. This guide covers the most reliable swine feed ingredients alternatives, explains how to substitute ingredients safely, and provides step-by-step methods for ration reformulation. It is written for independent hog farmers, contract growers, feed mill managers, and anyone who formulates or adjusts swine diets and needs clear guidance on alternative [pig feed ingredients](/knowledge/animal-farming/swine/pig-feed-ingredients-grains-protein-supplements). ## At a Glance - Substitute on a nutrient basis, never on a pound-for-pound basis. Different ingredients have different moisture, fiber, and protein levels. - The five critical values to match are metabolizable energy, crude protein, lysine, calcium, and available phosphorus. - Start with small inclusion rates, typically 5 to 10 percent of the diet, and increase only after observing feed intake and stool consistency. - Add synthetic amino acids when using alternative protein sources to keep lysine, threonine, methionine, and tryptophan balanced. - Limit high-fiber ingredients like distillers grains and wheat middlings to gestation diets or to 10 to 20 percent of grower-finisher rations. - Test alternative ingredients for moisture and nutrient content before formulating, especially wet byproducts and bakery meal. - Introduce diet changes gradually over 3 to 5 days to reduce feed refusal and digestive upset. - Keep accurate records of ingredient costs, inclusion rates, and pig performance so you can verify that substitutions actually save money. ## Why [Swine Feed Ingredient Substitution](/knowledge/animal-farming/swine/swine-feed-ingredient-substitution-cost-saving-alternatives) Matters The economic pressure to find cheaper feed ingredients never disappears. Corn and soybean meal prices move with global markets, weather events, and policy decisions. A drought in the Corn Belt or an export disruption can change ration costs by 20 to 30 percent within weeks. Producers who understand swine feed substitution can respond quickly without sacrificing herd health or growth rates. There are also supply-side reasons to consider alternative [pig feed ingredients](/knowledge/animal-farming/swine/pig-feed-ingredients-grains-protein-supplements). Regional feed mills may run short of a particular ingredient, especially during harvest transitions or after transportation disruptions. Some producers have access to local byproducts like bakery waste, distillers grains, or culled vegetables that cost less than traditional grains. In other cases, a producer may want to reduce reliance on imported soybean meal and use locally grown field peas, canola meal, or sunflower meal instead. Beyond cost, there are management benefits. Rotating feed ingredients can reduce the risk of mycotoxin exposure from a single contaminated grain source. It can also improve gut health in some herds when fiber sources are added thoughtfully. However, every substitution carries risk. Pigs are sensitive to sudden diet changes, and improperly balanced rations can cause reduced intake, slower gains, loose stools, or even nutritional deficiencies that show up weeks later. ## Understanding Nutrient Requirements Before You Substitute You cannot substitute feed ingredients successfully without knowing what the pig needs. Nutrient requirements vary by stage of production, and they are expressed in specific units that must match the values on your ingredient analysis. ### Key Nutrients to Balance Metabolizable energy (ME) is the energy available to the pig after digestion and metabolic losses. It is expressed in kilocalories per pound or megacalories per pound of feed. Corn supplies about 1,540 kcal ME per pound. Alternative energy sources like wheat, barley, and bakery meal will have different values, and you must adjust inclusion rates accordingly. Crude protein is the total nitrogen content of the feed multiplied by 6.25. It is a rough measure because not all protein is digestible. What matters more is the amino acid profile, particularly the essential amino acids the pig cannot synthesize. Lysine is almost always the first limiting amino acid in swine diets, meaning it is the one most likely to be deficient. Threonine, methionine, and tryptophan are the next most important. Calcium and phosphorus work together for bone development and metabolic function. The ratio matters. Most swine rations target a calcium to available phosphorus ratio between 1.5:1 and 2:1. Phytate-bound phosphorus in grains and oilseed meals is poorly digested, so producers add phytase enzyme or use ingredients with higher available phosphorus. Fiber is often overlooked but critical. Pigs have a limited ability to digest fiber, especially young pigs. High fiber levels reduce energy density and can cause loose manure. Gestating sows tolerate more fiber than growing pigs, and some fiber in gestation diets improves satiety and reduces stereotypies like bar biting. ### How to Read an Ingredient Analysis Before you substitute anything, get a current nutrient analysis of both the ingredient you are replacing and the ingredient you plan to use. Feed mills provide guaranteed analyses on their ingredient sheets. If you buy from a local supplier, ask for a certificate of analysis. For wet byproducts, moisture content varies enormously, and you must adjust all nutrient values to a dry matter basis or to the as-fed basis you will actually mix. The most useful values for formulation are dry matter, crude protein, lysine, methionine, threonine, tryptophan, calcium, total phosphorus, available phosphorus, and metabolizable energy. Some analysis sheets also list crude fiber, neutral detergent fiber, and fat. For byproducts like distillers grains, check for sulfur content, because high sulfur can cause polioencephalomalacia in pigs. ## Common Swine Feed Ingredients and Their Alternatives ### Energy Sources Corn is the standard energy source in most US swine diets. It is palatable, low in fiber, and provides consistent energy. The most common swine feed ingredients alternatives for corn are wheat, barley, grain sorghum (milo), bakery meal, and fat or oil supplements. Wheat is an excellent substitute for corn in many regions. It has slightly higher crude protein, about 12 to 14 percent versus 8 to 9 percent for corn, and similar metabolizable energy. Wheat can replace all of the corn in grower-finisher diets if it is ground to the correct particle size. The main caution is that wheat contains more soluble fiber, so diets with high wheat inclusion may need a commercial enzyme product to improve digestibility. Barley has about 90 percent of the energy value of corn and higher fiber. It works well in gestation diets and can replace up to half of the grain in grower diets. For finisher pigs, keep barley at 30 percent or less to avoid reducing feed efficiency. Hulless barley has better energy value than hulled barley. Grain sorghum is a drought-tolerant crop that grows well in the southern Plains. It has about 95 percent of the energy of corn and slightly less lysine. Sorghum should be ground more finely than corn because its kernel is harder. Tannin content varies by variety, and high-tannin sorghum is less palatable. Use low-tannin varieties for swine. Bakery meal, also called bakery waste or cookie meal, is a byproduct of bread, cookie, cracker, and pasta production. It is high in energy and fat, often containing 10 to 15 percent fat, and it is highly palatable to pigs. The nutrient profile varies by source, so test each load. Bakery meal can replace 20 to 50 percent of the grain in grower-finisher diets. Store it carefully because its high fat content makes it prone to rancidity, especially in warm weather. Fat and oil supplements, including choice white grease, poultry fat, and vegetable oils, add concentrated energy to diets. They are not complete substitutes for grain, but they can offset the lower energy of high-fiber ingredients. The industry standard is to add fat at 2 to 6 percent of the diet. Each 1 percent added fat increases diet energy by roughly 15 to 18 kcal ME per pound, but it also increases the risk of soft fat in carcasses if inclusion is too high. ### Protein Sources Soybean meal is the gold standard protein source for swine because of its excellent amino acid profile and digestibility. When it becomes too expensive, producers look for alternative pig feed ingredients to replace part or all of it. Canola meal is the most common soybean meal substitute in many regions. It has about 36 to 38 percent crude protein, slightly less than soybean meal at 44 to 48 percent. Canola meal is lower in lysine but higher in methionine and cysteine. It also contains glucosinolates, which can reduce feed intake at high inclusion rates. Limit canola meal to 10 to 15 percent of grower-finisher diets and 20 percent of gestation diets. Distillers dried grains with solubles (DDGS) is a byproduct of ethanol production. It has about 27 to 30 percent crude protein and is high in phosphorus, fat, and fiber. DDGS is a popular swine feed ingredient because it is usually cheaper than corn and soybean meal on a per-ton basis. However, it is not a direct substitute for either. A typical recommendation is to include DDGS at 10 to 20 percent of grower-finisher diets and up to 40 percent of gestation diets. At higher levels, the fat content can cause soft carcass fat, and the high fiber can reduce feed efficiency. Field peas, also called dry peas or feed peas, are an excellent protein and energy source. They contain about 22 to 24 percent crude protein and are highly digestible. Field peas have low levels of antinutritional factors and are very palatable. They can replace up to 30 percent of soybean meal in grower-finisher diets without added synthetic amino acids, and more if lysine is supplemented. Sunflower meal is a byproduct of sunflower oil extraction. It has about 28 to 34 percent crude protein but is high in fiber, especially if the hulls are not removed. Use dehulled sunflower meal at 10 to 15 percent of the diet. The high fiber content limits its use in young pigs. Peanut meal is high in protein, about 45 to 50 percent, but it is variable in quality and can contain aflatoxins if not stored properly. Test every load for aflatoxin before feeding. Peanut meal can replace up to 20 percent of soybean meal in grower diets. Cottonseed meal is a protein source that requires caution. It contains gossypol, a toxic compound that can cause heart and liver damage in pigs. Use only glandless cottonseed meal, and limit inclusion to 5 percent of the diet. It is generally not recommended for breeding stock. Synthetic amino acids, particularly L-lysine, L-threonine, DL-methionine, and L-tryptophan, are not feed ingredients in the traditional sense, but they are essential tools for swine feed substitution. When you replace soybean meal with lower-protein ingredients, you can add synthetic lysine to bring the diet back into balance at a lower cost. This practice is standard in modern swine nutrition. ### Fiber Sources and Specialty Ingredients Soybean hulls, wheat middlings, and rice bran are moderate-fiber byproducts that can replace a portion of grain in gestation diets. They provide bulk and help sows feel full without adding excess energy. Wheat middlings have about 15 to 17 percent crude protein and are a common ingredient in gestation rations. Milling byproducts like rice bran and wheat bran are high in phosphorus but much of it is bound as phytate. Add phytase enzyme to improve phosphorus availability. Rice bran is high in fat and can become rancid quickly, so use stabilized rice bran and store it in cool conditions. Culled vegetables, fruits, and root crops can be fed to swine in small amounts. Pumpkins, squash, culled potatoes, and surplus apples provide energy and moisture but are low in protein and most minerals. Treat them as a supplement, not a primary feed, and introduce them gradually to avoid digestive upset. Never feed rotten or moldy produce, and wash soil from root crops to reduce the risk of clostridial diseases. ## Step-by-Step Guide to Substituting Feed Ingredients ### Step 1: Define Your Goal and Constraints Write down why you are making a substitution. Are you trying to cut cost per ton, reduce reliance on a scarce ingredient, or use a locally available byproduct? Your goal determines how aggressive you can be with inclusion rates. Also list your constraints: available ingredients, storage capacity, mixing equipment, and the stage of production you are feeding. ### Step 2: Gather Nutrient Data Collect nutrient analyses for your current ration ingredients and for every candidate substitute. Use the same basis for all values, either as-fed or dry matter. If you are using a feed formulation software, enter the values directly. If you are calculating by hand, convert everything to the same moisture level first. ### Step 3: Set Maximum Inclusion Rates Decide how much of the substitute you are willing to use based on published recommendations and your own experience. Start conservative. For a new ingredient, begin at 5 percent of the diet. For well-characterized ingredients like DDGS or wheat, you can start at 10 to 15 percent. Never jump to a high inclusion rate without a trial. ### Step 4: Rebalance the Ration The most common mistake in swine feed substitution is replacing one ingredient with an equal weight of another. This fails because nutrient densities differ. Instead, use a spreadsheet or formulation software to solve for the new ingredient amounts that meet the target nutrient levels. For a simple two-ingredient substitution, calculate the nutrient contribution of the ingredient you are removing and then determine how much of the replacement you need to match that contribution. For example, if you remove 100 pounds of corn and replace it with wheat, you need less wheat by weight because wheat has higher protein and similar energy. But you also need to account for the extra protein and adjust soybean meal downward. For complete rations, use a least-cost formulation program. These programs solve for the combination of ingredients that meets all nutrient requirements at the lowest cost. Most feed mills have access to such software, and several affordable options exist for independent producers. ### Step 5: Add Missing Nutrients After rebalancing the major ingredients, check the amino acid profile. If your alternative protein source is lower in lysine than soybean meal, add synthetic L-lysine. If you are using high-fiber ingredients, consider adding a commercial enzyme product containing xylanase and beta-glucanase to improve nutrient digestibility. Calcium and phosphorus will almost certainly need adjustment when you change protein sources. Soybean meal has moderate calcium and low phosphorus. Canola meal has higher calcium. DDGS has high phosphorus. Recalculate the calcium and available phosphorus in the new ration and adjust limestone and dicalcium phosphate or monocalcium phosphate accordingly. ### Step 6: Test the New Ration on a Small Group Before you switch the entire herd, run a 7 to 10 day trial on a small group of pigs that represents your typical population. Monitor feed intake, water consumption, stool consistency, and behavior. Weigh the test group at the start and end of the trial if possible. If intake drops more than 10 percent or if you see persistent loose stools, reduce the inclusion rate or reformulate. ### Step 7: Transition the Herd Gradually When you are ready to introduce the new ration to the full herd, do it over 3 to 5 days. Mix increasing proportions of the new feed with the old feed. A typical schedule is 25 percent new on day one, 50 percent on day two, 75 percent on day three, and 100 percent on day four. This gradual transition reduces feed refusal and minimizes digestive upset. ### Step 8: Monitor Performance and Adjust Track average daily gain, feed conversion, and mortality for at least two weeks after the full transition. Compare these numbers to your historical averages for the same stage of production. If feed conversion worsens by more than 5 percent, the substitution may not be cost-effective even if the feed is cheaper per ton. Remember that the goal is lower cost per pound of gain, not lower cost per ton of feed. ## Common Mistakes in Swine Feed Substitution ### Substituting by Weight Instead of Nutrient Content This is the most common and most costly error. A ton of wheat is not the same as a ton of corn, and a ton of DDGS is not the same as a ton of soybean meal. Always formulate on a nutrient basis. ### Ignoring Particle Size Pigs digest grains better when they are ground to the correct particle size. Corn and sorghum should be ground to 650 to 750 microns for grower-finisher pigs. Wheat can be ground slightly coarser, around 700 to 800 microns. Barley should be ground to 600 to 700 microns because of its fibrous hull. If you switch grains without adjusting the grinder, you may see reduced digestibility and more feed wastage. ### Using Moldy or Spoiled Ingredients Alternative ingredients are often byproducts that were not intended for human consumption. They may have been stored improperly before you received them. Check every load for mold, off-odors, and signs of insect infestation. Test suspect loads for mycotoxins, particularly aflatoxin, vomitoxin (DON), and fumonisin. Feeding moldy grain to swine can cause reduced intake, immune suppression, and reproductive failure. ### Forgetting About Mycotoxin Synergy Even if each ingredient tests below the action threshold for a single mycotoxin, combining multiple contaminated ingredients can cause problems. For example, corn with low-level vomitoxin combined with DDGS that also has low-level vomitoxin can produce a ration that exceeds safe levels. Test the final mixed ration, not just individual ingredients. ### Overlooking Water Intake Some alternative ingredients, especially those high in fiber or salt, increase water consumption. This can lead to wet floors, increased manure volume, and higher lagoon loading. Make sure water lines and drinkers can handle the increased demand, and monitor manure consistency closely. ### Making Changes During Critical Periods Do not introduce major feed substitutions during breeding, farrowing, or the first week after weaning. These are stress periods when pigs are more sensitive to diet changes. If you must switch feeds, do it during a stable phase of production. ### Assuming All Batches Are Identical Byproducts vary from load to load. Bakery meal from a different supplier, DDGS from a different ethanol plant, and canola meal from a different crush facility can have substantially different nutrient profiles. Test each new load and adjust your formulation accordingly. ## Decision Thresholds for Substitution Knowing when to substitute is as important as knowing how. Use these thresholds as general guidelines, not hard rules. ### Cost Thresholds Calculate the cost per unit of energy and the cost per unit of lysine for each ingredient. If an alternative energy source costs less per megacalorie of ME than your current grain, it is worth considering. Similarly, if an alternative protein source costs less per gram of digestible lysine than soybean meal, it is a candidate for substitution. A practical rule of thumb is that an ingredient must save at least 5 percent of the total ration cost to justify the risk and labor of switching. Smaller savings may be erased by reduced performance or increased feed wastage. ### Performance Thresholds If a substitution causes average daily gain to drop more than 5 percent or feed conversion to worsen by more than 5 percent, the economic benefit is questionable. Calculate the cost per pound of gain for the new ration. If it is higher than the old ration, switch back or reformulate. ### Health Thresholds Stop the substitution and call your veterinarian if you see any of these signs within a few days of a diet change: - Feed intake drops by more than 20 percent for more than 48 hours - More than 5 percent of pigs have diarrhea or loose stools lasting more than 3 days - Pigs show signs of lethargy, incoordination, or neurological symptoms - Sows refuse feed for more than 24 hours - Any pig dies unexpectedly after a ration change ## Monitoring and Recordkeeping for Substituted Rations ### Daily Monitoring During the first two weeks after a diet change, check pens at least twice daily. Look at [feed bunk management](/knowledge/animal-farming/beef-cattle/feedlot-feed-bunk-management-reading-adjusting-intake), water consumption, manure consistency, and pig behavior. Healthy pigs on a well-balanced ration are active, curious, and eager to eat. Lethargy, rough hair coats, and tucked-up abdomens are warning signs. ### Weekly Monitoring Weigh a sample of pigs weekly to track average daily gain. If you do not have a scale, monitor feed disappearance and compare it to expected intake for the stage of production. Keep a simple log of any health treatments, because an increase in scour treatments or respiratory treatments can indicate a nutrition-related immune suppression. ### Performance Records For each group of pigs, record the ration formula, ingredient costs, dates of diet changes, starting and ending weights, total feed consumed, and days on feed. Calculate feed conversion for each group. Over time, these records will tell you which substitutions work on your farm and which ones cost you money. ### Feed Ingredient Log Keep a log of every load of feed ingredient you receive. Record the supplier, delivery date, moisture content, nutrient analysis, and any test results. This log is essential for tracing problems back to a specific load and for verifying that your feed mill is providing what you paid for. ### [Body Condition Scoring](/knowledge/animal-farming/farm-management/body-condition-scoring-a-tool-for-feed-management) for Sows If you are substituting ingredients in gestation diets, body condition scoring is your best monitoring tool. Score sows on a 1 to 5 scale every two weeks. A score of 3 is ideal. If sows are losing condition, the ration energy is too low. If they are gaining excess condition, reduce energy. Adjust feeding levels or reformulate before the sows reach farrowing. ## When to Call a Veterinarian or Extension Agent ### Call Your Veterinarian When - Pigs refuse feed for more than 48 hours after a diet change - Diarrhea is severe, bloody, or persists beyond 3 days - You see neurological signs such as circling, head pressing, or tremors - Multiple pigs die suddenly after a ration change - Sows abort or fail to farrow normally after a feed switch - You suspect mycotoxin contamination and need guidance on testing and treatment ### Call Your Extension Agent or Nutritionist When - You are considering a new ingredient and need current nutrient values or inclusion recommendations - You want help interpreting a feed analysis report - You need assistance with ration formulation software - You are planning a major diet change and want a second opinion - You want to compare the economics of different feeding programs for your region ### Testing Resources Your state veterinary diagnostic laboratory can test feed for mycotoxins, heavy metals, and nutrient content. The USDA APHIS Swine Health website provides information on reportable swine diseases and biosecurity practices. The National Pork Board offers producer education materials on nutrition and feed management. The FAO Pig Production and Animal Production and Health websites provide international reference information on feed ingredients and swine nutrition. ## Frequently Asked Questions ### Can I feed whole corn instead of ground corn to save on processing costs? Whole corn passes through the digestive tract largely undigested. Pigs cannot break the hard seed coat, so much of the starch and protein is lost in the manure. Grinding corn to 650 to 750 microns improves digestibility by 10 to 15 percent. The cost of grinding is almost always recovered through better feed conversion. If you do not have a grinder, consider buying ground grain from a local mill instead of feeding whole corn. ### How much DDGS can I feed to finishing pigs without affecting carcass quality? Most nutritionists recommend keeping DDGS at 20 percent or less of the finishing diet. At higher levels, the unsaturated fat in DDGS can make carcass fat soft and oily, which reduces carcass value and can cause problems at the packing plant. If you are feeding DDGS at 15 to 20 percent, consider reducing added fat in the diet and monitor carcass fat quality at marketing. ### What is the best way to introduce a new feed ingredient to a sow herd? Introduce new ingredients during mid-gestation when sows are not under the stress of breeding or farrowing. Start with a 25 percent inclusion of the new ration mixed with 75 percent of the old ration for 3 days, then 50-50 for 3 days, then 75-25 for 3 days, and finally 100 percent new. Monitor feed intake closely. Gestating sows are often fed restricted amounts, so any reduction in intake can cause sows to lose condition rapidly. ### Can I feed bakery waste to pigs without processing it? Bakery waste should be processed before feeding. Whole bread, cookies, and crackers contain packaging materials that pigs cannot digest and that can cause intestinal blockages. Most producers use a hammer mill to grind bakery waste into a uniform meal. Remove all packaging and metal before grinding. Bakery meal must be stored in a dry, cool place and used within a few weeks because it goes rancid quickly. ### Are there any alternative feeds I should never give to pigs? Never feed pigs uncooked meat or meat byproducts, which can transmit diseases including [African swine fever](/knowledge/bioinformatics/african-swine-fever-computational-models-for-early-detection-and-spread-prediction-in-wild-boar-populations) and foot-and-mouth disease. Do not feed raw potatoes, which contain solanine, a toxic compound. Avoid feeding avocado, which contains persin and can be fatal to pigs. Citrus peels contain essential oils that can reduce feed intake at high levels. Never feed moldy feed or feed that has been contaminated with chemicals, pesticides, or petroleum products. ### How do I know if my alternative ration is actually saving me money? Calculate the cost per pound of gain for the alternative ration and compare it to your previous ration. Divide the total feed cost for a group of pigs by the total weight gained. If the cost per pound of gain is lower with the alternative ration, the substitution is working. If it is higher, the cheaper feed is not actually cheaper after accounting for performance. ### Do I need to add synthetic amino acids when I use alternative protein sources? Often yes. Soybean meal has a very good amino acid profile. Most alternative protein sources are lower in lysine or have less digestible lysine. Adding L-lysine is usually cost-effective. Threonine and methionine may also need supplementation, especially in diets with high inclusion of DDGS or canola meal. Work with a nutritionist to determine the most cost-effective amino acid additions for your specific ration. ### Can I use the same alternative ration for all stages of production? No. Nutrient requirements differ dramatically between nursery pigs, grower-finisher pigs, gestating sows, and lactating sows. A ration that works well for gestating sows, such as one high in fiber and moderate in energy, will not support lactation. A high-fiber ration that is acceptable for finisher pigs will reduce growth rates in nursery pigs. Always formulate separately for each stage of production. ## Related Farming Guides This section will be populated with links to related farming guides on swine nutrition, feed management, herd health, and production economics. Check back for updated resources on ration formulation, feed storage, and alternative ingredient sourcing. ## 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.