Mycotoxins are a long-standing hidden risk on pig farms. Many farmers have a misconception: feed is considered moldy only when mold is visible to the naked eye or when it has clumped. In reality, most of the harm to pig farms comes from hidden mycotoxins. The feed looks normal, but toxin levels have already exceeded limits, continuously damaging the herd and causing a series of difficult problems that are hard to eliminate all at once.
Raw materials such as corn, soybean meal, wheat bran, and distillers' grains can develop mold during harvesting, drying, warehousing, transportation, storage in feed bins, and while leftover feed remains in troughs. Hot and humid conditions provide an ideal environment for mold growth. The risk of toxin levels in raw materials exceeding limits rises sharply, especially during the rainy season and periods of high humidity. Common mycotoxins include aflatoxins, zearalenone, vomitoxin, and T-2 toxin. Different toxins affect different target organs and cause different clinical signs.
Aflatoxins mainly damage the liver. After pigs consume them, feed intake may decrease, jaundice may occur, the skin and coat may turn yellow, and the pigs may become lethargic. The liver may enlarge and bleed, while immune function continues to decline. After vaccination, antibody levels may fail to rise, making the herd prone to recurrent illness and reducing the effectiveness of antibiotics.
Zearalenone primarily affects the reproductive system. Sows are most typically affected: gilts may show false estrus and vulvar swelling and redness; multiparous sows may experience irregular estrus, repeated failure to conceive, miscarriage, stillbirths, and an increase in weak piglets. Gilts in the nursery and finishing stages may develop vulvar swelling and redness. Many pig farms mistake this for other diseases, and repeated attempts to manage the condition fail to improve it.
Deoxynivalenol primarily attacks the digestive tract. Pigs may eat less, refuse feed, vomit, suffer damage to the intestinal mucosa, and experience recurrent diarrhea; the feed-to-meat ratio increases, growth slows, and piglets are more likely to become runts. T-2 toxin can cause ulceration of the skin and oral mucosa and a sharp decline in immunity.
The greatest danger posed by mycotoxins is immunosuppression. As toxins continue to accumulate in the body, they damage immune organs and weaken pigs’ resistance, making problems such as PRRS, porcine circovirus, and mycoplasma more likely to break out and making disease prevention and control many times more difficult. Toxins also accumulate in livestock, affecting production performance over the long term and causing ongoing losses for pig farms.
Many pig farms rely on a single mycotoxin binder for prevention and control, which is also a common shortcoming. Mycotoxin binders are divided into adsorption-based and degradation-based types, and their adsorption capacity varies for different toxins. It is difficult for a single mycotoxin control product to cover all toxins. For systematic prevention and control, start at the source of the raw materials.
First, strictly control raw materials upon receipt. When purchasing raw materials such as corn and wheat bran, test moisture first. Keep corn moisture within a safe range, and reject materials that are clumped, warm, musty, or contain many broken kernels. Broken kernels and insect-damaged kernels are favorite places for mold to grow, so screen out impurities.
Second, manage storage properly. Keep raw-material warehouses dry and well ventilated, and raise materials off the floor to prevent dampness. Follow the first-in, first-out principle and avoid stockpiling materials for long periods. Clean feed towers, feed lines, and troughs regularly. Leftover feed trapped in corners for a long time can easily become moldy. Many pig farms overlook contamination in feed lines, leading to repeated poisoning.
Third, choose a mycotoxin control solution scientifically. Select products based on the season and raw material conditions. Adsorbents are suitable for aflatoxins, while biodegradation products work better against deoxynivalenol and zearalenone. Use them as needed rather than adding the same product year-round. Also provide regular liver and gallbladder support to help the pigs metabolize toxins already ingested.
Fourth, monitor the pigs and take timely action to limit losses. If the farm experiences sow reproductive disorders, poor immune responses in the herd, diarrhea of unknown cause, or an increase in stunted pigs, first investigate mycotoxins rather than relying solely on antibiotics. Isolate severely poisoned pigs promptly, adjust their feed, and use a liver-support and detoxification plan.
Final summary: Mycotoxin prevention and control starts upstream rather than with remediation. Mycotoxin binders are only a fallback measure; control of raw materials, storage, and feed line cleaning are the key. Stop the continuous intake of toxins and protect the liver and immune system to stabilize herd performance and reduce reproductive problems and recurring diseases.