Mycotoxicosis in pigs: Causes and treatment.Dr.Kedar Karki

Mycotoxicosis is a term that refers to the toxicity that occurs when hogs eat grain that has a growth of molds. These molds grow in feed or in the grains used to make feed if the grain is damp, improperly stored, or if equipment is not cleaned of damp grain in between processing. Feeders that are not water-tight can cause an overgrowth in warm, damp conditions as well.

This is why feeders must be inspected regularly and any damp feed removed from either the storage bin or from the feeding trays.

Aspergillus and Fusariam are two specific kinds of mold that cause problems if the amounts are too high in the feed source. There may be small amounts naturally occurring but in toxic amounts it can cause health problems in the herd. Mycotoxin is the broad term used to describe the toxic effect of any of these molds. They can cause severe problems in other species, including humans but this discussion is restricted to the effects on swine.

If these myotoxins are present in the feed from any source, the symptoms and signs can be mild until damage is done. In growing pigs, often the only sign is poor growth. The actual damage can be to the liver and kidneys, and these are not always apparent in examination of the live pigs. Many times poorly growing pigs appear sick, but not until autopsy is the diagnosis made. Jaundice sometimes is a sign but by the time it reaches this level it is too late to help the pig.

Another sign in growing pigs of mycotoxicosis is rectal or vaginal prolapse of pigs. The reddening of the vulva of young gilts is a sign, and it is one of the few telltale signs of mycotoxicosis. Feed sources should be changed immediately if this symptom is noticed. A careful evaluation of the feed source and the feed delivery system should reveal the source. If no source is readily found, change the source of the feed that is purchased. Be especially aware of moldy feeds and NEVER purchase old or moldy feed. Some mold growths are harmless but you do not know without testing if this is so.

In the breeding herd, the signs are aborted pigs or failure to breed. Any feed that is not top quality should not be fed to pregnant sows and gilts due to the risk of mycotoxicosis. If feed is only mildly wet, the only animals it should be fed to are older sows or boars. Feed can tolerate wetness for a short period of time, but after 72 hours, it should be assumed to be toxic to avoid problems. The toxic nature of the

mycotoxins make the damage permanent if the damage is to the liver or kidneys.

The only cure is to remove the source of contamination. Avoid all wet or moldy feed and always purchase your feed from reputable dealers. If you mix your own feed, avoid any grain that is not stored properly and has any appearance of mold. Unfortunately, the molds that are toxic are not always visible to the naked eye, so know the source and the history of your feed. If you store your own grain, make sure it is properly dried and continue to keep the humidity down in the grain with grain dryers.