Effects of mycotoxins on swine

Zearalenone

  • has estrogenic effect
  • levels of 1 ppm (ppm = mg/kg) and greater can cause the following:
    • gilts — enlargement of the uterus, vulva and mammary glands, prolonged heat and poor conception
    • boars (young) — reduced sperm production and libido
    • boars (mature) — no affect
    • sows and gilts — failure to show heat, abortion, stillborn, low fertility, rectal and vaginal prolapses may occur in extreme cases
  • can be transferred to piglets through sow's milk, causing enlarged vulvas in female piglets
  • does not affect feed intake or growth rate

Vomitoxin (Deoxynivalenol or DON)

  • is a tricothecene
  • affects the gastro-intestinal tract
  • levels of 1-2 ppm cause a reduction in feed intake and, as a result, rate of gain
  • between 0.5 and 3 ppm, it is wise to dilute with clean grain
  • as levels increase above 5 ppm, decrease in feed intake may become severe
  • levels of 10-20 ppm cause vomiting and complete feed refusal, resulting in reduced body weight gain or body weight loss
  • pigs will initially consume sufficient amounts of the ration to induce vomiting, but will voluntarily reduce intake to stop vomiting
  • sows are more tolerant than young pigs
  • low levels can suppress the immune system

T-2 Toxin

  • is a tricothecene
  • more potent but less common than vomitoxin
  • more likely to be produced during long periods of cool wet weather
  • 1 ppm or greater causes vomiting and decreased feed intake, growth rate
  • 16-20 ppm causes complete feed refusal

On-farm tests for mycotoxins

Pigs can be used to test the presence of mycotoxins on the farm.

Zearalenone

  • feed 4-6 week old gilts suspect feed for 7-10 days and compare the redness and size of their vulvas with same aged gilts fed clean feed
  • slight redness and swelling after 1 week indicates 1 ppm zearalenone
  • considerable swelling and redness after 3-4 days indicates 5 ppm or more

Vomitoxin

  • feed 4-6 week old piglets (for feeder operations use 35 kg pigs) suspect feed for 1 week
  • compare feed intake and growth rate with same aged pigs fed clean feed
  • levels of 1-2 ppm vomitoxin cause slight decrease in feed intake and growth rate which may be difficult to detect
  • at 3-5 ppm, reduced feed intake will be apparent
  • levels of 10 ppm cause dramatic decreases in feed intake, vomiting within 1 day of feeding and slow growth rate

T-2 toxin causes decreases in feed intake at 1 ppm

As pigs eating T-2 and vomitoxin respond the same way, you need a lab test to show if one or both are present in your grain or feed.