MOLDY GRAINS, MYCOTOXINS AND FEEDING PROBLEMS

Introduction

Aflatoxins

Zearalenone

Trichothecenes (DON, T-2)

Fumonisins

Ochratoxin

Preventative Practices

Detrimental Feed Concentrations

What is ppm & ppb?

Plant Disease Associations

Links

 

Fumonisins  

Toxin Characteristics

Fumonisins are  toxins produced by Fusarium species that grow on several agricultural commodities, mainly corn, in the field or during storage. The disease, Fusarium kernel rot of corn, is caused by Fusarium verticillioides and F. proliferatum,  common producers  of fumonisin.

More than ten chemical forms of fumonisins have been isolated, of which FB1 is the most prevalent in contaminated corn and is believed to be the most toxic.

 

Crops and Weather Conditions

Levels of fumonisins in corn are influenced by environmental factors such as temperature, humidity and rainfall during pre-harvest and harvest periods. 

  • High levels of fumonisins are associated with hot and dry weather, followed by periods of high humidity.

  • High levels of fumonisins may also occur in corn that has been damaged by insects and birds. 

  • Hybrids genetically engineered to resist insects may have lower levels of fumonisins.

  • Improper storage conditions, such as moisture above 18%,  will lead to increase fumonisin levels.

Impact on Animal Health

Fumonisins are associated with a variety of adverse health effects in livestock. 

  • Fumonisins are known to cause a fatal disease in horses, leucoencephalomalica. 

  • Swine can develop fluid in the lungs (pulmonary edema) and/or liver damage which causes reduced weight gain. 

  • Cattle and sheep are comparatively resistant to fumonisins with mild liver damage and moderate feed refusal.

  • Poultry are more resistant to fumonisins than other common livestock.

Guidelines for Grain Use

 

FumonisinS FDA Advisory Level Concentration at which regulatory agency urges caution
Humans - Dry milled corn products ( i.e. corn meal, corn grits, etc) with fat content of <2.25% dry weight basis

2 ppm

 
Humans - Dry milled corn products ( i.e. corn meal, corn grits, etc) with fat content of >2.25% dry weight basis 4 ppm

Humans - Popcorn

3 ppm

Horses

5 ppm, not to exceed 20% of diet

Swine

20 ppm, not to exceed 50% of diet      

Breeding ruminants, breeding poultry

30 ppm, not to exceed 50% of diet      

Ruminants > 3 months old being raised for slaughter

60 ppm, not to exceed 50% of diet      

Poultry being raised for slaughter

100 ppm, not to exceed 50% of diet

All other species or classes of livestock  

10 ppm, not to exceed      50% of diet