Naturally occurring toxins in feedstuffs: Center for Veterinary Medicine Perspective

The objectives of this review are to provide 1) information on the FDA Feed Contaminants Program, 2) the legal history of aflatoxins and their current action levels, 3) a report on the levels of aflatoxins, fumonisins, vomitoxin, ochratoxin A, and zearalenone in domestic and import surveillance samples of feed during fiscal years 1989 through 1992, and 4) information on naturally occurring toxins encountered recently by the Center for Veterinary Medicine. Ten of 644 (1.6%) domestic corn samples and 7 of 106 (6.6%) domestic cottonseed samples contained aflatoxins at levels > 300 ppb. The mean fumonisin level in the 1990 survey of 85 corn screening samples was 12.1 ppm, and the values ranged from 2.6 to 32 ppm. The mean vomitoxin levels in the 1991 survey of 207 winter wheat samples and 206 spring wheat samples was 2.4 and .9 ppm, respectively. Ochratoxin A was not detected in 168 samples. Zearalenone was detected at levels > .15 ppm in only 1 of 161 samples. Cottonseed containing 13,000 ppm gossypol was recently implicated in the deaths of dairy cows. Crambe meal and canola meal are sanctioned for use in feed with certain restrictions, including the levels of glucosinolates. The FDA is continuing its surveillance and will strive to provide guidance on the increasing number of naturally occurring toxins.