Effects of chronic ingestion of ochratoxin a on blood levels and excretion of the mycotoxin in sheep.
Ruminants are relatively resistant to the acutely toxic effects of ochratoxin A, due to extensive degradation of ochratoxin A to its less toxic metabolite ochratoxin alpha by rumen microorganisms. However, most estimates of the degradation capacity for ochratoxin A in ruminants are based on in vitro studies. In the current study, the metabolism of ochratoxin A was investigated over a period of 29 days, feeding various doses of the mycotoxin (0, 9.5, 19.0, and 28.5 mug ochratoxin A/kg body weight) to sheep. Animals were fed diets consisting of 70% concentrates and 30% grass silage. Significant concentrations of undegraded ochratoxin A were detected in serum of sheep at all levels of ochratoxin A tested. Serum concentrations of ochratoxin A slightly accumulated with time of exposure and were linearly dependent on the administered dose of ochratoxin A. Furthermore, a constant proportion (6-8%) of the dose was excreted in the urine. The results of this study indicate that even at moderate to low levels of ochratoxin A in the diet, considerable amounts of the mycotoxin are absorbed by ruminants and may accumulate in tissues. Therefore, feeding of ochratoxin A-contaminated feedstuffs to ruminants does not seem to be a reliable means for using these feedstuffs.
Institute of Animal Nutrition, Physiology, and Metabolism, Christian-Albrechts-University, 24098 Kiel, Germany. blank@aninut.uni-kiel.de
Ralf
R
Blank
Jan-Peter
JP
Rolfs
Karl-Heinz
KH
Südekum
Andrew A
AA
Frohlich
Ronald R
RR
Marquardt
Siegfried
S
Wolffram
D000818:Animals; D004032:Diet; D005243:Feces / Q000737:chemistry; D005506:Food Contamination; D009793:Ochratoxins / Q000008:administration & dosage* / Q000097:blood* / Q000493:pharmacokinetics; D006109:Poaceae; D012417:Rumen / Q000737:chemistry; D012756:Sheep / Q000097:blood*; D012820:Silage
D009793:Ochratoxins; C025589:ochratoxin A