Aflatoxins and their Metabolites in the Tissues, Faeces and Urine from Lambs Feeding on an Aflatoxin-Contaminated Diet

Abstract

Twenty-four lambs were intoxicated with 2·5 mg of aflatoxin (AF) kg-1 in their feed for 21 days. Twelve lambs were slaughtered at day 21 and the remaining animals had an 8 day clearance period. Aflatoxins and their metabolites were detected in liver, kidneys, faeces and urine using TLC and fluorescence densitometry. During the intoxication period, the samples gave a wide range of concentrations, the lower extreme being in the liver and the kidney (0·03 μg kg-1 of AFG1) and the higher extreme in faeces (61·82 μg kg-1 of AFM1) and urine (27·84 μg litre-1 of AFM1). The average value of AFB1 (1·94±0·9 μg kg-1) was higher than AFM1 (0·35±0·17 μg kg-1) in the liver. In the kidney AFM1 (5·45±4·01 μg kg-1) was higher than AFB1 (1·29±0·84 μg kg-1). There were higher concentrations of AFM1 (27·2±16·1 μg kg-1, 7·37±6·53 μg litre-1, respectively, of average level) in faeces and urine, than of AFB1 (17·25±8·1 and 1·78±1·57 μg litre-1, respectively). AFB2a appeared in the kidney (0·05±0·03 μg kg-1) and urine (0·35±0·25 μg litre-1). The clearance time of AFB1 from the faeces was less than or equal to 8 days and in all samples aflatoxin residues were still detected on the 8th day of the clearance period although in low quantities. These results suggest that aflatoxin transfer to and elimination by the liver and the renal tissue is small and that the danger to humans consuming lamb meat is also small. The examination of the faeces and urine could be useful as markers to detect lambs consuming a contaminated diet. © 1997 SCI.