Withdrawal time required for clearance of aflatoxins from pig tissues

Abstract

The time necessary to obtain clearance of aflatoxins from the tissues of the pig after removal from a contaminated diet was determined in two trials involving 20 pigs in each. There was a significant reduction in aflatoxin levels in all organs and tissues 1 day after placing the pigs on an aflatoxin-free ration. After 2 days, only one pig contained trace amounts (<0.50 pg/kg) of aflatoxins in the tissues. Four days after removal from the contaminated diet, there were no detectable levels of aflatoxins in any of the tissues.It was also found that a naturally contaminated diet containing only 20 and 31 pg/kg aflatoxins B1 and B2, respectively, resulted in traces of aflatoxins B,, Bz, M,, and Mz in the livers and kidneys after 13-14 h withdrawal from the contaminated diet, although none were detected in any other tissues.Transmission of aflatoxins through animal products (meat, milk, and eggs) to man may result in exposure to these potent carcinogenic compounds (Armbrecht, 1971; Rodricks and Stoloff, 1977). Several research groups (Krogh et al., 1973;Murthy et al., 1975; Hayes et al., 1978; Furtado et al., 1979) have shown that aflatoxins can be deposited in the tissues of the pig, which is confirmed in a review by Stoloff (1979). Thus, meat can provide a dietary source of exposure for humans. Little is known about the length of time required for the pig to metabolize aflatoxins and, thus, clear their tissues of these contaminants.The present study was designed to determine the length of time necessary to achieve tissue clearance of aflatoxins from pigs fed a contaminated diet. This was accomplished by feeding pigs on an aflatoxin-spiked diet for 42 days and measuring the amount of these toxins and their metabolites in the tissues immediately after removal and comparing them to a similar group of animals fed an unspiked basal diet. The remaining pigs were fed a control diet and pigs from all groups were slaughtered at 1,2,4, and 8 days after being placed on this diet to ascertain the length of time necessary to obtain tissue clearance. MATERIALS AND METHODSFeeding Trials. Two feeding trials with 20 weanling crossbred pigs in each were carried out by using the same basal ration described earlier by Furtado et al. (1979). Feed and water were allowed ad libitum. The pigs were weighed weekly and feed consumption records were kept. Allotment into groups was based on sex, litter, and weight. In each trial 4 pigs were fed the control (unspiked) diet, and 16 were used to determine the time necessary for tissue clearance. In both trials, the spiked diets contained 551 and 355 pg of aflatoxins B1 and B2 per kg of feed, respectively, and the spiked and control (unspiked) rations were fed for 42 days. Then the four control pigs and four of the pigs on the experimental diet were slaughtered within 13-14 h after being taken off feed. The remaining pigs in each trial were placed on an uncontaminated control ration and fed until removed for slaughter at the selected time intervals.In trial 1, after the initial feeding period of ...

The role of mycotoxins in pig reproduction: a review

“…In case of feed concentrations between 355 and 551 µg/kg, the average half-life time is 24 hours. After 48 hours, only minute quantities of residues were found (< 0.5 µg/kg) and after four days there were no residues left (Furtado et al, 1982) (Table 5). …”