The aim of this study was to determine the contamination of finishing pigs with polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs) after feeding either uncontaminated feed or feed contaminated with 0,75, 2 or 4 ng/kg toxic equivalents (TEQ; calculated by multiplying individual congener concentrations by congener-specific toxicity equivalency factors).
The feed was mixed with special amounts of pure substances of PCDD/Fs to get the estimated contamination of 0,75, 2 and 4 ng TEQ/kg feed. One group was fed with contaminated feed only for the weaning period (6 weeks), and one for the first 8 weeks of the finishing period, the others for the whole finishing period. After slaughtering the edible parts of the belly, loin and fore end were collected. The samples of group 2 an 4a were investigated raw as well as roasted.
Fattening yield and feed conversion of animals of all groups (kg feed/kg weight gain) were in the normal range.
The PCDD/Fs content of 1 kg fat of the belly, loin and fore end in relation to the intake was between 0,016 and 1,39 %. There was a decrease in dioxin residue after a 12 weeks period but not after a 4 weeks period of feeding an uncontaminated feed. A threshold value of 0,75 ng TEQ/kg feed, when fed at least 12 weeks can cause PCDD/F-intake of humans higher than German TDI (tolerable daily intake)-values if more than 400 g roasted belly per day is eaten. The residue levels of PCDD/F of loin and fore end have shown, that more than 1 kg consumed would be necessary to meet the TDI-value.