In this study, we investigated how the suppressive effect of dioxins [polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs)] transfer from the feed to the eggs of laying hens by using activated carbon as a feed additive. Four groups of six hens were housed as two control groups and two exposure groups for a period of 20 weeks. Two control groups were fed with either the basal feed (Control) or the basal feed with activated carbon added (Control + C). Another two exposure groups were fed with feed contaminated by standard solutions of dioxins alone (Exposure) and contaminated feed with activated carbon added (Exposure + C). For each group, there was no significant effect on the growth rate, the levels of biochemical blood components, histopathological condition of organs or the egg laying performance; these were around the standard levels for poultry in general. Moreover, the results in this study showed the efficacy of activated carbon as a feed additive as it reduces the risk of food pollution by dioxins. The dioxin concentration in the eggs of the Exposure group gradually increased following the start of egg laying but reached a steady state after about a month. In contrast, the dioxin concentration for the Exposure + C group was stationary and below the maximum EU level. This reduction due to activated carbon was also observed in the muscle and abdominal fat. Fat-soluble vitamin concentrations in the eggs of the Exposure + C group were lower than that in the eggs of the Exposure group. However, the addition of activated carbon to animal feed could obviate the remote potential for accidents causing unintentional food pollution with dioxins.
(Bacterial and Parasitic Disease Research Division)
References:
Fujita H. et al. (2012) Chemosphere 88:820-827
