title: Suppressive effect of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and dioxin-like polychlorinated biphenyls transfer from feed to eggs of laying hens by activated carbon as feed additive.
abstract: In this study, we investigated the suppressive effect of 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 (White Leghorn egg-layers; age, 11weeks) were housed as two control groups and two exposure groups for a period of 20weeks. Two control groups were fed with either the basal feed "Control" or basal feed additing activated carbon "Control+C". Another two exposure groups were fed with feed contaminated (about 6ng TEQ kg(-1) feed) by standard solutions of PCDDs/PCDFs and DL-PCBs "Exposure" alone and contaminated feed adding activated carbon "Exposure+C". There was no significant effect on each groups for the growth rate, biochemical blood components, and egg production: these were around the standard levels for poultry in general. Moreover the results in this study showed the availability of activated carbon as a feed additive owing to the reduction in the risk of food pollution by PCDDs/PCDFs and DL-PCBs. The concentration in the eggs of the Exposure group gradually increased following the start of egg-laying but reached a steady state after about 1month. In contrast, the concentration for the Exposure+C group was stationary and below the maximum EU level (6pgTEQg(-1)fat). In comparison to the Exposure group, the Exposure+C group showed a significant decline in the percentage of bioaccumulation into the egg. This reduction due to activated carbon was also observed in the muscle and abdominal fat. The reductions were compound- and congener-dependent for DL-PCBs as follows: PCDDs/PCDFs, non-ortho-PCBs, and mono-ortho-PCBs were more than 90%, 80%, and 50%, respectively, irrespective of the type of tissues. Fat soluble vitamin concentrations in the eggs of the Exposure+C group showed lower trends than the Exposure group. The γ-tocopherol and α-tocopherol concentrations in eggs of Exposure+C group showed a significant reduction of about 40%. However, the addition of activated carbon into animal feed could obviate the remote potential for accidents causing unintentional food pollution with PCDDs/PCDFs and DL-PCBs.
authors.affiliation: Department of Environmental Science for Industry, Ehime University, 3-5-7 Tarumi Matsuyama, Ehime 790-8566, Japan. mrfujita@agr.ehime-u.ac.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Fujita
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Honda
authors.forename: Ryoji
authors.initials: R
authors.lastname: Iwakiri
authors.forename: Keerthi S
authors.initials: KS
authors.lastname: Guruge
authors.forename: Noriko
authors.initials: N
authors.lastname: Yamanaka
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Tanimura
mesh_terms: D000393:Air Pollutants / Q000032:analysis; D000821:Animal Feed; D000818:Animals; D001572:Benzofurans / Q000032:analysis / Q000494:pharmacology*; D004147:Dioxins / Q000032:analysis; D004531:Eggs; D004784:Environmental Monitoring; D011078:Polychlorinated Biphenyls / Q000032:analysis / Q000494:pharmacology*; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis / Q000494:pharmacology; D011108:Polymers / Q000032:analysis / Q000494:pharmacology*
chemical_list: D000393:Air Pollutants; D001572:Benzofurans; D004147:Dioxins; D000072317:Polychlorinated Dibenzodioxins; D011108:Polymers; C016068:polychlorodibenzofuran; D011078:Polychlorinated Biphenyls