?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=https%3A%2F%2Forgprints.org%2Fid%2Feprint%2F11254%2F&rft.title=Effect+of+Flock+Size+on+Dioxin+Levels+in+Eggs+from+Chickens+Kept+Outside&rft.creator=Kijlstra%2C+A.&rft.creator=Traag%2C+W.+A.&rft.creator=Hoogenboom%2C+L.+A.+P.&rft.subject=+Poultry&rft.description=To+decrease+dioxin+uptake+by+the+general+population+the+European+Union+(EU)+has+set+limits+to+the+dioxin+content+of+many+foodstuffs+including+eggs.+Eggs+from+free+foraging+chickens+are+known+to+have+a+higher+dioxin+content+as+compared+to+confined+laying+hens+and+it+is+the+question+whether+these+eggs+can+adhere+to+current+EU+regulations.+The+aim+of+the+study+was+to+investigate+parameters+that+are+involved+in+the+contamination+of+eggs+from+chickens+raised+under+%E2%80%9Corganic%E2%80%9D+conditions.++Samples+from+34+organic+farms+including+soil+and+earth+worm+samples+were+collected+between+September+and+December+of+the+year+2003.++Dioxin+levels+were+assayed+by+GC%2FMS.+Various+parameters+were+collected+by+on+farm+interviews.+Egg+dioxin+content+varied+between+0.4+and+8.1+pg+Toxic+Equivalents+(TEQ)%2Fg+egg+fat+with+a+mean+of+2.2+pg+TEQ%2Fg+egg+fat.+Nine+out+of+34+farms+exceeded+the+EU+limit+of+3+pg+TEQ%2Fg+egg+fat.+In+addition+dioxin-like+(dl)+PCBs+were+measured+and+8+samples+exceeded+the+limit+for+the+sum+of+dioxins+and+dl-PCBs.+Overall%2C+egg+samples+from+10+farms+were+non-compliant+with+either+the+dioxin+or+total+TEQ+limits.%0D%0ANo+statistically+significant+relation+could+be+observed+between+egg+dioxin+levels+and+the+concentration+observed+in+soil+or+earth+worms.+A+statistically+significant+association+was+observed+between+flock+size+and+egg+dioxin+and+dl-PCB+content.+This+effect+is+most+likely+attributable+to+the+fact+that+flock+size+is+related+to+the+time+chickens+spend+outside.+Restricting+outdoor+run+use+on+one+of+the+farms+resulted+in+a+decrease+of+the+egg+dioxin+content+to+a+level+that+was+within+the+EU+limits.+This+demonstrates+that+the+most+likely+contamination+source+is+the+soil+or+soil+organisms+but+that+the+behaviour+of+the+hens+determines+the+extent+of+the+contamination.+Following+the+completion+of+this+study%2C+a+dioxin+monitoring+protocol+has+been+set+up+in+The+Netherlands+to+prevent+marketing+of+eggs+with+raised+dioxin+levels.%0D%0A%0D%0A%0D%0A&rft.date=2007-09&rft.type=Journal+paper&rft.type=NonPeerReviewed&rft.format=other&rft.language=en&rft.identifier=%2Fid%2Feprint%2F11254%2F1%2FAbstract.doc&rft.identifier=+++Kijlstra%2C+A.%3B+Traag%2C+W.+A.+and+Hoogenboom%2C+L.+A.+P.+++(2007)+Effect+of+Flock+Size+on+Dioxin+Levels+in+Eggs+from+Chickens+Kept+Outside.+++Poultry+Science%2C+86+(9)%2C+pp.+2042-2048.++++++++