Arsenic residues in eggs from laying hens fed with a diet containing arsenic (III) oxide

Three groups of six hens each were fed for twelve days with diets containing 7.5, 15.0, and 30.0 mg arsenic per kg in the form of As2O3. A control group was included in the trial. The hens from each group were formed into three subgroups. The eggs of two hens, laid in three days, formed a composite sample. The As concentration in the egg whites and yolks was determined in duplicate by radiochemical neutron activation analysis. With increasing As concentration in the poultry feedstuff, its concentration in egg yolk and white also increased, but a plateau appears to be reached quite rapidly. The ratio between the As concentration in yolk and in white is nearly constant (1:3) for all three groups of hens, irrespective of the level of As in the feed. The concentration of arsenic in dry matter of whites was significantly higher than in the dry matter of yolks, while the concentrations of arsenic in fresh samples of yolks were higher in the comparison with fresh samples of whites, but the differences were not significant.