The effects of dietary dieldrin on residues in eggs and tissues of laying hens and the effects of phenobarbital and charcoal on these residues

Summary Laying hens were fed a total of 18 mg of dieldrin over an 11-day period. Some of these were fed charcoal and others received phenobarbital during the 11-day period. Neither treatment affected the amount of dieldrin residue in the eggs. The maximum dieldrin residue in the eggs was about 4 ppm and occurred about 20 days after the initial dosage or about 9 days after cessation of dosage. The dieldrin residue levels in the livers ranged from 0 to 228 ppb and the brains contained no dieldrin residue. No change in shell thickness of the eggs or weights of the chickens was noted.