Dieldrin poisoning of chickens during severe dietary restriction.

Two experiments were conducted to establish the effect of dieldrin on survival of chickens during severe dietary restriction. White Leghorn hens were fed rations containing 0, 1, 5, 10, and 20 ppm of dieldrin for 12 weeks. At this time, dieldrin had accumulated in the body fat in direct proportion to the amount fed. During subsequent feed restriction, survival of hens fed 10 or 20 ppm dieldrin was significantly shorter than that of hens fed 0, 1, or 5 ppm dieldrin. Dieldrin concentration in blood declined during the first and second weeks following feed removal, then it increased. Blood sampling was terminated at the end of 4 weeks because nearly all hens had died, but dieldrin concentration in the blood had not increased appreciably over the concentration observed in blood at the time that feed was removed.