Heptachlor residue accumulation and depletion in broiler chickens

Broiler chickens were fed heptachlor in concentrations of 0, 0.01, 0.03, 0.1, and 0.3 mg/kg of the ration for the first 8 weeks of life. There were no adverse effects on health or performance. Residue concentrations in adipose tissue increased rapidly for 1 to 2 weeks and then tended to plateau at concentrations about five times greater than those in the rations. Birds exposed only during the 7th week of life stored 25% as much residue as did the chickens exposed in the 1st week, but the former also ate only 63% as much feed. Fat extracted from liver and muscle contained more residue than did fat extracted from adipose tissue. The ratio of the concentration of heptachlor to its epoxide metabolite was higher in muscle fat than in heptic or abdominal fat. Residue concentrations depleted by about half in the first 4 weeks after cessation of exposure.