Studies of Feeding Aldrin to Dairy Cows

No Aldrin was detected in the milk of cows fed hay made from forage sprayed with 3.9 oz. of Aldrin per acre and harvested 7 days after spraying. No Aldrin was detected in the milk of cows fed less than 0.8 mg. of Aldrin per kilogram of body weight, or 28 p.p.m. of the diet. When 0.8, 1.0, 1.5, and 2.2 mg. of Aldrin per kilogram of body weight were fed, the average concentrations of Aldrin in the fat-corrected milk were 3.8, 4.3, 6.4, and 12.6 p.p.m., respectively. From 11 to 14% of the Aldrin administered was excreted in the milk. No Aldrin was detected in samples taken 18 days after cessation of Aldrin feeding. One animal that received 2.2 mg. of Aldrin per kilogram of body weight showed symptoms of toxicity on the 27th day of feeding and died after 29 days of feeding at this level of intake.