Insecticides currently in use for pest control on dairy cattle offer little hazard of toxicity to the cow, dairyman, consumer, or the environment. Pesticides that cause significant residues in milk cannot be used on dairy cattle or in dairy barns. Since the cow rapidly excretes pesticides from her circulating blood into milk, it is evident that only pesticides that are metabolized rapidly, and are safe to mammals, may be used. This consideration rules out use of the persistent pesticides that are hazardous by magnification in the food chain. The insecticides we rely on, mainly rapidly degraded organophosphorus compounds, are discussed according to: method of use; toxicity to cattle, laboratory rats, birds, fish, wildlife; degradation time; tolerance in milk; and hazard to the consumer of dairy products. Only a small amount of these insecticides enters soil and water following proper use on dairy farms. Their persistence is short. Degradation products are explored, noting their very low hazard for toxic environmental contamination.
1Presented at the 60th Annual Meeting of the International Association of Milk, Food, and Environmental Sanitarians, Rochester, New York, August 13–16, 1973.