Abstract
With the introduction of the insecticide DDT (2,2-Bis(p-chlorophenyl) 1,1,1-Tri-chloroethane) and its suz bsequent widespread application, there came a need for a complete understanding of its toxicity, and metabolic effects in animals other than insects. Studies on several species of mammals have resulted in a rather wide variety of findings regarding the action of this compound. In general, mammals are extremely sensitive to relatively small amounts of DDT. On the other hand, birds have been shown to possess a high degree of resistance to this substance(l). Since experiments dealing with the effects of DDT on birds are notably less numerous than similar studies on mammals, it appeared that additional information regarding this important compound might be obtained from a study designed to reveal the effects of longterm poisoning in chickens. In the course of this study on cockerels, some interesting effects were noted on the development of the testes and secondary sex characters.
Method. White Leghorn cockerel chicks were selected at random and divided into 2 groups, one to serve as controls and the other as experimental animals. They were placed 1 in a commercial brooder and allowed free access to food and water. Two series of ex-3 periments were carried out involving a total 3 of 30 controls and 40 treated birds. Starting 1 on the 8th day after hatching, the experimental chicks were given daily subcutaneous injections of purified DDT (M.P. 109°). To minimize the possibility of lesions, the site of injection was varied. The amount of the compound administered was gradually increased during the course of the experiment from an initial dose of 15 mg per kilo of body weight in the young birds to a maximum of 300 mg per kilo near the terminal stages of the study.
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