The Differential Leucocyte Blood Count: Its Precision and Individuality in the Chicken

THE ability to evaluate an animal with respect to its physiological status is of great value to the environmental physiologist. When environmental alterations exceed the ability of an animal to change homeostatically (accommodate) it becomes physiologically “stressed.” This stressed condition results in, or is induced by an elevated corticosteroid blood level which is manifest in an altered leucocytic hematology. The lymphocytic and heterophilic response in the chicken to injections of ACTH and/or cortisone have been amply demonstrated previously (Huble, 1955; Newcomer, 1957; Wolford and Ringer, 1962; and Shapiro and Schechtman, 1949), as well as in our laboratory. Newcomer (1957) states, “The magnitude and constancy of the acidophilia obtained following ACTH injection suggests its possible use as a qualitative criterion of ACTH and/or acute stress in the bird.” The lymphocytic and heterophilic responses in the chicken to various stressors such as anoxia, restraint, environmental temperatures, starvation, handling, and centrifugation have also . . .