Observations on Radiothyroidectomized Chickens

EFFECTS of partial and complete thyroidectomy on growth, plumage, and reproduction in the fowl have been reviewed by Sturkie (1954, Ch. 19), who points out that the operation is difficult and not always successful. A much easier procedure is to destroy the thyroid tissue by injecting large doses of radioactive iodide, I131, which rapidly accumulates in the thyroids and “bombards” the thyroid cells with electrons. This technique was termed “radio-thyroid-ecrexis” by Winchester et al. (1949), who were the first to use it with chickens, but is more popularly known as “radiothyroidectomy.” The purpose of this paper is to present some observations made and experimental data obtained in three experiments with radiothyroidectomized (RTx) chickens. Some of these observations and data have been briefly presented in a preliminary report (Mellen and Wentworth, 1959). MATERIALS AND METHODS In each experiment, 10 randomly-chosen crossbred chicks were radiothyroidectomized and approximately the same number of hatch-mates …