A Thiouracil-Thyroprotein Treatment for Fattening Poultry , ,

DURING the past few years several reports have appeared on the use of chemical compounds to influence thyroidal activity. One of these, thiouracil, has been shown to produce a hypothyroid condition as measured by decreased metabolism (Reineke, Mixner, and Turner, 1945; Mixner, Tower, and Upp, 1946; and Shaffner and Andrews, 1948). The use of this drug is of interest because the induced hypothryoidism results in an increased deposition of fat and improved market grade in growing chickens (Andrews and Schnetzler, 1946; Andrews and Bohren, 1947). However, Kempster and Turner (1945) and Glazener and Jull (1946) have also shown that thiouracil depresses rate of growth when fed over extended periods (4–5 weeks). Since thiouracil, at the levels fed, was presumably effective in shutting off the elaboration of endogenous thyroxine, it seemed possible that a milder degree of hypothyroidism might induce fattening while permitting normal growth. Thyroprotein (iodinated casein) has been . . .