Effect of Thyroprotein-Feeding on the Gland and Organ Weights of Two-Year-Old White Leghorn Hens

DURING the past five years a group of White Leghorn hens have been fed a ration containing sufficient thyroprotein to induce a mild degree of hyperthyroidism (10 gm. per 100 lbs. of feed). Until the present year (6th laying year) the control group and those fed thyroprotein have laid about equal numbers of eggs during the fall and winter each year. However, during the spring and summer, the thyroprotein-fed group maintained egg production at a higher level. With advancing age, the yearly egg production of the thyroprotein-fed group has declined far less than the control group. (Turner and Kempster, 1947). The question has been raised as to the effect of continuous thyroprotein-feeding upon the body composition and gland and organ weight. Data was presented on the gland and organ weights of a limited number of Rhode Island Red hens fed thyroprotein for two consecutive years in comparison with normal hens . . .