The selenium requirements of the hen and effects of a deficiency.

Hens were fed a diet low in selenium made up mostly of corn and torula yeast. Egg production and hatchability increased significantly when selenium was supplemented, while the percentage of infertile eggs and early dead embryos decreased. Anemia also resulted from the deficiency. A total of .05 mg. selenium per kg. (.04 from the basal diet plus .01 supplemental) was adequate to prevent signs of deficiency in a diet which contained no supplemental vitamin E or antioxidant. In a second experiment the anemia was classified as macrocytic.