The Effect of Progesterone on Egg Formation in Sixteen-Week Old Pullets

Abstract

ABSTRACT PROGESTERONE, a steroid hormone found in the blood of hens and roosters but not in capons (Fraps et al., 1949), has been shown to affect the ovary differently, depending on dosage, interval of treatment and method of administration. Shaffner (1955) reported that hens injected with progesterone ceased egg production immediately after treatment and showed signs of heavy molt from ten to fourteen days later. He indicated that most of the birds had resumed egg production eight weeks following the treatment. Egg weight and body weight were not influenced by the treatments. Different methods of administering progesterone to yearling hens were compared by Adams (1955) who found that whether fed, implanted, or injected, progesterone caused a decrease in egg production and an increase in the rate of primary wing feather molt. Estrogen primed rabbits need 200 mg. of progesterone orally to equal uterine proliferation of rabbits injected subcutaneously with 0.25 to . . .