EFFECTS OF PROLONGED ORAL ADMINISTRATION OF LARGE DOSES OF PITUITARY ANTERIOR LOBE TO LAYING HENS

¹ Institute of Animal Genetics, University of Edinburgh

1. The effects of pituitary anterior lobe hormones by oral administration to domestic fowls has been studied. The doses used in these experiments were large (·5 to ·8 grm.) and the time of administration was prolonged (one month).

2. The effects of oral administration were positive, as evidenced by (a) increase in egg-size, increase in egg-number, and increase in weight of birds; (b) an increase in the number of follicles in the ovary and also an increase in their size, indicating more rapid growth; a stimulation of albumen-secretion in the oviduct, recognised in the increased percentage of albumen in the egg; also probably an effect on the muscular wall of the uterus.

3. The results were most striking in the early part of the year (before spring).