“…The thyroid hormones, although not essential for initiation or maintenance of lactation, may be important in regulating the level of milk secretion. This conclusion is based primarily on studies showing that thyroidectomy reduces, but does not abolish, milk secretion while under suitable conditions the administration of thyroxine generally induces an increase in milk secretion (Reineke, 1946;Benson and Cowie, 1957;Blaxter, 1952). Grosvenor (1961) has reported that thyroid secretion rate obtained from primiparous lactating rats during the first 14 days of lactation was 1307o more than obtained from non-lactat¬ ing females of the same age.…”