THE EFFECT OF THYROIDECTOMY ON GROWTH IN THE SHEEP AND GOAT AS INDICATED BY BODY-WEIGHT

¹ The Department of Physiology and Biochemistry, Medical College, Cornell University, Ithaca, N.Y., U.S.A.

In sixteen pairs of twin lambs. mainly of the same sex, the thyroid gland was removed from one of each pair and the other kept as a control.

When the operation was performed from three to four weeks after birth, marked stunting resulted ; in more than one instance the weight of the control was three times that, of the cretin.

Where thyroidectomy was delayed till the third or fourth month the retardation in growth was only slight; in some cases, indeed, no effect was evident although other signs of athyroidism were present.

In triplet goat kids, all females, the thyroids were removed from two when twenty days old, while the third was kept as a control. A difference in growth rate was detectable on the 19th day following operation, and from that time the normal rapidly outgrew the cretins.

There is no evidence for the belief that the mother's milk can retard to any extent the onset of hypothyroid symptoms in lambs or goat kids.

I wish to acknowledge my indebtedness to Miss E. Campbell, Dr A. Bodansky, and Dr H. S. Liddell, for assistance rendered in this investigation.

The expenses incurred were defrayed by grants received from the Heckscher Research Foundation of Cornell University, and the Sage Research Fund of the Ithaca Division of Cornell University Medical College.