316 Hairless Pig Malady. I 
EXPERIMENTAL. 
After our early experiments on the growth of swine with grains 
and grain mixtures had demonstrated the incompleteness of such 
rations and their disturbing influence on reproduction, attempts 
were made to determine the amount of alfalfa that must be intro- 
duced into the ration to secure a complete cycle of life. With 15 
per cent of the air-dried ration, as air-dried alfalfa, good growth 
and reproduction were secured. This particular ration consisted 
of 25 parts of corn meal, 25 parts of oat meal, 25 parts of wheat 
middlings, 10 parts of oil meal, and 15 parts of alfalfa. The pigs 
were strictly confined to the ration in pens 9 by 12 feet, with 
shavings as litter. They grew well, but their first litters of pigs 
were born dead and hairless. The hairless pigs were of normal 
weight and size and were generally carried a little over the full 
gestation time,—4 to 7 days. If born alive they lived a few hours 
after birth, but always died sooner or later. ‘Shey are charac- 
terized by thick pulpy necks and thick skin infiltrated with mucin 
material. The hair coat may vary and appears to bear a particu- 
lar relation to their vitality. Where hairless, the skin is smooth, 
shiny and bald, except for a few hairs around the eyes and nose. 
In the same litter there may be variation from full hair coats 
with full vigor to the scanty hair coats and little vitality. The 
hoofs of hairless pigs are thin walled and undeveloped and the 
thyroid gland is greatly enlarged. . 
In our experience the fresh weight of the thyroid from hairless 
new-born pigs may vary from 0.5 to 3.5 gm., while the fresh 
weight of the thyroid from the normal new-born pig is rarely 
over 0.3 gm. It is difficult to state just what a normal thyroid 
is, for there is considerable variation in weight in the thyroids 
from apparently normal pigs, but in the 50 to 60 thyroids which 
we have examined from normal 1 day old pigs the fresh weight 
varied from 0.160 to 0.800 gm. 
The thyroid of sows producing normal pigs also varies in size, 
and sows of 300 pounds’ live weight may have fresh thyroids 
varying in weights of from 20 to 50 gm. The thyroid of sows 
producing hairless pigs is likewise large and may weigh 125 gm. 
in the fresh state. In our experience there is not complete invo- 
lution, through the administration of potassium iodide, of the 
