THYROID HYPERPLASIA AND THE RELATION OF 
IODINE TO THE HAIRLESS PIG MALADY. I.* 
By E. B. HART anp H. STEENBOCK. 
(From the Laboratory of Agricultural Chemistry of the University of 
Wisconsin, Madison.) 
PLATES 2 AND 3. 
(Received for publication, December 17, 1917.) 
In our early experimental inquiries! on the growth of swine we 
soon learned that restriction to any one grain and its protein con- 
centrate or a mixture of grains and seed protein concentrates 
would lead to nutritional failure. Growth would cease and evi- 
dences of serious malnutrition appear. It was found that cer- 
tain supplements to the grains must be made if physiological 
soundness was to be maintained and growth continued. Among 
- the efficient supplements were tankage, milk, or the leaf and stem 
portion of plants, such as alfalfa. The plant roughage or 
tankage was more efficient than milk, the latter ultimately fail- 
ing as a sole supplement to the grain for perfect nutrition in the 
proportion used and under strict confinement of the animals. We 
believe this failure of milk to rest solely on its quantitative rela- 
tion to the grain mixture and had enough been supplied, success 
would have followed. With other species of animals and milk as 
milk powder constituting 10 per cent of the dry matter of a 
grain ration, successful nutrition has been attained. 
After making clear what classes of materials must be used as 
supplements to the grains for successful growth,—without as yet 
having finished the problem as to the complete analysis of the 
factors for successful nutrition contributed by the supplements,— 
our animals were involved in reproduction. In anumber of cases 
* Published with the permission of the Director of the Wisconsin Agri- 
cultural Experiment Station. | 
1 Hart, E. B., and McCollum, E. V., J. Biol. Chem., 1914, xix, 373; 
Proc. Am. Soc. Animal Production, 1915, p. 49; J. Biol. Chem., 1916, xxiv, 
p. xxviii. Hart, E. B., Miller, W. S., and McCollum, E. V., zbid., 1916, 
Xxv, 239. 
313 
