322 Hairless Pig Malady. I 
feeds, combined in different proportions and fortified with protein 
concentrates lead to the production of hairless pigs. 
We are of the opinion, for the present at least, that we have 
not reached the stage where it is wise to advocate the general use 
of iodine in the feed of all brood sows; that the conditions lead- 
ing to the production of hairless pigs should first be analyzed 
fully in order that we may acquire a complete understanding of 
the reasons for the successful rearing of. sows intended for breed- 
ing purposes through the use of natural materials, unfortified with 
potassium iodide. | 
However, in regions and on farms where hairless pig produc- 
tion is ongonie or persistent in character the direct use of iodides 
should be made. 
In the historical, as well as the practical phases of goiter pre- 
 yention some observations by Marine are of interest. He says:° 
‘‘The first instance of preventing goiter on a large scale was accidental 
and in connection with the sheep raising industry of Michigan. Prior to. 
the discovery of salt deposits around the Great Lakes, the future of the 
industry seemed hopeless, but with the development of the salt industry 
and its use by the sheep growers, goiter rapidly decreased. The salt con- 
tains appreciable quantities of both bromine and iodine. . . . . The 
second instance of goiter prevention on a large scale was in brook trout. 
Some years ago the development of goiter in artificially raised members 
of the salmon family became alarming and many plants were abandoned 
on account of the disease. After considerable work, which led to the con- 
clusion that. the disease was simple goiter, we were able to completely 
prevent the disease in several hatcheries, by the use of very small amounts 
of tincture of iodine added to the water.”’ Fs) 
It is therefore to be expected, that with the elucidation of the 
cause of the hairless pig malady, a prompt remedy, when neces- 
sary, can be applied. 
, 
EXPLANATION OF PLATES. 
PLATE 2. 
Fig. 1. Dead and hairless pigs. Note the thick necks, indicating a 
goitrous condition. The mother of these pigs had been reared on a high 
protein and low roughage diet, consisting of 15 parts of alfalfa, 25 of corn, 
25 of oats, 25 of middlings, and 10 of oil meal, and kept under strict con- 
finement. She had produced two litters of hairless pigs before being 
changed to a ration of 33 parts of clover, 33 of corn, and 33 of oats, on. 
which the above pigs were produced. 
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