Thyroid Hyperplasia and the Relation of Iodine to the Hairless Pig Malady. I.*

In our early experimental inquiries1 on the growth of swine we soon learned that restriction to any one grain and its protein concentrate or a mixture of grains and seed protein concentrates would lead to nutritional failure. Growth would cease and evidences of serious malnutrition appear. It was found that certain 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 failing 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 relation to the grain mixture and had enough been supplied, success would have followed. With other species of animals and milk as mitk 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 a number of cases