In 1906 an experiment was begun at the Wisconsin Experiment Station which had a far-reaching effect on the minds of students of nutrition. It was planned by S. M. Babcock, and was carried out by Hart and Humphrey, with the later co-operation of Steenbock and the author. In this experiment the object was to determine whether rations for cattle so made up as to be alike insofar as could be determined by chemical analysis, but derived each from a single plant, would prove to be of equal nutritive value for growth and the maintenance of vigor (4).

The ration employed for one group of animals was derived solely from the wheat plant, and consisted of wheat straw, wheat gluten and the entire wheat grain. The ration of a second group consisted of the entire corn plant, which included the kernel, stalk, and the leaf, together with a portion of corn gluten, a byproduct of the cornstarch industry. The third group obtained their ration solely from the oat plant, being fed entirely on rolled oats and oat straw and leaf. There was a fourth group, which it was supposed would serve as controls, that was fed a ration having the same chemical composition, but derived from about equal portions of wheat, corn and oat products.

The animals employed were young heifer calves weighing about 350 pounds, and were as nearly comparable in size and vigor as could be secured. They were restricted absolutely to the experimental ration. They were given all the salt (NaCl) they cared to eat, were well cared for, and were allowed to exercise in an open lot free from vegetation. Their behavior during growth and during the performance of the functions of reproduction were extremely interesting. All groups ate practically the same amounts of feed and digestion tests showed that there were no differences in the digestibility of the three rations.