The experiments in pig feeding conducted during the summer and fall of 1906, reported in Bulletin No. 91 of this Station, showed that with 40-cent corn, the cost of producing 100 pounds gain on growing pigs, averaging 60 pounds in weight at the start, was lower with the ration of . corn alone on pasture than with any one of several mixed grain rations commonly fed in Iowa. There has so far been no definite experimental work reported to show the most profitable form in which em u should be fed to your-g pigs. While other stations have investigated some phases of the problem of preparing corn for hog feeding, the work has mostly been done with well grown hogs in short feeding periods of less than 100 days, and with only part of the feasible methods of preparation included in any one experiment. Most of this work has been done with hogs weighing 100 to 200 pounds at the beginning of the tests. The most extensive experiments so far reported indicate that less benefit is to be expected from grinding corn for young hogs than for old ones, but the relative effects of the rations on hogs of different ages is by no means definitely settled.