That the production of pork is an important factor on the average farm in Iowa is well substantiated by the fact that the farmers or Iowa annually receive more money from the production of pork than do the farmers of any other two states in the Union. Furthermore the importance of this industry is well demonstrated in the fact that out of the total number of hogs received at the Union Stock Yards, Chicago, the greatest hog market in the world, Iowa furnishes more than fifty per cent. Recognizing these facts, we can readily appreciate the value of any work furnishing reliable data giving new light in regard to the economical production of pork.