Regardless of the rather widespread development of feeding standards for fattening swine, there was in 1910 a manifest need for a more simple and effective method for practical field and feedlot feeding. This need stimulated the development of the free-choice system or standards of feeding, with or without modification, and also the perfection of the self-feeding practice. In this development emphasis was placed on capitalizing the appetite and feeding habits of swine, inasmuch as the appetite was found in controlled experiments to be a fairly accurate and reliable guide under most conditions of successful feeding.
Early isolated experiments, 1776 to 1910, with self-feeding and free-choice swine feeding had failed to establish any trustworthy principles of far reaching importance in the development of a better practice, all being of too short duration and not broadly enough organized and executed to catch the new vision. Later, after the significant researches at the Iowa Agricultural Experiment Station on free-choice and self feeding methods were well under way and had been widely published, a new era in pig feeding practice was established, not only in this country but abroad.
The practicability of these new methods of feeding has been thoroly proven in literally hundreds of controlled experiments here and in other countries.
Evvard, John Marcus
"A new feeding method and standards for fattening young swine,"
Research Bulletin (Iowa Agriculture and Home Economics Experiment Station): Vol. 9
, Article 1.
Available at: https://lib.dr.iastate.edu/researchbulletin/vol9/iss118/1