I was back in Ann Arbor, Michigan recently, and found an old book – presumably my dad’s – up in the attic of the farmhouse in which I was raised. Called simply “Pork Production,” by William W. Smith, it was a “Centennial Gift Edition, Archer-Daniels-Midland Company, 1840…1940.”

It was fascinating to see how much the industry has changed between then and now. It truly represents a sea-change in how pigs are produced.

One section covered “Hogging-Off Corn and Other Crops.” According to the book, the practice of turning pigs into the cornfield when the grain was well-dented and allowing them to remain to harvest the crop, known as “hogging-down” or “hogging-off,” was a common practice. In fact, a little more than 11% of the corn acreage in the U.S. was harvest by this method in the late 1930s.

“For the latitude of the corn belt, the hogging-off season begins about Oct. 1 and ends thirty or forty days later,” the author wrote. “Usually the weather is not favorable for a longer season, although occasionally early fall pigs are kept in the field until after Christmas. Late farrowed spring pigs which have received a limited grain ration during the summer, which are thin and active, and of a weight from 90 to 140 lbs., are the kind generally available and most efficient for this work.”

Studies comparing yard-fed corn and tankage with hogging-off corn and tankage were performed, but keep in mind that yard-fed corn was still ear corn – it’s just the pigs didn’t need to harvest it themselves. And for those of you who don’t know what tankage is, the dictionary says “tankage is slaughterhouse waste from which the fat has been rendered in tanks: the residue is dried and ground for use as fertilizer or feed.” This product was later replaced by soybeans.

In most cases, the yard-fed hogs performed slightly better than the pigs in the field. The difference, in the average, amounted to 1.5 lbs. of pork for each bushel of corn fed, perhaps because the pigs were using more energy to find and eat the corn in the field.

Hogging-off corn saved labor “which would be required in husking, cribbing, and feeding,” Smith wrote, and their manure provided fertilizer, right where it was needed. If the crop was damaged or lodged, it was much easier to turn pigs out in it than to try to harvest it.

On the other hand, a considerable amount of corn was lost, and extra fencing was usually necessary. In addition, the “trampling and packing” by the pigs, especially in rainy seasons, compacted the soil. The practice of hogging-down corn also interfered with the common cropping system of planting winter wheat.

This undoubtedly was the first truly organic, pasture-raised pork!