Source: Iain Hoey, Pigworld, 26 October 2020, photo credit: Bakingbusiness.co
Extrusion is the norm in the pet and aqua feed industries, yet it remains unusual for swine feed in the United States. But the technology can improve energy and protein digestibility in pigs, according to research from the University of Illinois.
“We’re not doing this much in the U.S., partly because the extrusion equipment typically is not installed in feed mills producing pig feeds. If a feed company decided they wanted to extrude diets or extrude grain by itself, as we did in this case, it would add cost. So the only way it would be economical would be if the pigs performed better with extruded grains,” says Hans H. Stein, professor in the Department of Animal Sciences and the Division of Nutritional Sciences at Illinois and co-author on a study in Animal Feed Science and Technology.
Stein and his research team compared pig diets containing either extruded or unprocessed corn, wheat, and sorghum to determine ileal starch and amino acid digestibility, as well as total tract digestibility of energy and fiber. One source of each grain was ground and then divided in two batches, with one batch left as is and the other extruded in a single-screw extruder with an exit temperature of 100 degrees Celsius. Grains were ground and extruded at Kansas State University, but extrusion equipment at the new Feed Technology Center at Illinois will facilitate future research to help meet the growing global demand for animal protein.