Animal nutritionists have long known that plant-based protein sources are less expensive for swine feed rations.
But until recently they’ve worried over some anti-nutritional factors that can negatively affect gut health and growth performance in weanling pigs.
Recent research from the University of Illinois has shown that soy protein concentrate (SPC) may be partly or fully substituted for animal protein with no adverse effects.
“We determined digestibility of crude protein, amino acids, and energy in SPC ground to three particle sizes,” Hans H. Stein, an animal sciences professor said. “We also investigated the effects of substituting SPC for animal proteins on weanling growth performance.”
Read Also

Mazergroup’s Bob Mazer dies
Mazergroup’s Bob Mazer, who helped grow his family’s company into a string of farm equipment dealerships and the main dealer for New Holland machinery in Saskatchewan and Manitoba, died July 6 from cancer.
Soy protein concentrate is derived from defatted soy flakes by removing soluble carbohydrates and other non-proteins.
In the group’s first experiment, pigs were fed diets containing soybean meal, fish meal, or SPC ground to one of three particle sizes.
Diets with SPC more finely ground had greater crude protein digestibility than the traditional protein sources.
In a second experiment, weanling pigs were fed corn mixed with each of the protein sources used in the first experiment. The goal was to measure apparent total tract digestibility of gross energy and the digestible and metabolizable energy in each diet. Again the SPC diets performed well, especially at finer particle sizes.
“Results of this experiment indicated that diets based on soybean meal and SPC can be fed to weanling pigs without negative effects on growth performance during the initial four weeks after weaning,” Stein said.