Rojas, O. J. and H. H. Stein. 2014. Effects of reducing the particle size of corn on growth performance and carcass characteristics of growing-finishing pigs. J. Anim. Sci. 92(Suppl. 2):52 (Abstr.) Link to abstract (.pdf)

Rojas, O. J., Y. Liu, and H. H. Stein. 2013. Phosphorus digestibility and concentration of digestible and metabolizable energy in corn, corn coproducts, and bakery meal fed to growing pigs. J. Anim. Sci. 91:5326-5335. Link to full text (.pdf)

Grinding of feedstuffs to small particle sizes is a low-cost way to increase their energy and nutrient digestibility. Currently, nutritionists recommend feeding corn ground to an average particle size of 650 to 700 µm. However, it may be advisable to formulate diets containing corn ground to smaller particle sizes due to the greater metabolizable energy (ME) values of these diets. A previous experiment conducted by Rojas and Stein at the University of Illinois demonstrated that when diets are formulated to contain the same amount of metabolizable energy, feeding diets containing corn ground to different sizes to weanling pigs did not have a negative effect on growth performance.

An experiment was conducted to test the hypothesis that when diets are not adjusted to contain equivalent amounts of metabolizable energy, weanling pigs fed diets containing corn ground to smaller particles sizes will have an improved gain to feed ratio relative to pigs fed corn containing corn ground to larger particle sizes.

Lee, J. W., D. Y. Kil, B. D. Keever, J. Killefer, F. K. McKeith, R. C. Sulabo, and H. H. Stein. 2013. Carcass fat quality of pigs is not improved by adding corn germ, beef tallow, palm kernel oil, or glycerol to finishing diets containing distillers dried grains with solubles. J. Anim. Sci. 91:2426-2437. Link to full text (.pdf)

Rojas, O. J. and H. H. Stein. 2013. Phosphorus digestibility and concentration of digestible and metabolizable energy in corn, corn co-products, and bakery meal fed to pigs. J. Anim. Sci. 91(Suppl. 2):122 (Abstr.) Link to abstract (.pdf)

Kil, D. Y. and H. H. Stein. 2011. Dietary soybean oil and choice white grease improve apparent ileal digestibility of amino acids in swine diets containing corn, soybean meal, and distillers dried grains with solubles. Rev. Colomb. Cienc. Pecu. 24:248-253. Link to full text (.pdf)

By Dr. Hans H. Stein

December, 2010

It is well known that corn needs to be ground to be effectively utilized by pigs. For many years it has been common practice to recommend grinding to an average particle size between 650 and 700 microns. This particle size was based on research showing that if grain is ground to a smaller particle size, then problems with ulcers in pigs may increase.

Most corn hybrids grown in the US are genetically modified to resist certain pests or to tolerate certain herbicides. Numerous studies have been conducted to determine the nutritional value of corn that is genetically modified for pest resistance, but there are no published reports about feeding corn that has been modified for both pest resistance and insecticide tolerance to pigs. Investigation into the nutritional value of such corn is, however, warranted, because the use of crops with multiply stacked traits is rapidly increasing; approximately 35 million acres of crops with double- and triple-stacked traits were planted in the United States in 2006.

Two experiments were, therefore, conducted to determine if the nutritional value of corn grain with multiple genetically modified traits is different from that of nontransgenic corn. The hypothesis in both experiments was that pigs fed transgenic corn would not differ in growth performance or carcass characteristics from pigs fed nontransgenic corn.

Kil, D. Y., F. Ji, R. B. Hinson, A. D. Beaulieu, L. L. Stewart, G. L. Allee, J. F. Patience, J. E. Pettigrew, and H. H. Stein. 2009. Effects of dietary lipids on net energy of corn in diets fed to growing and finishing pigs. J. Anim. Sci. 87 (E-Suppl. 3):98-99 (Abstr.) Link to abstract (.pdf)