Marshall, Caleb M, Su A Lee, and Hans H. Stein. 2024. Interactive effects of extrusion and particle size reduction of corn on metabolizable energy by weanling pigs. J. Anim. Sci., Volume 102 (Suppl. 3): 261–262 (abstr.). doi.org/10.1093/jas/skae234.299 Link to abstract.

Ibagon, Jimena A., Su A Lee, Hans H. Stein, Martin Nyachoti. 2024. Reduction of particle size of field peas increases net energy and digestibility of starch when fed to growing pigs. J. Anim. Sci Vol. 102, Suppl. S2. P 97 - 98. doi.org/10.1093/jas/skae102.109 Link to abstract.

Extrusion results in increased digestibility of energy, which is primarily due to increased gelatinization of starch. Because this process improves flavor of cereal grains, it is known that extrusion improves palatability in pig diets. Particle size reduction in cereal grains results in an improved digestibility of nutrients due to increased surface area of grains, which subsequently increases the interaction with digestive enzymes. However, because grinding changes the textural traits of grains, the palatability of feeds is low and thus feed intake of pigs is often reduced.

The feed preference of pigs may be influenced by the characteristics of feed ingredients included in diets, but it is not known if different particle size of extruded corn affects the feed preference of weanling pigs. Therefore, the objective was to test the null hypothesis that there were no effects of reducing particle size of extruded corn on feed preference by weanling pigs.

Ibagon, Jimena A., Su A. Lee, C. Martin Nyachoti, and Hans H. Stein. 2024. Influence of particle size and origin of field peas on apparent ileal digestibility of starch and amino acids and standardized ileal digestibility of amino acids when fed to growing pigs. Translational Animal Science, 2024, 8, txae008. doi.org/10.1093/tas/txae008.

Lee, Su A., Diego A. Rodriguez, Hans H. Stein. 2023. Interactive Effects of Pelleting and Particle Size Reduction of Corn on Ileal Digestibility of Starch and Amino Acids in Corn-Soybean Meal Diets Fed to Pigs. J. Anim. Sci. Volume 101, Issue Supplement, Pages 186–187, doi.org/10.1093/jas/skad341.205. Link to abstract.

Lee, S. A., D. A. Rodriguez, C. B. Paulk, H. H. Stein. 2023. Effects of pelleting and particle size reduction of corn on digestibility of starch, amino acids, fibre and fat, and concentration of net energy in corn-soybean meal diets fed to group-housed pigs. Animal - science proceedings, Volume 14, Issue 7, Pages 857-858. doi: 10.1016/j.anscip.2023.09.041.

Field peas (Pisum sativum L.) have been cultivated for centuries for human consumption, due to the high nutritional quality of pea protein. However, during the last years, increasing demand for field peas for livestock feeding has developed a market in Canada, Europe, and the U.S. Therefore, as is the case with some feed ingredients, differences in soil, varieties, agronomic practices, and growing method may change the nutritional characteristics of the peas as well as the digestibility of nutrients. Besides that, differences in the particle size of field peas may change the digestibility of nutrients. Therefore, the objective of this experiment was to test the hypothesis that the standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA) in field peas is affected by the particle size of the field peas and the region where the field peas were grown.

Rojas, O. J. and H. H. Stein. 2017. Processing of ingredients and diets and effects on nutritional value for pigs. J. Anim. Sci. Biotechnol. 8:48. Link to full text

Casas, G. A., C. Huang, and H. H. Stein. 2017. Nutritional value of soy protein concentrate ground to different particle sizes and fed to pigs. J. Anim. Sci. 95:827-836. Link to full text (.pdf)