To reduce the cost of pork production, high-fiber ingredients are often used in diets, but an increase in the amount of dietary fiber in pig diets may have a negative impact on the digestibility of nutrients and energy. Carbon footprint from pork production is related to emissions of greenhouse gases including carbon dioxide, nitrous oxide, and methane from pigs. Emission of gases may be correlated with the composition of feeds, and it is thus possible that feeding pigs with diets containing high-fibrous feed ingredients affects the gas exchange, which also impacts concentration of net energy (NE) in diets.

Therefore, the objective of this experiment was to test the null hypothesis that feeding pigs with a high-fiber diet does not affect gas production, N excretion, and NE in diets fed to group-housed pigs.

Stein, Hans H., Cristhiam J. Munoz, and Su A Lee. 2023. Factors affecting net energy values of diets fed to group housed and ad libitum fed growing pigs. XXXVIII Curso de especializacion FEDNA. Pag 213 - 223. Link to full text.

Rodriguez, Diego A., Su A Lee, Hans H. Stein. 2023. Concentration of Net Energy in Corn without or with Microbial Phytase Fed to Group-Housed Pigs. J. Anim. Sci. Volume 101, Issue Supplement 2, Pages 151–152, doi.org/10.1093/jas/skad341.169. 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.

Corn is the primary grain used in pig diets and provides most energy to the diets. Because energy is the most expensive component in diet formulation, it is critical to accurately determine energy concentrations in corn. Use of exogenous phytase in pig diets has been a standard and most phytase is expected to generate extra-phosphoric effects that result in increases in minerals, amino acid, or energy digestibility. Therefore, phytase companies have provided customers with matrix values that can be used for down specs of energy and nutrients in diet formulation. It is thus important to confirm if dietary phytase releases energy and other nutrients as suggested before using them. To our knowledge, however, there is no information on how much phytase can increase net energy (NE) in corn when fed to group-housed pigs. Therefore, the objective of this experiment was to test the hypothesis that addition of microbial phytase to a corn-based diet increased the apparent total tract digestibility (ATTD) of gross energy (GE) and concentration of NE by group-housed growing pigs.

Lee, Su A, Diego A. Rodriguez, Hans H. Stein. 2022. Effects of Different Watering Options on Standardized Ileal Digestibility of Amino Acids and net Energy in Diets fed to Growing Pigs. J. Anim. Sci. 100, (Suppl. 3) 118, doi.org/10.1093/jas/skac247.227. Link to full text.

Depending on how facility allows pigs to drink water, considerable amounts of feeds can be wasted, which may affect digestibility of nutrients by pigs. Therefore, the objective of this experiment was to test the hypothesis that different watering options affect concentration of net energy (NE) in a corn-soybean meal diet fed to growing pigs.

Soybean meal (SBM) is the major source of amino acids in diets for swine throughout the world. However, in addition to providing indispensable amino acids to diets, SBM also provides energy to the diets. Diets are often formulated based on the net energy (NE) in each individual ingredient using a linear programming computer software. Therefore, the NE for each ingredient is important for the value the ingredient is assigned in the formulation. However, the NE for SBM that is used by most feed formulators was generated many years ago, but results of recent research indicate that current U.S. SBM may provide more NE than previously estimated, which potentially results in an increased estimation of the value of SBM in diets for pigs. There is, therefore, a need for confirming or updating the NE value for SBM. As a consequence, the objective of this experiment was to test the hypothesis that the NE in U.S. SBM fed to modern genotypes of pigs is greater than the value that is currently used in feed formulation.

Muñoz Cristhiam J., Hans H Stein. 2019. PSIV-11 Description of a novel Calorimetric unit to determine net energy in group housed pigs. Journal of Animal Science, Volume 97, Issue Supplement_2, July 2019, Pages 178–179. (Abstr.). Link to abstract.