Soybean meal (SBM) is referred to as the “gold” standard of protein; however, SBM also contains antinutritional factors that are known to hinder bird performance. Soybeans are toasted during SBM manufacture, but the optimal temperature and holding time for adequate processing is not well-defined. An initial companion experiment determined that including under-processed SBM in mash diets decreased bird performance. Therefore, diets containing under- and peak- processed SBM conditioned at 70, 80, or 900 for 30 s in addition to an over-processed SBM mash diet were assessed to determine optimal conditioning temperature via live bird performance and amino acid digestibility. The three SBM types (under-, peak-, over-processed) were obtained from a commercial soybean crush plant. Diets were formulated to 85% crude protein and digestible amino acid requirement, differing only in the type of SBM utilized. Diets were fed for 18 days and contrasts were performed to explore differences between treatments. A 2 (SBM type) × 3 (Conditioning temperature) factorial was analyzed for the pelleted diets. The 7 diets were each fed to 12 replicate cages of 9 chicks. On day 18, live performance metrics were measured, and ileal contents were collected. Day 0- 18 feed intake (FI) per bird increased with increasing conditioning temperature (P<0.05). An interaction between SBM type and conditioning temperature was identified, wherein birds fed the under-processed SBM diet gained more weight with increasing conditioning temperature while live weight gain (LWG) decreased for the peak-processed diet (P<0.05). Increasing the conditioning temperature of the under-processed diet to 800 restored LWG to that of the peak-processed 700 diet. Feed conversion ratio (FCR) was increased in the peak-processed diet and decreased by the under-processed diets with increasing conditioning temperature (P<0.05). Birds fed the over-processed diet gained the least and had the lowest FI (P<0.05). The digestibility of all amino acids increased when the conditioning temperature of the under-processed diet increased from 700 to 800 (P<0.05) and did not change for the peak-processed diets. Diets containing under- processed SBM conditioned above 700C and pelleted mitigated antinutritional performance effects.

Adejumo, R., K. Bowen, L. Knarr, E. Lynch, E. Estanich, A. Renner, T.  Waugerman, H. Krishnan and J. Moritz. 2025. Conditioning above 700C and Pelleting Corn and Soybean Meal-based Diets Containing Under Processed Soybean Meal can Alleviate the Effects of Antinutritional Factors. 2025 International Poultry Scientific Forum, Abstract M139.