0
Soybean meal (SBM) is the main protein source in swine diets due to its high nutritional value and bioactive compounds. However, high SBM inclusion in nursery diets may impair intestinal function because of antinutritional factors.
Objective: This study evaluated the effects of increasing SBM levels in nursery and finishing pig diets on growth performance, faecal characteristics, and carcass traits.
Methods: Six feeding trials were conducted to evaluate increasing dietary SBM inclusion during the nursery, grower, and finishing phases. A total of 2,889 pigs were fed diets with graded SBM levels while maintaining similar energy and standardized ileal digestible amino acid contents. Growth performance, feed efficiency, faecal dry matter (nursery), and carcass characteristics (finishing) were measured.
Results: Increasing SBM inclusion in early nursery pigs (~10 kg) reduced average daily gain, feed intake, and final body weight, indicating that high SBM levels may negatively affect performance in younger pigs. In slightly heavier nursery pigs (~13.5 kg), increasing SBM mainly reduced feed intake, with no effects on growth rate or feed efficiency. During the grower phase (~43 kg), higher SBM inclusion improved growth performance and feed efficiency in corn-based diets. However, when diets contained DDGS, increasing SBM levels did not further improve performance. In late-finishing pigs (~102 kg), SBM inclusion level had no effect on growth performance or carcass characteristics, regardless of whether diets were corn- or DDGS-based.
Conclusion: The optimal SBM inclusion level depends on the production stage and diet composition. Higher SBM inclusion impaired performance in young nursery pigs, improved growth efficiency during the grower phase, and had minimal effects during late finishing.
Faccin JEG, Arroyave J, Goodband RD, Tokach MD, DeRouchey JM, Woodworth JC, Gaffield KN, Gebhardt JT, Krishnan HB. Effects of increasing soybean meal in late nursery, grower, and finishing pig diets. Translational Animal Science; 2026: 10: txag082. https://doi.org/10.1093/tas/txag082