EVALUATION OF ON-FARM PROCESSED FULL FAT SOYBEANS FOR USE IN PRACTICAL SWINE DIETS

On-farm processed full-fat soybeans (FFS) represent an alternative protein and energy source to soybean meal (SBM) in swine diets; however, their nutritional value depends on adequate thermal processing. This thesis evaluated the nutritional value of on-farm processed FFS and strategies to support their practical use in pig diets. Processing method markedly affected nutrient digestibility, with extruded FFS having greater standardized ileal digestibility of crude protein and amino acids and greater digestible energy than roasted FFS, while protease supplementation provided limited additional benefits. When FFS partially replaced SBM in feeding programs from weaning to slaughter, overall growth performance was maintained. Supplementing FFS-containing diets with a commercial postbiotic improved growth performance during nursery phase II, but these benefits did not persist during the grower and finisher periods. Carcass characteristics, belly firmness, and postmortem muscle pH were not affected by feeding regimen. Feed cost, carcass value, and income over feed cost (IOFC) did not differ statistically among treatments; however, IOFC was $4.70/pig greater for pigs fed FFS compared with SBM. Overall, these findings demonstrate that processing method is a major determinant of the nutritional value of on-farm processed FFS that should be considered during diet formulation, and on-farm processed FFS can partially replace SBM without reducing lifetime growth performance or carcass yield, while providing a cost-effective protein and energy source for swine production.