An experiment was conducted to evaluate various further processed soy protein sources on growth performance of nursery pigs. The sources evaluated included a hydrothermal mechanical processed (HTM) SBM (ProvisoyTM, Cargill, USA), an enzymatically modified (ENZ) SBM, a fermented (FM) SBM, and a soy protein concentrate (SPC). In total, 1,840 weaned pigs [6.4 ± 0.2 kg initial body weight (BW)] were allotted to 18 replicate pens per treatment (23 pigs per pen) in 2 barns. Pens were blocked by location within barn and randomly allotted to 4 treatments (HTM, ENZ, FM, and SPC). A low complexity diet with 22.5 and 30% conventional SBM in phase 1 (d 0-10) and 2 (d 10-22), respectively, and limited inclusion of highly digestible protein ingredients and health promoting additives was used as the basal diet. Soybean meal and SID Lys levels were constant across diets within phases by adjusting the levels of HTM, ENZ, FM, and SPC. Pigs were fed a common phase 3 diet during the last phase (d 22-39). Pig and feed weights were recorded at the beginning and end of each phase. Data were analyzed using the lme4 package of R 4.1.2, and the statistical model included the fixed effect of treatment, as well as the random effects of barn and location within barn. Mortality and removals were analyzed as generalized linear mixed models, with a binomial distribution. Contrasts were used to evaluate the effects of HTM vs ENZ, HTM vs FM, and HTM vs SPC. Results indicate that overall body weight, average daily gain, and average daily feed intake did not differ among treatments, but HTM tended to improve (P < 0.10) overall gain:feed compared to SPC and numerically reduced mortality and removals by 1.7% compared to FM. In conclusion, in a low complexity diet, pigs fed further processed soy protein, regardless of source, ended the trial with similar growth performance. However, feeding HTM resulted in numerically lower mortality and removals compared to FM.

May, S., M. Barnett and C. Pilcher. 2025. Evaluation of further processed soy protein sources on growth performance of nursery pigs fed a low complexity diet. 2025 American Society of Animal Science Midwest Section meeting, Abstract 23.