PSVI-8 - Effects of reducing dietary fermentable protein by increasing levels of a hydrothermal mechanical processed soybean meal on growth performance and survivability of nursery pigs

Abstract: Inclusion of highly digestible proteins can reduce protein fermentation in the hindgut and improve gut health. This study evaluated the effects of reducing dietary fermentable protein (FP) by increasing levels of a hydrothermal mechanical processed (HTM) soybean meal (Provisoy^TM, Cargill, USA), optimized for protein digestibility, as a replacement for soybean meal (SBM) on growth performance and health of nursery pigs. In total, 1,840 weaned pigs [6.5 ± 0.1 kg initial body weight (BW)] were allotted to 20 replicate pens per treatment (23 pigs per pen) in 2 barns. Pens were blocked by location within barn and randomly allotted to 4 treatments with 0, 6, 12, and 18% HTM SBM in phase 1 (d 0-10) and 0, 3, 6, and 9% HTM SBM in phase 2 (d 10-23). A low complexity basal diet with 27 and 31% conventional SBM in phase 1 and phase 2, respectively was used. The HTM was added at the expense of conventional SBM to reach the desired HTM treatment levels while maintaining digestible lysine concentrations. All pigs were fed a common phase 3 diet from d 23-39 post-weaning. 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 as well as pen scouring were analyzed as generalized linear mixed models, with a binomial distribution. Contrasts were used to evaluate the linear and quadratic effect of increased dietary inclusion of HTM SBM. Results indicate that reducing FP by increasing HTM SBM levels did not impact overall average daily gain, average daily feed intake, or final body weight. However, dietary FP tended (P < 0.10) to linearly improve gain:feed from day 0-10 post-weaning as FP decreased but not impact overall gain:feed. In addition, as FP decreased, overall mortality tended (P < 0.10) to decrease linearly and pen scouring was numerically reduced on d 3 and d 6 post-weaning when compared to pigs fed conventional SBM. In conclusion, reducing dietary fermentable protein, by increasing HTM SBM may influence survivability of nursery pigs.