Two experiments were conducted to evaluate the effects of fermentable protein (FP) on pig health and performance. FP is defined as the difference in ATTD CP and AID CP on a total CP basis. In experiment 1, 1,449 pigs (~19 d of age; initial BW = 5.9 ± 0.2 kg, 16 reps/trt, 22-23 pigs/pen) were blocked by pen location and randomly assigned to one of 4 treatments with FP levels of 1.36, 1.26, 1.16, and 1.06 in phase 1 (d 0-11) and phase 2 (d 11-20.5). FP was decreased primarily through the addition of soy protein concentrate (SPC) and the reduction of soybean meal (SBM). In experiment 2, 144 pigs (~21 d of age; initial BW = 4.7 ± 0.7 kg, 8 reps/trt, 3 pigs/pen) were blocked by weight and randomly allotted to one of 6 treatments with FP levels of 1.30, 1.24, 1.20, 1.15, 1.11, and 1.07 for phase 1 (d 0-7) and 1.22, 1.17, 1.13, 1.08, 1.03, and 0.99 for phase 2 (d 7–21). FP was decreased through the incremental replacement of soybean meal with hydrothermal mechanical processed (HTM) SBM. For both experiments, performance data was analyzed as a general linear model. Mortality and removal (M&R) and stool quality were analyzed as generalized linear mixed models, with a binomial or multinomial distribution, respectively. For experiment 1 (Table 1), the reduction in FP with SPC increased ADFI, decreased gain:feed, and reduced the probability of M&R from trial. For experiment 2 (Table 2), reduction of FP with HTM SBM linearly increased ADG, gain:feed, and probability of visually observing a more normal stool. A quadratic effect of reducing FP was also detected for ADG and ADFI.
In conclusion, these two experiments highlight that reducing diet FP can influence health and performance of pigs.