Effects of Increased Nsp with Or Without Nspase Supplementation on Growth Performance, Intestinal Health, and Intestinal Microbiome of Nursery Pigs and Implications on Subsequent Phases of Production

Abstract This study aimed to investigate the effects of increased NSP from alternative feedstuffs in feeds with or without NSPase supplementation on growth performance, nutrient digestibility, intestinal health, immune status, and modulation of the intestinal microbiome of nursery pigs and the carryover effect from dietary nursery intervention on the subsequent phases of production. One hundred and sixty newly weaned pigs at 7.0 ± 0.3 kg BW were allotted in a 2 x 2 factorial arrangement with NSP level and NSPase supplementation serving as factors and sex as block. Pigs were assigned to one of 4 dietary treatments with the control having corn DDGS as the main source of NSP and HNSP having soy hulls and wheat bran replacing corn DDGS as the source of NSP. Pigs were fed for 37 d in 2 phases (19 d and 18 d, respectively) and housed in a pen of 4. Growth performance was measured at the end of each phase. At d 37, a pig representing the median BW within each pen from each treatment was euthanized for sampling jejunal mucosa, jejunal tissue, and ileal digesta to analyze intestinal health variables, oxidative stress products, and digesta viscosity. The remaining pigs were then fed a common diet for the subsequent grower and finisher phases to evaluate the carryover effect. At the end of the finisher phase, all pigs were euthanized to obtain carcass data. Data were analyzed using Mixed procedure of SAS 9.4. Overall, NSP level and type nor NSPase supplementation had an effect on growth performance; however, HNSP tended to have improved (P = 0.087) feed efficiency (0.52 to 0.53) in the grower period immediately following the nursery phase. Additionally, HNSP increased (P < 0.05) IgG (4.84 to 5.83 µg/mg of protein) in the jejunal mucosa and tended to increase (P = 0.096) the villus height in the jejunum (482.8 to 506.6 μm). The body weight of HNSP pigs was more uniform (P < 0.05; 8.7 to 11.6%) than the control at the end of the 120-day trial. No differences were observed in carcass traits however, the hot carcass weight of pigs in HNSP tended to be more uniform (P = 0.089; 6.4 to 10.00%) than the control. In conclusion, increased amounts of NSP from alternative feedstuffs does not further impair or damage the intestinal health and subsequent growth performance of nursery pigs and may aid the pig through generated metabolites and alterations to the intestinal microbiota as they are transitioned to the ensuing phases of production as evidenced by the increased uniformity at the end of the trial.