Effects of supplementation with Aspergillus oryzae derived phytase (Ronozyme® HiPhos) and fiber degrading enzymes (Victus™ Swine Starter) on growth performance, intestinal morphology, leukocyte differential, and nutrient digestibility in nursery pigs

Abstract Text:

Pigs (n=264; PIC C-29 x 380) were blocked by BW (6.06±0.49 kg) and gender and allotted to 40 pens, each randomly assigned to one of four dietary treatments: 1) nutrient adequate corn-SBM-based diet meeting the P requirement using 400 FYT/kg of Ronozyme®HiPhos 2700 GT (DSM Nutritional Products, Inc., Parsippany, NJ) phytase (CTL); 2) as CTL, with 600 FYT/kg HiPhos added (total 1000 FYT/kg HiPhos, HiP); 3) as CTL, with 0.05% Victus-Swine-Starter (β-glucanase, xylanase, hemicellulose, polygalacturonase, α-amylase) added (VSS); and 4) as HiP with 0.05% Victus-Swine-Starter added (HPVS). TiO₂ was included (0.3%) in all diets fed throughout 3 diet phases (9, 14 and 14 d for phase 1, 2, and 3, respectively). On d 12, a median BW pig in each pen was administered fluorescein-isothiocyanate Dextran (3-5 kDa; FD) via oral gavage followed by blood collection 3 h later to determine FD absorption, and a subsample was obtained to measure leukocyte differentials. On d 13, duodenal and jejunal samples were obtained from the FD-treated pigs to evaluate intestinal morphology. Fecal samples were obtained at the end of phases 2 & 3 to determine ATTD of ash, P and Ca, and STTD of P was calculated using the equation from NRC 2012. Overall, ADG, ADFI, G:F, and final BW were similar among CTL-, HiP-, VSS-, or HPVS-fed pigs . Villus height, crypt depth, and villus height to crypt depth in both duodenum and jejunum were not different. However, plasma FD (1.19, 1.74, 2.47, 2.34µg/mL; P=0.05) and percentage lymphocytes (32.3, 38.5, 38.2, and 44.2%; P<0.05) increased, while the percentage neutrophil (54.2, 52.6, 46.7, and 44.9%; P<0.05) and neutrophil to lymphocyte ratio (195.8, 143.3, 129.3, and 108.8%; P=0.02) decreased, in pigs fed HPVS compared to CTL, with those fed HiP or VSS being intermediate. In phase 2, HiP- and HPVS-fed pigs had higher STTD P than CTL- and VSS-fed pigs (62, 66.1, 61.3, 67.8%; P<0.01). For phase 3, ATTD of ash (91.2, 92.5, 92.3, 92.7%; P<0.01) and STTD of P (84.8, 88.5, 86.1, 89.8%; P<0.01) were higher in HiP- and VSS-fed pigs than CTL, with the highest STTD P observed in pigs fed HPVS. Both VSS- and HPVS-fed pigs had increased ATTD Ca compared to CTL (86.1, 87.2, 88.1, 88.7%; P<0.05). Results of this study suggest that Victus-Swine-Starter and an increased level of HiPhos can modulate plasma levels of neutrophils and lymphocytes, and further improve nutrient digestibility in nursery pigs. 

Keywords:

Phytase, Fiber degrading enzymes, Nursery pigs.