PSIII-18 Effects of HiPhorius and Ronozyme HiPhos on performance of nursery pigs

Abstract

Abstract The objective of this study was to evaluate the efficacy of the new phytase HiPhorius (encoded by a 6-phytase gene from Citrobacter braakii and expressed from Aspergillus oryzae; dsm-firmenich) compared with Ronozyme HiPhos (a 6-phytase product produced with a genetically modified strain of the filamentous fungus Aspergillus oryzae; dsm-firmenich) on performance of nursery pigs. A total of 528 weaned pigs [PIC Camborough female × PIC 337 boar; 19 d of age, initial body weight (BW) = 6.5 kg] were blocked by initial BW and gender and allotted to 48 pens which were randomly assigned to 1 of 4 dietary treatments (10 to 12 pigs/pen; 12 pens/treatment), including T1) Ronozyme HiPhos 3,000 FYT/kg, T2) HiPhorius 1,000 FYT/kg, T3) HiPhorius 1,500 FYT/kg, and T4) HiPhorius 2,000 FYT/kg. Pigs were fed a 3-phase feed-budget program, consisting of 1.4 kg/pig in Phase 1, 5.5 kg/pig in Phase 2, and Phase 3 diets fed to d 42 postweaning. Diets were formulated to be isocaloric and contained 1.41, 1.34, and 1.27% SID Lys for phase 1, 2, and 3, respectively. Phytase levels were tested at the same dose in phase 1 and 2 diets, while in phase 3, phytase levels were tested at 2,000 and 1,000 FYT/kg, respectively, for the Ronozyme HiPhos and HiPhorius treatments. During d 0-15 and d 0-22, pigs fed HiPhorius 1000 had reduced (P < 0.05) feed conversion than Ronozyme HiPhos and HiPhorius 2000. No significant treatment effects were observed on average daily gain (ADG) or average daily feed intake (ADFI) during these periods. During d 22-42, pigs fed HiPhorius 2,000 had greater ADG (P = 0.08), final BW (P = 0.09), and ADFI (P = 0.03) than HiPhorius 1,000 and Ronozyme HiPhos; however, there were no treatment effects on feed conversion. Overall (d 0 - 42), feeding HiPhorius 2,000 improved ADG compared with feeding Ronozyme HiPhos, HiPhorius 1,000, and HiPhorius 1,500 (476 vs. 458, 449, and 458 g, respectively; P = 0.07); however, similar ADFI and feed conversion were observed among treatments. Data from this study suggest that feeding HiPhorius at 2,000 FYT/kg provided greater ADG compared with feeding HiPhorius at reduced amounts or Ronozyme HiPhos. While the two sources of phytase had similar responses on nursery ADFI and feed conversion overall, feeding HiPhorius at 1,000 FYT/kg resulted in decreased feed conversion during the first 3 wk post-weaning.