154 The Effect of a Novel Consensus Bacterial 6-Phytase Variant on Ileal Digestibility of Energy in Growing Pigs: Meta-Analysis of 4 Trials

Abstract

Abstract This meta-analysis evaluated the effect of a novel consensus bacterial 6-phytase variant (PhyG) on the apparent ileal digestibility (AID) of energy in growing pigs. It was hypothesized that increasing phytase doses improves energy digestibility. The database was constructed using 4 studies (PIC, L 800 × Camborough sows or TN Tempo × TN70 breeds; average body weight of 26.5 kg at sampling), contributing 220 data points. Pigs were fed corn or corn-wheat based diets with soybean meal, canola meal, rice bran, wheat middlings or DDGS. All studies had a negative control (NC) diet deficient in total Ca, dig P, standardized ileal digestible amino acids and without feed phosphates. The analyzed total Ca, total P, phytate P and calculated net energy ranged from 0.46 to 0.53%, 0.37 to 0.43%, 0.24 to 0.30%, and 2,441 to 2,472 kcal/kg, respectively. The NC was supplemented with PhyG at 250, 500, 1,000 or 2,000 FTU/kg. Digesta were collected using ileal T-cannulation (9-10 replicates/treatment, Latin square design). Data were analyzed using the Fit Model platform of JMP 14.0 with trial code as a random effect. Phytase dose response (using analyzed phytase activity) was analyzed with exponential curve fitting. The AID of gross energy and the ileal digestible energy (DE, kcal/kg) improved with 1,000 or 2,000 FTU/kg PhyG treatments vs. NC (P < 0.05, Table 1). Increasing the PhyG dose exponentially increased (P < 0.1) the AID of gross energy (%) and the ileal DE. Ileal DE improvement above NC increased exponentially (P < 0.06) up to 120.8 and 132.6 kcal/kg at 1,000 and 2,000 FTU/kg, respectively. In conclusion, PhyG supplementation improved ileal DE in growing pigs in a dose-dependent manner.