Effects of adding high‐dosing Aspergillus oryzae phytase to corn–wheat–soybean meal‐based basal diet on growth performance, nutrient digestibility, faecal gas emission, carcass traits and meat quality in growing‐finishing pigs

This study tests the effects of supplementation of high‐dosing Aspergillus oryzae phytase into the corn–wheat–soybean meal (SBM)‐based basal diet on growth performance, nutrient digestibility, faecal gas emission, carcass traits and meat quality in growing‐finishing pigs (29.73–110.86 kg live weight; 70‐day‐old to 166‐day‐old). A total of 56 crossbred pigs [(Landrace × Yorkshire) × Duroc] were divided into two dietary groups for a 96‐day experiment (growing period, days 0–42; finishing period, days 43–96) with a completely randomized block design. There were seven replicate pens in each dietary group, and each pen has four pigs (two barrows and two gilts). The dietary treatments consisted of a corn–wheat–SBM‐based nutrient sufficient basal diet or the basal diet supplemented with 1500 FTU/kg A. oryzae phytase. One phytase unit (FTU) was defined as the amount of enzyme that catalyses the release of one micromole phosphate from phytate/min at 37°C and pH 5.5. Higher average daily gain and lower feed conversion ratio were observed in growing‐finishing pigs consuming a high‐dosing A. oryzae phytase supplementing diet during days 0–42 and 0–96. Supplementing high‐dosing A. oryzae phytase to the diet of growing‐finishing pigs increased apparent total tract digestibility of phosphorus on days 42 and 96. Moreover, growing‐finishing pigs fed the diet supplemented with high‐dosing A. oryzae phytase had higher carcass back‐fat thickness than those fed the control diet. However, the faecal gas emission and meat quality were not affected by high‐dosing A. oryzae phytase supplementation. In conclusion, dietary supplementation of high‐dosing A. oryzae phytase (1500 FTU/kg) had beneficial effects on the growth performance, apparent phosphorus digestibility and carcass back‐fat thickness in growing‐finishing pigs.