The effects of phytase on grower pig growth performance and ileal inositol phosphate degradation

Abstract

This experiment was conducted to assess the effects of a standard and a high dose of phytase (Quantum Blue) on grower pig growth performance and ileal inositol phosphate (InsP3–6) and myo-inositol (MYO) concentration. Throughout this 28 d study, 576 pigs (initial BW 17.3 kg) were fed 1 of 4 wheat–barley–soybean meal–based diets. Experimental diets comprised a high-P positive control (PC; 4.1 g digestible P [dig-P]/kg), a low-P negative control (NC; 2.8 g dig-P/kg), the NC + 500 phytase units (FTU)/kg, and the NC + 2,000 FTU/kg. Each diet was offered ad libitum to 16 pens of 9 mixed sex pigs. Pigs fed both phytase treatments had increased ADG (P < 0.01) and ADFI (P < 0.05) compared to pigs fed the NC and were similar to those fed the PC. Furthermore, phytase reduced the concentration of InsP6 and InsP5 (P < 0.001) at the terminal ileum but had no effect on InsP4 or InsP3 concentrations. The InsPx degradation patterns did not differ between the standard and high phytase treatments. In conclusion, phytase improved the growth performance of grower pigs fed a low-P diet; however, there were no differences between the 500 and 2,000 FTU/kg treatments in terms of growth performance, ileal InsP3–6 concentration, or MYO generation