Figure 5.

Predicted effect of graded concentrations of phytate P (x) and log doses of phytase (v) on gizzard inositol concentration (µ mol/g) of 21-day-old broilers. Inositol concentration was predicted with the equation: y = − 291 + 2,179x − 3,546x² + 237v − 52.9v² − 1,721xv + 2,902x²v + 385xv² − 648x²v², adjusted R²=0.87, RMSE=1.69, P < 0.0001. The predicted maximum inositol concentration in the gizzard was achieved at 2,000 phytase units (FTU)/kg in broilers fed diets containing 0.24 or 0.345% phytate P or 202 FTU/kg in broilers fed 0.45% phytate P. In the absence of phytase, the predicted concentration of inositol in the gizzard was 19.6, 28.1, or 25.9 µ mol/g, respectively.