Effect of phytase on true total tract digestibility of phosphorus in full-fat rice bran determined in pigs by regression method

The goal of this study was to determine the effect of phytase on true total tract digestibility of phosphorus (TTDP) and endogenous losses of phosphorus (ELP) of full-fat rice bran (FFRB) by simple linear regression. Twelve castrated pigs in the growing phase with an average live weight of 57.00 +/- 2.50 kg were used. The experiment lasted 36 days, divided into three periods of 12 days each. The experimental design consisted of randomized blocks in a 2 x 3 factorial scheme, with two levels of fungal phytase (0 and 750 FTU kg(-1)) and three levels of phosphorus (P) coming from FFRB (5%, 10%, and 20%), totaling six treatments with six replicates. The P coming from FFRB recovered in feces was influenced by phytase (P < 0.008) and by the amount of ingested FFRB (P < 0.001). The average value of ELP was 524 mg/kg dry matter intake (DMI). The TTDP of FFRB was increased by 20 percentage points due to phytase addition. In conclusion, the ELP represented 524 mg/kg DMI on average. The addition of 750 FTU of phytase increased the TTDP of FFRB, which was 32.60% and 52.60% without and with phytase, respectively.