PSI-11 Standardized total tract digestibility of phosphorus in high-protein sunflower meal fed to growing pigs with or without phytase supplementation

Abstract

The objective of this research was to estimate the apparent (ATTD) and standardized (STTD) total tract digestibility of phosphorus (P) in high-protein sunflower meal (HP-SFM) fed to growing pigs with or without phytase supplementation. Twenty-four individually-housed pigs (19.5 ± 1.9 kg) were assigned to 1 of 4 diets in a completely randomized design to give 6 replicates per diet. The experimental diets consisted of a corn-soybean meal-based basal diet and a diet containing 30% of HP-SFM, both of which were fed without or with phytase supplementation at 500 phytase units/kg. Pigs were given their daily feed allowance at 2.8 times the maintenance energy requirement. The experimental period lasted for 15 d including 10 d for adaptation to experimental diets and 5 d for total collection of feces. The STTD of P was calculated by correcting the ATTD of P with the basal endogenous P loss, which was assumed to be 190 mg/kg dry matter intake. Phytase supplementation decreased (P < 0.05) both calcium (Ca; 1.34 vs. 2.14%) and P concentrations in feces (3.23 vs. 4.44%) in HP-SFM including diets. Addition of dietary phytase to the HP-SFM-contained diets also reduced (P < 0.05) daily Ca output from 3.08 to 1.86 g/d and daily P output from 6.41 to 4.51 g/d. The ATTD of Ca and P and STTD of P increased (P < 0.05) by providing phytase in both basal and HP-SFM including diets. The ATTD and STTD of P in HP-SFM were 18.4 and 19.3% for without phytase and 36.5 and 37.5% for with phytase, respectively, and there was a tendency (P = 0.063) for phytase supplementation to increase P utilization in HP-SFM fed to growing pigs. The standardized total tract digestible P content in HP-SFM was calculated at 3.61 g/kg.