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 determine the coefficient of apparent (CATTD) and standardized total tract digestibility (CSTTD) of phosphorus (P) in high-protein sunflower meal (HP-SFM) fed to growing pigs with or without phytase supplementation. Twenty-four pigs (19.5 ± 1.9 kg) were assigned to 1 of 4 diets to give 6 replicates per diet. The experimental diets consisted of a corn-soybean meal-based diet and a diet containing 300 g/kg of HP-SFM, both of which were fed without or with phytase supplementation at 500 phytase units/kg. The CATTD and CSTTD of P in experimental diets were determined and then the CATTD and CSTTD of P in HP-SFM were calculated using the difference method. Pigs were fed their diets at approximately 2.8 times the maintenance energy requirement. Pigs were housed individually in metabolism crates for 15 days including 10 days for adaptation to experimental diets and 5 days for total collection of feces. Phytase supplementation decreased (P < 0.05) both calcium (Ca; 21.4 vs. 13.4 g/kg) and P (44.4 vs. 32.3 g/kg) concentrations in feces in HP-SFM-containing diets. The addition of dietary phytase to the HP-SFM-containing diets also reduced (P < 0.05) daily fecal Ca output from 3.08 to 1.86 g/day and daily fecal P output from 6.41 to 4.51 g/day. The CATTD of Ca and P and CSTTD of P increased (P < 0.05) with phytase supplementation in both basal and HP-SFM-containing diets. There was a tendency (P = 0.061) for phytase supplementation to increase P utilization in HP-SFM, and the CATTD and CSTTD of P in HP-SFM with phytase supplementation were 0.37 and 0.38, respectively, which were higher than for HP-SFM without phytase supplementation (0.18 and 0.19, respectively).