Effects of phytase with orwithout carbohydrases on utilization of nutrients other than P are not well understood in diets adequate in P. Thus, we investigated the effects of Phyzyme XP® (PX) and carbohydrase enzymes (Porzyme®: xylanase and β-glucanase; C) on coefficients of ileal nutrient digestibility (CAID) in growing pigs fed wheat/barley-based diets. The dietswere: 1) basal (B, 8% less DE than NRC, 1998, with no enzymes), 2) B+PX, 3) B+PX+50 g C/MT (B+PX+50C) and 4) B+ PX+100 g C/MT (B+PX+100C). The PX was added at 100 g/MT to all phytase containing feed, and C was added at 50 and 100 g/MT to diets 3 and 4, respectively. Acid insoluble ash was used as an indigestible marker. Diets were fed to 4 barrows (BW 35.9 kg) fitted with a Tcannula at the distal ileum, according to a 4×4 Latin square design. Experimental periods lasted 7 d and ileal digesta were collected in 12-h periods on d-6 and d-7. At the end of the 4- wk period, pigs were fed a 5% casein diet to estimate basal endogenous AA losses. Data were subjected to pre-planned contrasts. Overall, diets containing PX had higher CAID of energy (0.60 vs. 0.58), AA (0.72 vs. 0.69) and phytate (0.56 vs. 0.33) comparedwith the B diet. When corrected for basal endogenous losses, PX-containing diets had higher coefficients of standardized ileal digestibility (CSID) of Met and Thr than the B diet. In the presence of PX, the highest response to C for CAID of energy (0.59 vs. 0.62) was achieved at 50 g/MT; the AID of DM and energy increased by 7.2 and 7.0%, respectively, with 50 g/MT of C compared to B diet. In conclusion, phytase and carbohydrase combined increased CAID of energy, and that PX-containing diets not only increased CAID of AA but resulted in lower diet-specific endogenous losses in a practical diet.

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