Woyengo, T. A., Akinremi, O. O., Rossnagel, B. G. and Nyachoti, C. M. 2012. Performance and total tract nutrient digestibility of growing pigs fed hulless low phytate barley. Can. J. Anim. Sci. 92: 505–511. An experiment was conducted to determine the performance and nutrient digestibility of growing pigs fed hulless low phytate (HLP) barley without or with phytase for 28 d. Twenty-four growing pigs (average initial body weight=25.3 kg) were fed three diets in a completely randomised design. The diets included a regular-hulled barley-based diet, and a HLP barley-based diet without or with phytase at 500 phytase units kg−1. Pigs fed the HLP barley-based diet without phytase had greater (P<0.05) average daily gain (0.911 vs. 0.717 kg), and apparent total tract digestibility of dry matter, energy, P, Mg, and Na were higher (P<0.05) than the regular barley-based diet. Supplementation of phytase to the HLP barley-based diet resulted in improved (P<0.05) feed conversion efficiency (0.506 vs. 0.547 kg kg−1), and apparent total tract digestibility of N, P and K. In conclusion, pigs fed the HLP barley-based diet had higher growth performance and nutrient digestibility than those fed the regular-hulled barley-based diet, indicating that the HLP barley is a better source of nutrients for pigs than regular barley. Phytase supplementation to the HLP barley-based diet can result in a further increase in nutrient utilisation by pigs.