In this study, two trials were conducted to determine phosphorus (P) digestibility and metabolizable energy (ME) concentrations of compound feeds. The feeds were formulated with either wheat or hybrid rye supplemented with soybean meal (SBM) or rapeseed meal (RSM). The compound feeds were fed with (+) (trial 1) or without (−) (trial 2) phytase supplementation to estimate the effect of intrinsic phytase activity in wheat and rye. In addition, nitrogen (N) balance of the test rations was evaluated. The P content in each test ration, consisting of a basal ration (deficient in P) and a compound feed, was adjusted to keep digestible P below 2.0 g/kg dry matter. All compound feeds were tested in a duplicate 3 × 3 Latin Square design. Pigs were kept in metabolism crates for a 7-day adaptation period and a 5-day collection period during which faeces and urine were quantitatively collected. Phytase supplementation (P < 0.05) and the source of protein supplementation (P < 0.05) exerted an influence on P digestibility. Phytase supplementation levelled P digestibility, resulting in values of 70.2% and 69.5% for SBM-compound feed and RSM-compound feed, respectively. The type of cereal grain had no effect on P digestibility of compound feeds, indicating that intrinsic phytase did not show differential efficacy. The ME concentration of all compound feeds was high (≥ 14.2 MJ/kg dry matter) and appropriate for growing pigs. Phytase supplementation had no effect on ME concentration of compound feeds. Rye and RSM, containing higher fibre concentration than wheat and SBM, shifted N excretion from urine to faeces, which may help to reduce ammonia release from slurry.