Table 5. Effects of crude protein level and supplementation protease level on digestibility of nutrients in weaned piglets and growing-finishing pigs

Item Main effects SE p-value
Protein level Protease level CP Protease CP × protease
HP LP PT0 PT1 PT2
Week 4
 DM 78.58 78.58 78.98 78.64 78.12 0.26 0.992 0.453 0.734
 CP 72.42 74.21 73.53 73.76 72.66 0.36 0.013 0.362 0.794
Week 12
 DM 80.66 81.24 81.17 81.01 80.66 0.17 0.095 0.440 0.661
 CP 75.95 77.45 76.51 76.88 76.71 0.29 0.014 0.858 0.938
Week 20
 DM 82.63 82.77 82.63 83.00 82.48 0.16 0.664 0.432 0.736
 CP 79.15 80.69 79.79 80.41 79.56 0.37 0.035 0.575 0.295
Each value is the mean value of 4 replicates (4 pigs/pen).
HP, high crude protein (19.00% [days 1–14 phase], 18.05% [days 15–28 phase], 17.10% [growing phase] and 16.15% [finishing phase]); LP, low crude protein (17.00% [days 1–14], 16.15% [days 15–28], 15.30% [growing phase] and 14.45% [finishing phase]); PT0, protease 0 ppm (weanling-finishing phase); PT1, protease 300 ppm (weanling phase) and 150 ppm (growing-finishing phase); PT2, protease 500 ppm (weanling phase) and 300 ppm (growing-finishing phase) ; CP, crude protein; DM, dry matter.