Table 5. Effects of different protease and nutrient density feed on gas emission in growing-finishing pigs

Items (ppm)	High¹⁾			Basal			SE	Den		Pro			p-value
Items (ppm)	CON	PTA	PTB	CON	PTA	PTB	SE	High	Basal	CON	PTA	PTB	Den	Pro	Den× Pro
H₂S
6 wk	4.73	4.38	4.53	4.55	4.53	4.48	0.131	4.54	4.52	4.64	4.45	4.50	0.819	0.358	0.475
13 wk	5.30	4.80	5.00	5.40	4.60	5.10	0.146	5.04	5.03	5.35^a	4.73^b	5.03^b	0.890	0.002	0.554
NH₃
6 wk	3.45	3.18	3.35	3.53	3.13	3.30	0.126	3.33	3.32	3.49^a	3.15^b	3.33^ab	0.936	0.049	0.850
13 wk	3.40	3.10	3.30	3.60	3.20	3.20	0.129	3.28	3.34	3.52^a	3.16^b	3.26^ab	0.587	0.039	0.476

High nutrient density is 0.94%–0.98% higher than requirement in dietary protein and 50 kcal/kg in energy than basal nutrient density.
Means in the same row with difference superscripts differ at p < 0.05.
High, high nutrient density diet; Basal, basal nutrient density diet; Den, different nutrient density diet; Pro, supplementation of protease; CON, basal diet; PTA, CON + 0.0125% protease A; PTB, CON + 0.010% protease B; Den × Pro, different nutrient density diet × supplementation of protease; H₂S, hydrogen sulfide; NH₃, ammonia.