Table 3. Fermentation characteristics and CH₄ production after 24 h in vitro incubation of the experimental diets using strained ruminal fluid.

	Treatmentsa						P-value
Item	Control	SCG	FSCG	APR	FAPR	SEMb	Overall	Control vs. SCG	Control vs. APR	SCG vs. APR	Fermen-tationc
pH	6.58d	6.59d	6.58d	6.55e	6.55e	0.000	<0.01	0.07	<0.01	<0.01	0.63
NH3–N, mg/100 ml	11.9	12.1	11.5	11.7	11.5	0.24	0.39	0.79	0.27	0.30	0.20
NDF digestibility, g/kg DM	293.5de	252.4e	242.3e	259.8e	316.9d	11.43	<0.01	<0.01	0.72	<0.01	0.07
Gas production, ml/g DM	193.7	184.6	180.7	192.2	184.4	3.20	0.07	<0.05	0.20	0.11	0.10
Gas production, ml/KRW	532.7de	553.5d	516.9de	551.8d	501.9e	9.03	<0.01	0.83	0.61	0.38	<0.01
CH4, ml/g DM	19.2	18.1	18.0	18.8	20.3	0.78	0.27	0.24	0.71	0.07	0.39
VFA profiles
Total VFA, mmol/g DM	5.99	5.87	5.82	5.97	6.06	0.090	0.41	0.24	0.80	0.09	0.80
Total VFA, mmol/KRW	16.43	17.60	16.67	17.13	16.50	0.267	0.05	0.06	0.27	0.26	<0.05
Acetate, mmol/mol	602.0	601.0	598.9	599.7	599.5	1.64	0.67	0.32	0.25	0.84	0.51
Propionate, mmol/mol	201.2	199.4	198.4	201.0	200.9	1.37	0.55	0.20	0.88	0.16	0.70
Butyrate, mmol/mol	166.6e	168.8de	172.1d	168.8de	169.1de	0.80	0.01	<0.01	<0.05	0.08	<0.05
A/P ratio	2.99	3.02	3.02	2.98	2.98	0.028	0.81	0.43	0.89	0.26	0.91

Notes.

^aSCG; spent coffee grounds, FSCG; fermented spent coffee grounds, APR; Artemisia princeps residues, FAPR; fermented Artemisia princeps residues. The SCG, FSCG, APR and FAPR treatments contained 100 g/kg of SCG, FSCG, APR, and FAPR, respectively.

^bSEM; standard error of the mean.

^cStatistical difference between fermented and non-fermented substrates (SCG, APR vs. FSCG, FAPR).

^d,e Means that do not have common superscript differ significantly (P < 0.05).