. 2023 Mar 23;13:4806. doi: 10.1038/s41598-023-31964-3

Table 6.

Effect of Cut (1–5 where 1, 3 and 5 is the first, second and third cut in the three-cut system, and 2 and 4 is the first and second cut in the two-cut system) and crop (T, Timothy; T + RC, Timothy + red clover; RG, perennial ryegrass) on ensiled herbage in vitro rumen fermentation characteristics (total volatile fatty acids (VFA) and acids as molar proportion of total VFA), in vitro total gas CH₄ production, and fractional rate of gas production (n = 4).

	Cut	Three cuts			Two cuts			SEM	P value¹
	Cut	T	T + RC	RG	T	T + RC	RG	SEM	Cut	Crop	Cut × crop	C1	C2	C3	C4	C5
Total VFA, mmol/L	1st	146	145	145	135	131	132	2.4	< 0.001	0.346	0.030	< 0.001	< 0.001	0.219	0.421	0.500
	2nd	139	140	135	138	134	133
	3rd	132	144	138
Molar Proportions
Acetate, mmol/mmol	1st	0.621	0.628	0.600	0.634	0.636	0.619	0.003	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	0.001	< 0.001	0.007
	2nd	0.625	0.628	0.614	0.630	0.636	0.635
	3rd	0.617	0.625	0.606
Propionate, mmol/mmol	1st	0.200	0.201	0.221	0.205	0.207	0.216	0.003	< 0.001	< 0.001	0.009	0.547	0.534	0.979	< 0.001	0.986
	2nd	0.202	0.199	0.215	0.205	0.204	0.206
	3rd	0.207	0.209	0.223
Butyrate, mmol/mmol	1st	0.100	0.100	0.111	0.098	0.095	0.100	0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	< 0.001	0.015	< 0.001
	2nd	0.104	0.104	0.103	0.099	0.097	0.094
	3rd	0.107	0.100	0.108
Acetate:Propionate	1st	3.10	3.13	2.72	3.12	3.09	2.88	0.053	< 0.001	< 0.001	0.016	0.034	0.469	0.238	< 0.001	0.445
	2nd	3.10	3.16	2.87	3.10	3.14	3.09
	3rd	2.99	3.01	2.73
CH_4, mL/ g DM	1st	32.2	31.4	35.8	28.2	27.5	30.7	0.79	< 0.001	0.005	0.003	< 0.001	< 0.001	0.353	0.003	0.815
	2nd	30.1	31.2	30.2	29.8	30.4	29.1
	3rd	30.3	30.7	31.6
CH₄, mL/g OM	1st	34.6	33.7	38.7	30.0	29.1	32.9	0.86	< 0.001	< 0.001	0.002	< 0.001	< 0.001	0.299	< 0.001	0.460
	2nd	32.4	33.8	32.5	31.7	32.7	31.7
	3rd	32.6	33.7	34.7
CH₄, mL/g DOM	1st	46.0	44.4	50.1	45.4	44.0	49.7	1.17	0.004	< 0.001	0.017	0.309	0.711	0.309	< 0.001	0.827
	2nd	43.9	45.0	48.0	46.5	46.7	45.9
	3rd	43.2	44.2	44.5
Total gas, mL/g DM	1st	194	196	204	178	176	186	4.1	< 0.001	0.226	0.264	< 0.001	< 0.001	0.268	0.183	0.732
	2nd	183	176	180	175	178	174
	3rd	190	190	190
Total gas, mL/g OM	1st	208	210	221	189	186	200	4.4	< 0.001	0.032	0.219	< 0.001	< 0.001	0.217	0.014	0.751
	2nd	197	191	194	186	192	190
	3rd	204	209	209
Total gas, mL/g DOM	1st	277	277	285	285	281	301	5.9	< 0.001	0.002	0.007	0.047	0.087	0.462	0.008	0.365
	2nd	268	254	286	272	274	274
	3rd	270	274	267
CH₄, ml/L of total gas	1st	165	159	177	162	157	166	4.8	0.019	0.261	0.082	0.924	0.270	0.920	0.129	0.855
	2nd	164	178	168	172	171	168
	3rd	160	160	165
Fractional rate of gas production, /h	1st	0.058	0.061	0.064	0.058	0.055	0.060	0.0012	< 0.001	0.065	< 0.001	< 0.001	0.012	0.003	0.035	0.058
	2nd	0.058	0.061	0.059	0.056	0.056	0.055
	3rd	0.060	0.064	0.061

C1 is the contrast three versus two cuts per season, overall; C2 is the contrast three versus two cuts per season, 1st cut; C3 is the contrast three versus two cuts per season, 2nd cut; C4 is the contrast T versus RG; C5 is contrast T versus T + RC. DM, dry matter; OM, organic matter, DOM, digestible organic matter.