Table 3.

Effect of sodium nitrate (NaNO₃) on short chain fatty acids (SCFA) after 6, 12, and 24h of incubation with rumen microbes in an in-vitro mixed batch culture system fed varying forege:concentrate (HF = 70:30, MF = 50:50, and LF = 30:70) in experiment 1.

	Diet 1
	HF				MF				LF
	NaNO3, g/kg DM													p <
Item	0	7	14	28	0	7	14	28	0	7	14	28	SE	D2	L3	DxL4
6 Hr
Total SCFA, mM	83.87	88.24	81.71	52.26	84.65	82.95	74.74	61.24	72.08	71.85	61.36	52.66	12.70	0.220	0.020	0.95
Acetate (A), mol%	66.84	68.72	69.29	68.15	64.54	67.00	68.40	70.85	62.09	62.97	68.80	72.33	2.07	0.450	0.003	0.20
Propionate (P), mol%	24.99	23.06	23.87	27.59	25.72	24.55	23.61	22.51	26.59	26.76	22.09	19.69	2.40	0.730	0.370	0.22
Butyrate, mol%	6.99	6.92	5.71	2.71	8.26	6.60	6.14	5.00	9.04	8.19	7.17	5.86	0.96	0.010	0.001	0.64
Valerate, mol%	0.96	0.86	0.75	1.01	1.09	0.96	0.98	0.81	1.31	1.18	1.05	1.14	0.17	0.060	0.430	0.86
Isoacids, mol%	0.22	0.43	0.37	0.38	0.39	0.43	0.40	0.35	0.50	0.42	0.42	0.49	0.37	0.840	0.990	1.00
A:P	2.68	3.02	2.91	2.68	2.54	2.72	2.89	3.14	2.32	2.36	3.10	3.66	0.29	0.970	0.030	0.11
12 Hr
Total SCFA, mM	110.67	112.29	112.01	95.70	100.14	108.54	111.39	89.27	103.60	99.74	112.28	94.53	9.10	0.080	0.001	0.36
Acetate (A), mol%	62.85	64.09	65.32	69.65	61.45	61.80	63.08	68.49	59.04	59.81	58.41	67.44	2.00	0.001	0.001	0.12
Propionate (P), mol%	27.01	25.33	25.47	23.95	26.74	27.55	25.77	24.08	26.47	25.94	26.89	24.64	3.25	0.590	0.010	0.67
Butyrate, mol%	8.69	9.06	7.73	5.29	10.35	9.53	9.81	6.20	12.88	12.82	13.20	6.74	1.42	0.001	0.001	0.03
Valerate, mol%	1.02	1.12	1.04	0.71	1.18	0.94	1.07	0.81	1.21	1.12	1.15	0.77	0.12	0.340	0.001	0.54
Isoacids, mol%	0.42	0.40	0.44	0.40	0.29	0.18	0.27	0.41	0.39	0.31	0.35	0.41	0.14	0.001	0.040	0.29
A:P	2.42	2.59	2.62	2.93	2.35	2.39	2.49	2.86	2.27	2.34	2.21	2.77	0.38	0.003	0.001	0.75
24 Hr
Total SCFA, mM	134.72	147.29	148.06	134.93	138.63	140.94	139.10	128.74	129.56	132.66	140.51	131.89	3.51	0.020	0.002	0.27
Acetate (A), mol%	58.33	59.92	59.24	62.20	55.27	55.95	56.08	58.68	48.54	49.18	49.41	51.49	1.35	0.001	0.030	1.00
Propionate (P), mol%	26.84	25.71	27.32	28.04	27.69	26.37	26.95	28.49	26.93	25.57	26.63	29.11	2.10	0.760	0.003	0.92
Butyrate, mol%	13.34	12.79	11.75	8.39	15.61	16.24	15.48	11.28	22.70	23.21	22.03	17.41	2.47	0.001	0.001	1.00
Valerate, mol%	1.10	1.18	1.13	1.00	1.02	1.03	1.11	1.23	1.28	1.42	1.30	1.39	0.16	0.001	0.520	0.17
Isoacids, mol%	0.39	0.39	0.56	0.37	0.41	0.41	0.38	0.32	0.55	0.62	0.63	0.59	0.12	0.001	0.420	0.72
A:P	2.18	2.34	2.18	2.23	2.00	2.14	2.10	2.07	1.82	2.01	1.87	1.77	0.17	0.001	0.150	0.96

¹HF, high forage; MF, medium forage; LF, low forage.

²Diet effect.

³Treatment level effect.

⁴Diet and level interaction.