Table 5.

Effects of diet, time collection of sample and their interaction on the relative abundance of ruminal bacteria at genus level (% of the total) in ruminal fluid collected from Holstein calves fed a control diet (CTR) and a nitrate-containing diet (NIT).

Item	Diet		Time1			SEM	P-value
	CTR	NIT	0 h	4 h	8 h		Diet	Time	D × T
Group of diminished bacteria by NIT diet
Succiniclasticum	1.90	0.59	1.19	1.16	1.39	0.069	0.004	0.354	0.132
Coprococcus	1.87	0.44	0.87	1.67	0.92	0.225	0.015	0.167	0.848
Treponema	1.31	0.66	1.10	0.89	0.97	0.315	0.033	0.062	0.585
Shuttlewortia	1.07	0.20	0.68	0.56	0.65	0.117	0.007	0.052	0.591
Succinivibrio	0.84	0.01	0.34	0.57	0.37	0.106	0.006	0.603	0.279
Pseudobutyrivibrio	0.58	0.04	0.41a	0.16b	0.36ab	0.036	0.002	0.016	0.056
Sharpea	0.32	0.04	0.14	0.22	0.18	0.032	0.010	0.642	0.185
Selenomona	0.22	0.10	0.13	0.13	0.21	0.023	0.024	0.270	0.271
Group of increased bacteria by NIT diet
Atopobium	0.18	0.52	0.55a	0.36ab	0.13b	0.052	0.023	0.015	0.008
Erysipelotrichaceae_L7A_E11	0.08	0.21	0.20a	0.10b	0.13b	0.011	0.010	0.005	0.010
Fibrobacter	<0.01	0.08	0.04	0.02	0.06	0.009	0.003	0.240	0.192
Group of bacteria unchanged by NIT diet
Prevotella	17.16	16.68	15.79	17.40	17.58	0.583	0.856	0.409	0.778
Ruminococcus	6.18	7.34	4.71b	9.66a	5.90b	0.530	0.483	0.004	0.511
Butyrivibrio	3.55	4.59	5.08a	3.42b	3.72ab	0.254	0.207	0.037	0.065
Ruminococeae_Clostridium	0.92	0.99	0.96b	0.89b	1.02a	0.110	0.804	0.011	0.823
Oscillospira	0.79	0.80	0.74	0.80	0.84	0.093	0.971	0.920	0.828
Bulleidia	0.65	0.42	0.49	0.77	0.35	0.143	0.886	0.133	0.164
Moryella	0.13	0.19	0.19	0.12	0.18	0.018	0.132	0.277	0.572
Streptococcus	0.07	0.07	0.07	0.08	0.06	0.005	0.642	0.185	0.262
Schwartia	0.07	0.02	0.05	0.03	0.06	0.004	0.065	0.088	0.417
Lactobacilus	0.07	0.02	0.05	0.04	0.04	0.016	0.090	0.535	0.067
Mogibacterium	0.04	0.06	0.07a	0.05ab	0.03b	0.005	0.256	0.020	0.184

D × T = Diet × Time interaction.

^{a, b} Within a row, means with different superscripts differ at P ≤ 0.05.

¹0 h: pre-feeding period; 4 and 8 h: post-feeding periods.