. 2012 Jun;78(12):4271–4280. doi: 10.1128/AEM.00309-12

Table 3.

Effects of different doses of essential oils on abundance of rumen archaea, cellulolytic bacteria, and protozoa quantified by real-time PCR^a

Essential oil and dose (g/liter)	Abundance (log₁₀ no. of copies of rrs gene/ml)
Essential oil and dose (g/liter)	Archaea	Total bacteria	F. succinogenes	R. flavefaciens	R. albus	Protozoa
Control, 0	7.31	11.46	7.41	7.62	6.09	8.27
CLO
0.25	6.82	11.41	5.95	7.41	6.14	8.45
0.50	7.08	11.39	4.37	5.81	4.79	7.77
1.00	6.41	10.94	4.14	4.80	4.29	6.03
SEM	0.094	0.080	0.283	0.158	0.079	0.053
Contrast	L,^* C^*	L^***	L,^* Q^*	L,^* C^	L,^* C^*	L,^* Q,^* C^***
EUO
0.25	7.22	11.41	7.05	7.65	6.19	8.42
0.50	7.28	11.63	6.20	7.61	6.01	8.08
1.00	6.84	11.66	4.47	7.08	5.72	7.63
SEM	0.059	0.067	0.110	0.070	0.085	0.124
Contrast	L,^* Q^	NS	L,^* Q^	L,^* Q^	L^***	L^***
GAO
0.25	6.67	11.52	6.50	6.88	5.91	8.25
0.50	6.25	11.24	6.10	6.85	6.04	8.56
1.00	6.10	11.24	5.37	5.91	5.21	7.62
SEM	0.079	0.116	0.055	0.080	0.124	0.114
Contrast	L,^* Q^	NS	L,^* Q,^* C^**	L,^* C^*	L,^*** Q^*	L,^* Q^*
ORO
0.25	6.18	11.18	4.95	5.91	5.29	7.34
0.50	5.81	10.67	3.92	5.10	4.23	5.60
1.00	4.50	9.78	3.59	5.03	4.02	5.36
SEM	0.046	0.126	0.221	0.134	0.207	0.173
Contrast	L,^* Q,^* C^***	L^***	L,^* Q^*	L,^* Q^*	L,^* Q^	L,^* Q,^* C^**
PEO
0.25	6.21	11.51	6.02	6.83	5.86	8.13
0.50	5.83	11.03	4.13	5.46	4.69	7.30
1.00	5.78	10.96	3.63	5.32	4.51	5.53
SEM	0.061	0.085	0.078	0.068	0.110	0.097
Contrast	L,^* Q,^* C^***	L,^* C^	L,^* Q,^* C^***	L,^* Q,^* C^***	L,^* Q,^* C^***	L,^* Q,^* C^*

Data were analyzed using dose levels of 0, 0.25, 0.50, and 1.0 g/liter for each essential oil. CLO, clove oil; EUO, eucalyptus oil; GAO, garlic oil; ORO, origanum oil; PEO, peppermint oil; NS, not significant. Only significant (***, P ≤ 0.01; **, P ≤ 0.05; *, P ≤ 0.10) linear (L), quadratic (Q), and cubic (C) effects are shown.