Table 1 Effect of the tannin-essential oil mixtures Q-2 and C-10 compared to negative control (NC) and positive control (PC) on ruminal fermentation variables

pH

7.02^b

7.11^a

7.08^a

7.00^b

0.028

 < 0.001

NH₃-N, mmol/L

10.52^a

6.94^c

6.67^c

7.84^b

0.927

 < 0.001

Volatile fatty acids, mmol/L

82.4^a

68.2^b

70.7^b

81.4^a

1.35

 < 0.001

Branched-chain volatile fatty acids, mmol/L

5.23^a

5.21^ab

4.91^b

5.29^a

0.255

0.006

Proportions of volatile fatty acids, % of total

 Acetate

49.16^a

49.52^a

48.09^b

49.39^a

1.030

 < 0.001

 Propionate

22.69^a

17.24^d

19.64^c

21.42^b

2.303

 < 0.001

 iso-butyrate

1.33^b

1.60^a

1.54^a

1.32^b

0.178

 < 0.001

 Butyrate

15.61^c

19.30^a

19.44^a

16.86^b

2.600

 < 0.001

 iso-valerate

5.06^c

6.07^a

5.40^b

5.19^bc

0.200

 < 0.001

 Valerate

6.15^ab

6.26^a

5.88^bc

5.82^c

1.033

 < 0.001

Acetate:propionate ratio

2.22^c

2.96^a

2.49^b

2.36^b

0.220

 < 0.001

Ruminal degradabilites

 Dry matter (dDM), %

59.5^a

55.2^b

57.8^a

58.7^a

0.84

 < 0.001

 Organic matter (dOM), % of supply

59.2^a

51.6^c

55.4^b

56.7^b

0.91

 < 0.001

 Organic matter (dOM_DM), % of dry matter (DM) supply

45.7^a

42.6^b

43.8^b

44.4^ab

0.72

 < 0.001

 Neutral detergent fibre (dNDF), % of supply

36.2^a

31.2^b

25.5^c

28.2^bc

1.67

 < 0.001

 Neutral detergent fibre (dNDF_DM), % of DM supply

17.6^a

15.5^b

11.6^c

12.9^c

0.80

 < 0.001

 Crude protein (dCP), % of supply

84.9^a

82.5^b

82.9^b

83.6^b

0.42

 < 0.001

Protozoa, 10³/mL

131^a

4^b

118^a

155^a

25.9

 < 0.001

Bacteria, 10⁹/mL

1.11^b

1.40^ab

1.51^a

1.23^ab

0.160

 < 0.01