Effects of Two Sources of Tannins (Quercus L. and Vaccinium Vitis Idaea L.) on Rumen Microbial Fermentation: an in Vitro Study

Figures & data

Table 1. Chemical composition of the feeds (n=3) used in the in vitro studies.

	Diet, g/kg DM	DM, g/kg	OM, g/kg DM	aNDF, g/kg DM
Corn silage	206	449	424	202
Lucerne silage	165	260	231	118
Meadow hay, chopped	225	924	888	603
Wheat grain, ground	142	894	887	142
Corn grain, ground	103	896	881	211
Rapeseed meal	158	920	856	184
Mineral components	1	980	-	-

DM, dry matter; OM, organic matter; aNDF, neutral detergent fibre.

Table 2. Effects of 2.5 g of tannin supplementation from Quercus cortex, Vaccinium vitis idaea and their combination on the in vitro rumen microbial population and rumen fermentation parameters.

	Control	QC	VVI	QC+VVI	SEM
pH	6.95	6.86	6.90	6.90	0.018
Ammonia, mmol/L	12.6^a	10.3^b	9.72^b	9.84^b	0.254
Methane, mM	3.11^a	2.55^b	2.43^b	2.53^b	0.059
Gas production, 10^3 mL TGP	2.95^b	3.67^a	3.70^a	3.31^ab	0.127
Methane/TGP, x10^–3/mL	1.10^a	0.72^b	0.70^b	0.80^b	0.040
Protozoa, x10^3/mL	9.54^a	6.29^b	6.40^b	6.47^b	0.350
Bacteria, x10^3/mL	28.8	35.7	47.1	38.3	3.33
Methanogens, x10/mL	58.4^a	44.1^b	30.1^c	39.2^b	1.37
Apparent digestibility
DM	0.525	0.511	0.520	0.535	0.770
OM	0.525	0.511	0.521	0.536	0.796
aNDF	0.219	0.181	0.205	0.242	1.17

QC, Quercus cortex; VVI, Vaccinium vitis idaea; TGP, total gas production; DM, dry matter; OM, organic matter; aNDF, neutral detergent fibre.

^a,bDifferent superscripts indicate differences between means in the same row (P<0.05).

Table 3. In vitro volatile fatty acid production by mixed rumen microbes as an effect of Quercus cortex, Vaccinium vitis idaea and their combined supplementations.

	Control	QC	VVI	QC+VVI	SEM
Total VFA	82.2	78.7	81.4	76.8	1.29
A	44.38	41.55	41.59	39.36	0.820
P	11.87^b	12.72^a,b	14.25^a	12.70^a,b	0.278
Isobutyrate	2.34^a,b	1.94^b	2.40^a	1.95^a,b	0.059
Butyrate	13.39^a	11.97^a	10.94^a,b	9.76^b	0.373
Isovalerate	4.77^b	5.34^b	6.97^a,b	8.11^a	0.404
Valerate	5.48	5.17	5.27	4.90	0.188
A/P	3.78^a	3.30^a,b	2.98^b	3.11^b	0.099

QC, Quercus cortex; VVI, Vaccinium vitis idaea; VFA, volatile fatty acids; A, acetate; P, propionate.

^a,bDifferent superscripts indicate differences between means in the same row (P<0.05).