Effect of Soapwort Root on Rumen Fluid Fermentability Characteristics and Gas Production

Treatments	CTRL	SR1	SR2	SR3
g/kg of substrate DM	3.367	29.490	42.550	55.620
mg/mL of rumen fluid	0.056	0.492	0.709	0.930
Saponin concentration in buffered rumen fluid (%)	0.0056	0.049	0.071	0.093

Table 2.

Ingredients and chemical composition of the basal substrate (CTRL) and soapwort root.

	Basal substrate (CTRL)	Soapwort root
Ingredients (g/kg)
alfalfa	250	0
green grass	250	0
corn grain	500	0
soapwort root	0	1000
dry matter (g/kg)	551.50	925.60
Chemical composition (g/kg DM)
ether extract (EE)	28.00	3.40
crude protein (CP)	135.00	95.50
crude ash (CA)	59.20	74.65
neutral detergent fibre (NDF)	521.00	236.00
acid detergent fibre (ADF)	146.75	98.20
crude fibre (CF)	142.85	87.70
non-structural carbohydrate (NSC)	256.80	590.45
nitrogen-free extractives (NFE)	634.95	738.75
acid detergent lignin (ADL)	50.50	64.17
cellulose	96.25	33.92
hemicellulose	372.50	135.48
holocellulose	468.75	169.40
saponins	3.37	55.62

The effect of soapwort root supplementation on *in vitro* gas production kinetics in rumen fluid was assessed using the ANKOM RF Gas Production System over the incubation period. The polynomial regression model (y = Intercept + B1x + B2x2 + B3x3) provided the optimal fit for CTRL and used substrates. CTRL – the basal substrate (25% alfalfa, 25% green grass, 50% corn grain). SR1 – basal substrate supplemented with 29.49 mg/g of saponins; SR2 – basal substrate supplemented with 42.55 mg/g of saponins; SR3 – the powdered root of *Saponaria officinalis* (soapwort)

Table 3.

The impact of soapwort root supplementation on rumen fluid pH, gas production, CH₄ concentration, and hydrogen content in 24 hours of fermentation

Parameters	CTRL	SR1	SR2	SR3	SEM	P-value
pH	6.53 a	6.46	6.47	6.45 b	0.012	0.013
GNM (mmol/L)	87.62 A	84.93	69.23 Bb	81.05 a	87.62	0.016
CH₄ (mmol/L)	15.76 A	7.20	7.57 B	5.09 B	1.035	0.001
H₂ (%)	91.50 Aa	74.20 b	73.07 b	65.95 Bb	2.862	0.013
CH₄/VFA	1.26 A	0.47 Ba	0.46 Ba	0.28 Bb	0.189	0.000

[i] H₂% – hydrogen recovery; VFA – volatile fatty acids; GNM – gas produced in ml/L reduced by CH₄ ml/L; SEM – standard error of the mean; CTRL – the basal substrate (25% alfalfa, 25% green grass, 50% corn grain); SR1 – basal substrate supplemented with 29.49 mg/g of saponins; SR2 – basal substrate supplemented with 42.55 mg/g of saponins; SR3 – the powdered root of Saponaria officinalis (soapwort). Values in the same row with different lowercase letters differ significantly (a, b, c, etc.) at P<0.05 and values in the same rows with different capital letters (A, B, C, etc.) differ significantly at P<0.01.

Table 4.

Volatile fatty acids (VFA) concentrations during in vitro rumen fluid fermentation of different substrates

Parameters	CTRL	SR1	SR2	SR3	SEM	P-value
Total VFA¹	66.03 b	71.96	78.88	81.33 a	2.363	0.012
Individual VFA, mol%
Acetic acid	57.46 a	55.29 b	55.79 b	55.28 b	0.349	0.012
Propionic acid	27.40 B	38.47 A	37.37 A	36.99 A	0.896	0.001
Isobutyric acid	0.72 B	0.36 A	0.32 A	0.39 A	0.042	0.002
Butyric acid	11.83 A	4.68 Bb	5.17 Bb	5.84 Ba	0.494	0.000
Isovaleric acid	0.85 A	0.38 B	0.45 B	0.42 B	0.049	0.001
Valeric acid	1.22 Aa	0.60 b	0.56 B	0.81 B	0.067	0.001
Isocaproic acid	0.14	0.14	0.10	0.07	0.021	0.605
Hexanoic acid	0.28 a	0.06 b	0.18 b	0.18 b	0.030	0.050

1 mmol in the buffered ruminal fluid after fermentation; SEM – standard error of the mean; CTRL – the basal substrate (25% alfalfa, 25% green grass, 50% corn grain); SR1 – basal substrate supplemented with 29.49 mg/g of saponins; SR2 – basal substrate supplemented with 42.55 mg/g of saponins; SR3 – the powdered root of Saponaria officinalis (soapwort). Values in the same row with different lowercase letters differ significantly (a, b, c, etc.) at P<0.05 and values in the same rows with different capital letters (A, B, C, etc.) differ significantly at P<0.01.

Table 5.

The influence of substrates on fermentation parameters

Parameters	CTRL	SR1	SR2	SR3	SEM	P-value
E1 (%)	72.3 Bb	75.37 a	76.62 A	77.43 A	0.511	0.001
E2 (%)	17.66 Aa	14.56 b	13.35 B	12.50 B	0.516	0.001
FE (%)	77.5 B	80.70 A	80.75 A	81.17 A	0.291	0.001
A:P	2.14 A	1.50 B	1.50 B	1.45 B	0.056	0.001
P:B	2.43 A	6.38 Cb	7.29 Ab	8.30 Aa	0.383	0.001
NGR	2.82 A	1.78 B	1.75 B	1.67 B	0.087	0.001
CY¹	3.42 Bb	4.02	4.45 A	4.62 a	0.139	0.011

1 g/L of undiluted ruminal fluid; E1 – the efficiency of fermented hexose energy to VFA energy; E2 – CH₄ energy; FE – fermentation efficiency; NGR – the ratio of nonglucogenic to glucogenic volatile fatty acids; CY – index of cell yield; SEM – standard error of the mean. CTRL – the basal substrate (25% alfalfa, 25% green grass, 50% corn grain). SR1 – basal substrate supplemented with 29.49 mg/g of saponins; SR2 – basal substrate supplemented with 42.55 mg/g of saponins; SR3 – the powdered root of Saponaria officinalis (soapwort). Values in the same row with different lowercase letters differ significantly (a, b, c, etc.) at P<0.05 and values in the same rows with different capital letters (A, B, C, etc.) differ significantly at P<0.01.

Table 6.

Pearson’s correlation coefficients (R) between fermentation characteristics, volatile fatty acid production, and greenhouse gas emissions

Variables	GNM	CH₄	H₂	CH₄/VFA	Total VFA	Acetic acid	Propionic acid	Isobutyric acid	Butyric acid	Isovaleric acid	Valeric acid	Isocaproic acid	Hexanoic acid	A:P
GNM
CH₄	0.039
H₂	−0.060	0.524**
CH₄/VFA	−0.022	0.953**	0.589**
Total VFA	−0.047	0.034	−0.004	−0.222
Acetic acid	−0.058	0.399*	−0.476*	0.393*	−0.235
Propionic acid	−0.130	−0.795**	−0.022	−0.795**	0.273	−0.732**
Isobutyric acid	−0.149	0.850**	0.398*	0.846**	−0.026	0.397*	−0.749**
Butyric acid	0.256	0.780**	0.230	0.778**	−0.249	0.410*	−0.914**	0.702**
Isovaleric acid	0.063	0.871**	0.287	0.811**	0.037	0.471*	−0.797**	0.851**	0.747**
Valeric acid	−0.001	0.810**	0.578**	0.821**	−0.055	0.142	−0.644**	0.797**	0.715**	0.632**
Isocaproic acid	0.208	−0.165	−0.215	−0.104	−0.297	0.086	−0.042	−0.160	0.013	−0.021	−0.259
Hexanoic acid	−0.131	0.355*	0.245	0.489*	−0.440*	0.274	−0.393*	0.257	0.322	0.174	0.325	−0.009
A:P	0.126	0.790**	−0.006	0.781**	−0.247	0.757**	−0.993**	0.734**	0.891**	0.787**	0.616**	0.057	0.378*
P:B	−0.204	−0.762**	−0.217	−0.776**	0.281	−0.445*	0.901**	−0.716**	−0.957**	−0.745**	−0.706**	0.081	−0.358*	−0.859**

[i] GNM – gas produced in ml/L reduced by CH₄ ml/L; VFA – volatile fatty acids; A:P – acetate to propionate ratio; P:B – propionate to butyrate ratio; Asterisks (* and **) indicate a significant correlation at P<0.05 and 0.01.

Table 7.

Pearson’s correlation coefficients (R) between calculated fermentation parameters

Variables	H₂	CH₄/VFA	E1	E2	A:P	P:B	NGR	FE
H₂
CH₄/VFA	0.589*
E1	0.053	−0.464*
E2	−0.067	0.452*	−1.000**
A:P	−0.006	0.781**	−0.592**	0.588**
P:B	−0.217	−0.776**	0.559**	−0.554**	−0.859**
NGR	0.057	0.785**	−0.585**	0.582**	0.988**	−0.907**
FE	0.072	−0.752**	0.628**	−0.625**	−0.989**	0.859**	−0.968**
CY	−0.043	−0.343*	0.960**	−0.960**	−0.385*	0.427*	−0.402*	0.413*

[i] GNM – gas produced in ml/L reduced by CH₄ ml/L; VFA – volatile fatty acids; E1 – the efficiency of fermented hexose energy to VFA energy; E2 – CH₄ energy; FE – fermentation efficiency; A:P – acetate to propionate ratio; and propionate to butyrate ratio;

[ii] NGR – the ratio of nonglucogenic to glucogenic volatile fatty acids; CY – index of cell yield;

[iii] Asterisks (* and **) indicate a significant correlation at P<0.05 and 0.01.

References

Authors

Metrics

Articles in this issue

DOI: https://doi.org/10.2478/aoas-2025-0109 | Journal eISSN: 2300-8733 (formerly 1642-3402) | Journal ISSN: 1642-3402

Journal RSS Feed

Language: English

Page range: 1035 - 1050

Submitted on: Dec 4, 2024

Accepted on: Sep 26, 2025

Published on: Sep 26, 2026

Published by: National Research Institute of Animal Production

In partnership with: Paradigm Publishing Services

Publication frequency: 4 issues per year

Keywords:

Saponaria officinalis,

rumen fermentation,

volatile fatty acids,

methane

Related subjects:

Medicine,

Veterinary medicine

© 2026 Ewa Pecka-Kiełb, Bożena Króliczewska, Alina Pikhtirova, Andrzej Zachwieja, Jowita Kaszuba, Jarosław Króliczewski, published by National Research Institute of Animal Production
This work is licensed under the Creative Commons Attribution 4.0 License.

Volume 26 (2026): Issue 3 (August 2026)

Effect of Soapwort Root on Rumen Fluid Fermentability Characteristics and Gas Production

Figures & Tables

Table 1.

Table 2.

Figure 1.

Table 3.

Table 4.

Table 5.

Table 6.

Table 7.

Paradigm

My account