In vitro rumen fermentation characteristics of substrate mixtures with soybean meal partially replaced by microbially fermented yellow wine lees

Figures & data

Table 1. Chemical composition of substrate mixtures after replacing soybean meal (SBM^a) with unfermented (UM) or fermented yellow wine lees mix (FM) at various ratios (Dry matter basis).

Items	UM	FM	SBM to UM ratio					SBM to FM ratio
			1:0	1:1	1:2	1:5	0:1	1:0	1:1	1:2	1:5	0:1
Dry matter, %	89.1	88.3	88.5	88.6	88.7	88.8	88.9	88.5	88.5	88.4	88.4	88.4
Contents^b, % of DM
OM	94.9	94.3	92.2	92.3	92.4	92.5	92.5	92.2	92.3	92.3	92.5	92.5
CP	26.3	30.2	18.2	15.9	15.2	14.4	13.7	18.2	16.3	15.6	15.0	14.4
EE	2.4	2.8	2.4	2.5	2.5	2.5	2.6	2.4	2.5	2.5	2.5	2.6
NDF	36.4	41.1	42.0	44.0	44.7	45.4	46.1	42.0	44.5	45.4	46.4	47.1
ADF	14.6	16.8	21.2	22.2	22.5	22.9	23.2	21.6	22.4	22.7	22.9	23.2
NFC	29.8	20.2	29.6	29.9	30.0	30.1	30.1	29.6	29.0	28.8	28.6	28.4

^a Soybean meal accounted for 18% of the substrate mixtures.

^b OM: organic matter; CP: crude protein; EE: ether extracts; NDF: neutral detergent fibre; ADF: acid detergent fibre; NFC: nonfibrous carbohydrate.

Table 2. In vitro gas production profiles after replacing soybean meal (SBM^a) with unfermented (UM) or fermented yellow wine lees mix (FM) at various ratios.

Items^b	SBM to UM ratio					SBM to FM ratio						p Value^c
	1:0	1:1	1:2	1:5	0:1	1:0	1:1	1:2	1:5	0:1	SEM	S	R		S × R
													L	Q
Gas value, mL	173	181	185	181	180	173	187	185	183	182	6.120	.5200	.0900	.0100	.3200
a, mL	–2.7000	–6.6000	3.1000	8.1000	19.0000	–2.7000	–1.7000	–0.5800	10.6000	14.3000	0.9600	.6000	<.0100	<.0100	.2300
b, mL	186	195	185	201	180	186	190	199	177	190	6.0200	.7400	.5800	.0600	.0100
a+b, mL	184	188	189	209	199	184	188	199	188	205	5.5300	.6500	<.0100	.7500	.1500
c, %/h	0.0570	0.0640	0.0600	0.0530	0.0420	0.0570	0.0630	0.0600	0.00530	0.0440	0.0008	.0570	<.0100	<.0100	.5800

^a Soybean meal accounted for 18% of the substrate mixtures.

^b Gas production (GP) profiles were estimated by the equation GP=a+ b(1 – exp^–ct), where a or b is the GP (mL) from the rapid or slow degradation fraction, a+ b is the potential GP (mL), c is the GP rate constant (% h⁻¹) and GP is the cumulative gas (mL) at time t (h).

^c S: substrate effect; R: replacement ratio effect; L: linear effect; Q: quadratic effect; S × R: interaction of substrate and replacement ratio.

Table 3. In vitro rumen fermentation parameters after replacing soybean meal (SBM^a) with unfermented (UM) or fermented yellow wine lees mix (FM) at various ratios.

Items^b	SBM to UM ratio					SBM to FM ratio					SEM	p Value^c
	1:0	1:1	1:2	1:5	0:1	1:0	1:1	1:2	1:5	0:1		S	R		S × R
													L	Q
pH	6.64	6.62	6.68	6.64	6.60	6.64	6.64	6.62	6.75	6.70	0.03	.32	.25	.02	.02
NH3-N, mg/dL	15.50	14.50	14.20	13.50	12.90	15.50	14.60	14.50	13.70	13.30	0.28	.28	<.01	.41	.65
MCP, mg/dL	3.52	3.24	3.04	2.88	2.82	3.52	3.49	3.32	3.18	3.16	0.08	<.01	<.01	<.01	.62
Total VFA, mM	83.70	82.10	75.10	74.20	72.20	83.70	82.40	75.70	75.00	73.10	0.470	.40	<.01	<.01	.58
Molar proportion, mM/100 mM
Acetate (Ac)	59.50	59.90	58.70	59.00	60.70	59.50	59.40	59.40	59.80	59.80	0.43	.70	.08	.11	.27
Propionate (Pr)	26.20	26.50	26.90	27.00	26.20	26.20	26.80	26.50	26.10	26.90	0.19	.32	.70	<.01	.01
Butyrate	9.70	9.60	10.00	9.70	9.10	9.70	9.50	9.80	9.80	9.30	0.43	.75	.01	.01	.63
Isoacids	4.70	4.20	4.50	4.30	4.10	4.70	4.40	4.30	4.40	4.00	0.23	.34	.06	.77	.56
Ac:Pr	2.27	2.26	2.22	2.19	2.29	2.27	2.22	2.24	2.27	2.22	0.03	.70	.09	<.01	<.01

^a Soybean meal accounted for 18% of the substrate mixtures.

^b NH₃-N: ammonia nitrogen; MCP: microbial protein; VFAs: volatile fatty acids

^c S: substrate effect; R: replacement ratio effect; L: linear effect; Q: quadratic effect; S × R: interaction of substrate and replacement ratio.

Table 4. In vitro rumen digestibility after replacing soybean meal (SBM^a) with unfermented (UM) and fermented yellow wine lees mix (FM) at various ratios.

Items^b	SBM to UM ratio					SBM to FM ratio						p Value^c
	1:0	1:1	1:2	1:5	0:1	1:0	1:1	1:2	1:5	0:1	SEM	S	R		S × R
													L	Q
IVDMD, %	63.80	63.50	62.80	63.10	62.40	63.80	63.40	62.30	62.30	61.70	0.320	0.28	<0.01	0.33	0.38
IVOMD, %	62.60	62.40	61.80	62.00	61.40	62.80	62.30	61.30	61.80	61.00	0.280	0.24	<0.01	0.57	0.47
IVCPD, %	51.60	51.80	52.10	51.20	51.60	51.60	53.80	54.50	53.30	54.20	0.450	<0.01	<0.01	<0.01	0.56
ENU, %	67.30	68.10	66.20	64.30	64.70	67.30	68.80	67.40	65.70	64.90	0.710	0.01	0.09	0.02	0.45

^a Soybean meal accounted for 18% of the substrate mixtures.

^b DMD: in vitro dry matter digestibility; IVOMD: in vitro organic matter digestibility; IVCPD: in vitro CP digestibility; ENU: efficiency of nitrogen utilisation; ENU: (dietary N + artificial saliva N– undegradable N)/(dietary N + artificial saliva N)

^c S: substrate effect; R: replacement ratio effect; L: linear effect; Q: quadratic effect; S × R: interaction of substrate and replacement ratio.

Table 5. Associative effects of unfermented (UM) or fermented yellow wine lees mix (FM) and soybean meal (SBM^a) on in vitro rumen fermentation variables.

AE, %	SBM to UM ratio			SBM to FM ratio
	1:1	1:2	1:5	1:1	1:2	1:5
Gas production (GP)
Gas value	2.6	4.1^#	1.2	5.4*	3.4	1.4
Potential GP	–1.8	–2.6	6.4*	–3.3	0.5	–6.7*
Rate of GP	29.2**	28.1**	18.6**	24.2**	24.0**	14.6**
Fermentation variables^b
MCP	2.2^#	–0.4	–1.9	4.5**	1.2	–8.7*
Total VFA	7.9**	2.1	4.5^#	5.1**	–1.2	0.2
ENU	3.2^#	1.0	–1.3	4.1**	2.6	0.6
In vitro digestibility^c
IVDMD	0.6	–0.1	0.8	1.0	–0.2	0.4
IVOMD	0.7	–0.0	0.8	0.7	–0.5	0.8
IVCPD	0.4	1.0	–0. 8	1.7^#	2.2	–0.9

^a Soybean meal accounted for 18% of the substrate mixtures.

^b MCP: microbial protein; VFAs: volatile fatty acids; ENU: efficiency of nitrogen utilisation, ENU=(dietary N + artificial saliva N-undegradable N)/(dietary N + artificial saliva N).

^c IVDMD: in vitro dry matter digestibility; IVOMD: in vitro organic matter digestibility; IVCPD: in vitro CP digestibility.

# .05≤p≤.10.

* .01≤p<.05.

** p<.01.