Novel mixtures of Italian ryegrass and winter cereals: influence of ensiling on nutritional composition, fermentation characteristics, microbial counts and ruminal degradability

Figures & data

Table 1. Total precipitation (mm) by month during the growing season of 2017–2018.

2017–2018	Precipitation (mm)
September	167 mm
October	64 mm
November	51 mm
December	38 mm
January	17 mm
February	85 mm
March	55 mm
April	5 mm

Table 2. Nutritional composition of silage on 7, 14 and 90 opening days, at different crop mixtures and their interaction (n = 5).

	Components, % DM
	DM, %	CP	EE	CF	NDF	ADF	Sugar	NFE
Day 7
Mixture A	28.300^b	15.480^b	4.320^A	27.860^A	49.300^b,A	32.240	0.320	38.320
Mixture B	30.980^a	15.840^a	4.060^A,B	28.460	51.600^a	32.080^B	0.360	39.440
SEM	0.805	0.217	0.245	0.577	0.502	0.761	0.278	0.801
Day 14
Mixture A	27.360^b	14.980^b	3.820^B	27.820^A	49.800^b,A	31.740	0.120	39.10
Mixture B	31.300^a	15.500^a	3.820^B	28.620	51.800^a	32.740^A,B	0.160	39.140
SEM	0.833	0.340	0.130	0.593	1.024	0.781	0.223	0.865
Day 90
Mixture A	27.460^b	15.240	4.000^b,B	27.060^b,B	48.100^b,B	32.040^b	0.120	38.120
Mixture B	31.340^a	16.080	4.200^a,A	28.600^a	50.360^a	33.720^a,A	0.040	37.980
SEM	0.773	0.636	0.100	0.619	0.899	0.527	0.141	0.904
p value
Day 7	<–0.001	<–0.050	ns	ns	<–0.001	ns	ns	ns
Day 14	<–0.001	<–0.050	ns	ns	<–0.050	ns	ns	ns
Day 90	<–0.001	ns	<–0.050	<–0.010	<–0.010	<–0.010	ns	ns
SEM
Mixture A	0.593	0.330	0.127	0.478	0.570	0.679	0.196	0.736
Mixture B	0.970	0.519	0.204	0.695	1.040	0.742	0.244	0.964
p value
Mixture A	ns	ns	<–0.001	<–0.050	<0.010	ns	ns	ns
Mixture B	ns	ns	<0.050	ns	ns	<0.050	ns	ns
Interaction (day * mixture)
SEM	0.804	0.435	0.170	0.596	0.838	0.711	0.221	0.858
p value	<–0.001	<–0.010	<–0.001	<–0.010	<–0.001	<–0.010	ns	ns

Mixture A: 40% of three cultivars of Italian ryegrass + 20% of two cultivars of winter triticale + 20% of two cultivars of winter oats + 15% of winter wheat + 5% of winter barley; mixture B: 55% of three cultivars Italian ryegrass + 45% of two cultivars of winter oats.

^a,bMeans within a column with different superscripts different (p < .05) caused by opening days effect.

^A,BMeans within a column with different superscripts different (p < .05) caused by mixture effect.

ns: not significant.

DM: dry matter; CP: crude protein; EE: ether extract; CF: crude fibre, NDF: neutral detergent fibre; ADF – acid detergent fibre; NFE – nitrogen free extract; SEM – standard error of the mean.

Tukey test was used.

Table 3. Fermentation characteristics of silage on 7, 14 and 90 opening days, at different crop mixtures and their interaction (n = 5).

	Components
	pH	Ethanol, % DM	Acetate, % DM	Lactate, % DM	LA/AA	LA, % TFA	NH3-N, g/100 g total N
Day 7
Mixture A	4.360^b,A	0.300	2.060	5.590^B	2.880^B	74.200^B	4.700^B
Mixture B	4.470^a,A	0.110	1.810	5.180^B	2.680^B	72.750^B	4.200^B
SEM	0.023	0.202	0.288	0.587	0.206	1.406	0.004
Day 14
Mixture A	4.320^b,B	0.200^a	2.100	6.180 ^B	2.950^B	74.600^B	3.800^b,B
Mixture B	4.430^a,B	0.120^b	1.970	5.340^B	2.830^B	73.470^B	4.600^a,B
SEM	0.022	0.018	0.427	0.596	0.401	2.872	0.005
Day 90
Mixture A	4.260^b,C	0.160^a	2.250^a	8.920^a,A	3.970^A	79.840^A	8.800^A
Mixture B	4.390^a,C	0.110^b	1.910^b	7.030^b,A	3.670^A	78.590^A	8.100^A
SEM	0.020	0.015	0.289	0.877	0.213	0.971	0.011
p value
Day 7	<–0.001	ns	ns	ns	ns	ns	ns
Day 14	<–0.001	<–0.001	ns	ns	ns	ns	<–0.050
Day 90	<–0.001	<–0.010	<–0.050	<–0.010	ns	ns	ns
SEM
Mixture A	0.026	0.165	0.202	0.688	0.203	1.243	0.008
Mixture B	0.015	0.016	0.412	0.711	0.352	2.429	0.005
p value
Mixture A	<–0.001	ns	ns	<–0.001	<–0.001	<–0.001	<–0.001
Mixture B	<–0.001	ns	ns	<–0.010	<–0.010	<–0.010	<–0.001
Interaction (day * mixture)
SEM	0.021	0.117	0.324	0.699	1.929	0.288	0.007
p value	<–0.001	ns	ns	<–0.001	<–0.001	<–0.001	<–0.001

Mixture A: 40% of three cultivars of Italian ryegrass + 20% of two cultivars of winter triticale + 20% of two cultivars of winter oats + 15% of winter wheat + 5% of winter barley; mixture B: 55% of three cultivars Italian ryegrass + 45% of two cultivars of winter oats.

^a,bMeans within a column with different superscripts different (p < .05) caused by opening days effect.

^A,BMeans within a column with different superscripts different (p < .05) caused by mixture effect.

ns: not significant; Tukey test was used.

DM: dry matter; AA: acetic acid; LA: lactic acid; TFA: total fermentation acid; SEM: standard error of the mean.

Table 4. Microorganism count (Log₁₀ CFU g⁻¹) of silage on 7, 14 and 90 opening days, at different crop mixtures and their interaction (n = 5).

	Components
	Aerobic mesophilic microorganism count (AMC), Log10 CFU g^-1(1)	Mould and yeast, Log10 CFU g^-1(1)
Day 7
Mixture A	6.050^B	2.410^a
Mixture B	5.780^A,B	2.030^b
SEM	0.517	0.187
Day 14
Mixture A	5.330^B	2.560
Mixture B	5.530^B	2.400
SEM	0.405	0.749
Day 90
Mixture A	7.230^A	2.880
Mixture B	6.520^A	1.400
SEM	0.511	1.161
p value
Day 7	ns	<–0.050
Day 14	ns	ns
Day 90	ns	ns
SEM
Mixture A	0.424	0.962
Mixture B	0.531	0.607
p value
Mixture A	<–0.001	ns
Mixture B	<–0.050	ns
Interaction (day * mixture)
SEM	0.481	0.804
p value	<–0.001	ns

Mixture A: 40% of three cultivars of Italian ryegrass + 20% of two cultivars of winter triticale + 20% of two cultivars of winter oats + 15% of winter wheat + 5% of winter barley; mixture B: 55% of three cultivars Italian ryegrass + 45% of two cultivars of winter oats.

^a,bMeans within a column with different superscripts different (p < .05) caused by opening days effect.

^A,BMeans within a column with different superscripts different (p < .05) caused by mixture silage effect.

ns: not significant.

⁽¹⁾Counting at silo opening; SEM: standard error of the mean; CFU: colony forming unit.

Tukey test was used.

Table 5. Degradable characteristics of silage (n = 60).

	Mixture A	Mixture B
	(mean)	(mean)	SEM	p value
Dry matter (DM)
Soluble fraction, % of DM	32.040	34.140	3.671	ns
Potentially degradable fraction, % of DM	39.410	39.160	7.205	ns
Degradation rate, % h^–1	0.100	0.050	0.085	ns
Effective degradability-1, %^(1)	64.410	65.580	5.911	ns
Effective degradability-5, %^(1)	52.370	52.300	0.742	ns
Effective degradability-8, %^(1)	48.470	48.230	1.255	ns
Crude protein (CP)
Soluble fraction, % of DM	28.650^b	50.330^a	1.779	<–0.001
Potentially degradable fraction, % of DM	43.590^a	32.390^b	1.191	<–0.001
Degradation rate, % h^–1	0.620^a	0.090^b	0.041	<–0.001
Effective degradability-1, %^(1)	71.550^b	79.200^a	1.697	<–0.01
Effective degradability-5, %^(1)	68.990^b	70.750^a	0.523	<–0.05
Effective degradability-8, %^(1)	67.260	67.190	0.703	ns
Neutral detergent fibre (NDF)
Soluble fraction, % of DM	5.170^a	4.090^b	0.408	<0.050
Potentially degradable fraction, % of DM	80.230	94.350	30.269	ns
Degradation rate, % h^–1	0.017	0.014	0.006	ns
Effective degradability-1, %^(1)	54.110	54.450	10.620	ns
Effective degradability-5, %^(1)	24.750	22.200	2.049	ns
Effective degradability-8, %^(1)	18.680	16.370	1.202	ns
Acid detergent fibre (ADF)
Soluble fraction, % of DM	6.340^a	3.870^b	1.082	<–0.05
Potentially degradable fraction, % of DM	85.180	87.260	32.530	ns
Degradation rate, % h^–1	0.017	0.014	0.007	ns
Effective degradability-1, %^(1)	54.960	53.350	10.932	ns
Effective degradability-5, %^(1)	25.280	22.310	2.007	ns
Effective degradability-8, %^(1)	19.450^a	16.440^b	1.208	<–0.050

Mixture A: 40% of three cultivars of Italian ryegrass + 20% of two cultivars of winter triticale + 20% of two cultivars of winter oats + 15% of winter wheat + 5% of winter barley; mixture B: 55% of three cultivars Italian ryegrass + 45% of two cultivars of winter oats.

^a,bMeans within a row with different superscripts different (min. p < .05).

ns: not significant; SEM: standard error of mean.

⁽¹⁾Effective degradability-1, -5 and -8 are calculated for various rumen solid outflow rates (0.01, 0.05 and 0.08 h⁻¹); Tukey test was used.