An observational study to verify the influence of different nutritional corn silage-based strategies on efficient use of dietary nutrients, faecal fermentation profile, and profitability in a cohort of intensive dairy farms

Figures & data

Figure 1. Dendrogram of cluster analysis.

Table 1. Diet ingredient formulation in different nutritional strategy clusters.

Ingredients, as % of DM	Cluster 1	Cluster 2	Cluster 3	Cluster 4	Cluster 5	Cluster 6	√MSE	p of the model
Corn silage	16.3^c	30.0^ab	33.1^a	31.2^ab	26.7^b	33.1^a	6.28	<.05
High moisture corn	10.0^b	0.0^c	0.0^c	17.6^a	0.0^c	18.3^a	4.33	<.05
Alfalfa silage	14.9^a	0.8^b	1.4^b	1.2^b	1.0^b	2.8^b	3.50	<.05
Grass Silage	6.8	8.2	12.2	6.1	7.9	5.7	6.64	.086
Alfalfa hay	1.4	6.1	2.9	2.5	0.6	3.8	4.31	.348
Grass Hay	6.4	1.8	7.0	6.6	9.1	4.6	5.57	.304
Straw	1.4	0.0	0.2	0.8	0.7	0.6	1.18	.331
By products feeds	1.0	0.0	0.0	0.8	0.6	0.0	1.32	.323
High Value Protein Rich Feed	1.3^b	0.0^b	10.6^a	11.0^a	0.8^b	1.4^b	3.38	<.05
Low Value Protein Rich Feed	0.0	0.0	0.3	0.9	0.0	0.0	1.56	.551
TRT Protein Rich Feed	0.0^a	0.0^a	0.2^ab	1.3^b	0.0^a	0.0^a	1.36	.040
Corn meals	0.0^c	7.8^b	21.0^a	8.0^b	20.7^a	4.7^bc	4.67	<.05
White starch meals	0.0	0.0	0.7	0.1	1.1	0.0	1.43	.434
TRT starch feeds	2.6^a	0.0^bc	0.0^c	0.0^c	1.9^ab	0.0^bc	1.78	<.05
Full fat seeds	0.0	0.0	1.7	1.1	0.0	0.0	1.90	.095
Fat feeds	0.0	0.0	0.2	0.3	0.2	0.1	0.43	.652
Molasses	0.0	0.0	0.5	1.7	1.6	0.5	1.81	.158
Cotton seeds	0.0	0.0	0.3	1.6	1.5	0.0	2.16	.211
Mineral-Vitamins and Additives^1	0.0^c	0.0^c	1.4^ab	1.8^a	1.3^abc	0.7^bc	1.25	<.05
Starch Compound Feed^2	25.9^b	45.4^a	0.8^c	1.1^c	0.5^c	0.1^c	4.96	<.05
Protein Compound Feed^2	12.0^b	0.0^c	2.2^c	0.8^c	23.9^a	23.7^a	4.24	<.05
Restricted Compound Feed^2	0.0	0.0	3.5	3.0	0.0	0.0	4.56	.161

¹When possible, information about the exact compound feeds formula was obtained, otherwise the classification in these categories was based on the label.

The mean values with different superscript letters in a row are significantly different (p < .05).

Table 2. Diet composition calculated by using analysed feed composition and the output parameters obtained from the NRC (2001) animal nutrition model or gas production parameters in different nutritional strategy clusters.

Items^1	u.m.	Cluster 1	Cluster 2	Cluster 3	Cluster 4	Cluster 5	Cluster 6	√MSE	p Of the model
Dry matter intake	Kg DM/d per cow	24.2	22.4	22.7	23.7	23.5	22.9	2.05	.507
Total Digestible Nutrients	% DM	64.3	64.0	65.5	65.3	65.2	65.0	1.01	.511
Digestible Energy	Mcal/kg DM	2.88	2.89	2.91	2.92	2.92	2.92	0.04	.419
Metabolisable Energy	Mcal/kg DM	2.26	2.27	2.30	2.31	2.30	2.30	0.04	.268
Net Energy for Lactation (3×)	Mcal/kg DM	1.55	1.56	1.58	1.59	1.59	1.58	0.03	.145
Crude Protein	% DM	16.1	16.0	16.5	16.6	17.1	16.4	1.11	.489
Ether extract	% DM	4.2	3.9	3.7	4.2	4.4	3.7	0.68	.127
Rumen Undegradable CP	% DM	5.5	5.5	6.0	5.9	6.1	5.5	0.66	.245
Soluble CP	% DM	4.5	4.5	4.8	4.7	4.6	5.0	0.45	.337
Starch	% DM	25.9	25.5	27.5	28.1	26.9	27.3	3.91	.800
Sugar	% DM	3.8	3.9	4.0	4.1	4.4	3.4	1.02	.447
NDF	% DM	31.2	30.5	31.1	28.5	29.9	30.8	2.69	.058
ADF	% DM	20.2^a	19.8^ab	20.1^a	18.0^b	18.9^ab	19.2^ab	1.94	<.05
ADL	% DM	3.7	3.5	3.0	3.1	3.1	3.2	0.68	.518
Neutral detergent insoluble CP	% DM	3.4^a	3.2^a	2.7^b	2.7^b	3.7^a	3.4^a	0.44	<.05
Acid detergent insoluble CP	% DM	1.4^a	1.4^ab	1.2^b	1.2^b	1.5^a	1.4^a	0.17	<.05
Lysine	% DM	0.67	0.66	0.66	0.68	0.66	0.66	0.07	.959
Methionine	% DM	0.23	0.23	0.24	0.23	0.26	0.24	0.03	.056
Gas production parameters
Final volume	ml/g OM	188.1^bc	176.2^c	217.2^a	201.6^b	209.3^ab	192.4^bc	19.3	<.05
Rate of gas production	1/h	0.051^a	0.046^ab	0.042^b	0.052^a	0.046^ab	0.053^a	0.0074	<.05
Lag time	h	1.47	1.91	2.20	1.59	1.60	1.56	1.02	.453

¹Abbreviations: CP: Crude Protein; NDF: Neutral Detergent Fibre; ADF: Acid Detergent Fiber; ADL: Acid Detergent Lignin.

The mean values with different superscript letters in a row are significantly different (p < .05).

Table 3. Herd characteristics, milk yield and composition in different nutritional strategy clusters.

Items	u.m.	Cluster 1	Cluster 2	Cluster 3	Cluster 4	Cluster 5	Cluster 6	√MSE	p Of the model
Primiparous	n°	42	35	63	83	43	62	40.1	.080
Pluriparous	n°	73	51	105	133	78	87	66.3	.102
Dry cows	n°	13	11	24	30	12	19	19.2	.130
Heifers	n°	110	77	158	211	122	144	105.8	.104
Primiparous on lactating cows	%	36.9	41.3	38.2	37.8	36.3	42.4	6.2	.281
Pluriparous on lactating cows	%	63.1	59.7	61.8	62.2	63.7	57.6	6.4	.342
Days in milk	n°	195^a	241^b	186^a	170^a	181^a	178^a	22.4	<.05
Number of lactation	n°	2.28	2.77	2.45	2.31	2.29	2.12	0.33	.091
Milk yield	Kg/cow/day	33. 0	27.8	29.5	33.0	31.0	34.3	4.80	.061
4% fat corrected milk	Kg/cow/day	34.3	28.8	31.0	34.3	32.1	31.9	3.97	.059
Energy corrected milk	Kg/cow/day	36.4	30.8	32.8	36.4	34.2	34.2	4.19	.060
Fat	%	4.06	4.11	4.11	4.09	4.03	4.00	0.275	.907
Protein	%	3.45	3.60	3.51	3.49	3.51	3.51	0.100	.424
Casein	%	2.64	2.78	2.72	2.73	2.77	2.75	0.088	.300
Lactose	%	4.95^c	4.97^c	5.00^bc	5.04^a	5.04^a	5.03^ab	0.0433	<.05
Somatic cell count	cell/mL	230000	192000	189529	183976	212778	175600	63194	.633
Total bacterial count	UFC/mL	9000	10250	8765	10548	18278	6287	9069	.108
Urea	mg/dL	23.67	22.43	22.19	22.08	22.46	22.76	3.20	.958

The mean values with different superscript letters in a row are significantly different (p < .05).

Table 4. Estimated diet digestibility and economic indexes in different nutritional strategy clusters.

Items^1	u.m.	Cluster 1	Cluster 2	Cluster 3	Cluster 4	Cluster 5	Cluster 6	√MSE	p Of the model
Real Dry matter intake	Kg DM/d per cow	23.2	21.6	21.8	22.9	23.1	22.2	1.73	.248
Feed efficiency	dmnl	1.60^ab	1.44^b	1.52^b	1.61^a	1.50^b	1.54^ab	0.114	<.05
Metabolisable energy efficiency	dmnl	0.45	0.36	0.39	0.42	0.40	0.41	0.046	.053
Net energy efficiency	dmnl	0.71	0.56	0.62	0.66	0.63	0.65	0.076	.063
Residual energy intake	Mcal/day	2.59	5.21	3.75	5.29	4.98	3.71	4.229	.758
Crude protein digestibility	% CP	85.6^a	72.8^c	78.8^b	84.2^a	80.7^ab	82.6^ab	5.37	<.05
NDF digestibility	% NDF	70.6	65.6	67.0	69.5	65.9	65.3	8.24	.693
Starch digestibility	% Starch	98.8^a	96.7^c	97.6^bc	98.6^a	98.0^ab	98.8^a	0.96	<.05
Income over feed costs	€/cow/day	6.65	4.90	6.48	7.21	5.93	6.51	1.514	.083
Income equal feed costs	litre/cow/day	17.2	16.3	14.5	15.3	16.5	14.7	1.94	.053
Feed Costs for hundredweight of milk	€/kg of milk	0.21^bc	0.24^a	0.19^c	0.19^c	0.22^ab	0.19^c	0.021	<.05

¹Abbreviations: NDF: Neutral Detergent Fibre; dmnl: dimensionless.

Table 5. Faecal fermentation profile for different nutritional strategy clusters.

Items^1	u.m.	Cluster 1	Cluster 2	Cluster 3	Cluster 4	Cluster 5	Cluster 6	√MSE	p Of the model
Acetic acid	mmol/kg DM	264.2	341.3	341.8	321.2	371.7	273.8	75.51	.060
Propionic acid	mmol/kg DM	47.7^b	65.3^ab	64.3^ab	61.4^ab	66.2^a	51.1^b	12.77	<.05
Isobutyric acid	mmol/kg DM	2.7	3.3	3.3	3.2	3.4	2.9	0.81	.663
Butyric acid	mmol/kg DM	20.9^cd	38.4^ab	37.2^ab	28.9^bc	44.4^a	18.9^d	10.99	<.05
Isovaleric acid	mmol/kg DM	2.1	2.6	2.7	2.6	2.6	2.0	0.78	.282
Valeric acid	mmol/kg DM	3.0^b	3.7^ab	3.7^b	3.6^b	4.7^a	2.9^b	0.94	<.05
Total VFA	mmol/kg DM	340.7^b	454.6^ab	453.1^ab	421.2^ab	493.2^a	351.4^b	93.115	<.05
Acetic acid	% total VFA	76.9	74.9	75.4	76.1	75.2	77.8	2.75	.295
Propionic acid	% total VFA	14.6	14.4	14.3	14.6	13.5	14.6	1.28	.392
Isobutyric acid	% total VFA	1.0	0.7	0.8	0.8	0.7	0.9	0.24	.323
Butyric acid	% total VFA	5.7^cd	8.5^ab	8.1^ab	6.9^bc	9.0^a	5.2^d	1.96	<.05
Isovaleric acid	% total VFA	0.8	0.6	0.6	0.6	0.5	0.6	0.22	.545
Valeric acid	% total VFA	0.9	0.8	0.8	0.9	0.9	0.9	0.22	.668

¹Abbreviations: VFA: Volatile Fatty acid.

The mean values with different superscript letters in a row are significantly different (p < .05).

Figure 2. Loading scores or specific parameters of interest on first two extracted principal components.

NRC 2001. Nutrient requirements of dairy cattle. 7th rev ed. Washington (DC): National Academy of Sciences.

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Data availability statement

The data that support the findings of this study are available from the corresponding author, AG, upon reasonable request.