Effect of row spacing and maturity at harvest on the fermentative profile, aerobic stability, and nutritional characteristics of biomass sorghum (BRS 716) silage in the semiarid region of Brazil

Fausto Expedito de Queiroz

Universidade Estadual de Montes Claros, Departamento de Ciências Agrárias, Janaúba, MG, Brasil.

Vicente Ribeiro Rocha Júnior^**Corresponding author:vicente.rocha@unimontes.br

Universidade Estadual de Montes Claros, Departamento de Ciências Agrárias, Janaúba, MG, Brasil.

Flávio Pinto Monção

Universidade Estadual de Montes Claros, Departamento de Ciências Agrárias, Janaúba, MG, Brasil.

João Paulo Sampaio Rigueira

Universidade Estadual de Montes Claros, Departamento de Ciências Agrárias, Janaúba, MG, Brasil.

Rafael Augusto da Costa Parrella

Embrapa Milho e Sorgo, Sete Lagoas, MG, Brasil.

Leidy Darmony de Almeida Rufino

Epamig Norte, Nova Porteirinha, MG, Brasil.

Alexandre Soares dos Santos

Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, MG, Brasil.

Matheus Wilson Silva Cordeiro

Universidade Estadual de Montes Claros, Departamento de Ciências Agrárias, Janaúba, MG, Brasil.

Author Contributions

Conceptualization: V.R. Rocha Júnior, F.P. Monção and M.W.S. Cordeiro. Data curation: V.R. Rocha Júnior and F.P. Monção. Formal analysis: F.E. Queiroz, V.R. Rocha Júnior, F.P. Monção, A.S. Santos and M.W.S. Cordeiro. Funding acquisition: R.A.C. Parrella. Methodology: F.E. Queiroz, V.R. Rocha Júnior, F.P. Monção, A.S. Santos and M.W.S. Cordeiro. Project administration: V.R. Rocha Júnior and F.P. Monção. Resources: R.A.C. Parrella. Supervision: V.R. Rocha Júnior, F.P. Monção and J.P.S. Rigueira. Validation: V.R. Rocha Júnior. Writing-original draft: F.E. Queiroz, V.R. Rocha Júnior, F.P. Monção, J.P.S. Rigueira, R.A.C. Parrella, L.D.A. Rufino, A.S. Santos and M.W.S. Cordeiro. Writing-review & editing: F.E. Queiroz, V.R. Rocha Júnior, F.P. Monção, J.P.S. Rigueira, R.A.C. Parrella, L.D.A. Rufino, A.S. Santos and M.W.S. Cordeiro.

Item	Spacing (cm)	Maturity at harvest (days)				SEM	P-value

		70	100	130	160		IdL	IdQ	Spa	Id × Spa
pH¹	45	3.45	3.15	2.55	3.30	0.06	<0.01	<0.01	0.59	0.18
	70	3.50	3.13	2.33	3.38
	90	3.40	3.23	2.30	3.33
N-NH₃ (%TN)²	45	11.34	3.20	3.24	4.26	0.42	<0.01	<0.01	0.15	0.13
	70	11.11	3.10	3.72	3.30
	90	11.85	2.41	4.58	4.78
Gas losses (% DM)³	45	18.69	14.47	8.00	6.93	2.53	<0.01	0.18	0.58	0.79
	70	13.45	10.96	9.44	8.17
	90	15.92	10.63	6.67	7.87
Losses effluents (kg fresh mass/t)⁴	45	40.47	41.25	36.18	37.46	2.56	<0.01	0.29	0.52	0.54
	70	47.97	44.50	34.22	36.62
	90	42.72	44.83	33.41	36.42
DM recovery (%)⁵	45	76.04	78.62	80.43	95.23	2.53	<0.01	<0.01	0.39	0.54
	70	76.30	78.91	87.80	97.20
	90	80.23	78.31	83.99	93.63
Aerobic stability (h)⁶	45	168 A	138 A	126 A	126 A	11.22	0.01	<0.01	0.05	<0.01
	70	168 A	96 B	102 A	120 A
	90	108 B	120 AB	114 A	150 A

Item (% DM)	Spacing (cm)	Maturity at harvest (days)				Mean	SEM	P-value

		70	100	130	160			IdL	IdQ	Spa	Id × Spa
Malic acid¹	45	21.20	6.27	4.95	7.38	9.95 AB	1.88	<0.01	<0.01	0.03	0.06
	70	19.26	7.73	8.05	7.47	10.62 A
	90	10.97	4.57	4.02	9.00	7.14 B
Succinic acid²	45	0.78	0.26	0.34	0.37	0.44 B	0.03	<0.01	<0.01	<0.01	0.07
	70	1.03	0.34	0.54	0.56	0.90 A
	90	0.85	0.28	0.28	0.46	0.46 B
Lactic acid³	45	1.34	1.55	1.46	1.36		0.09	0.06	0.01	0.66	0.47
	70	1.38	1.59	1.48	1.15
	90	1.34	1.67	1.25	1.18
Acetic acid⁴	45	0.36	0.25	0.53	0.70		0.05	<0.01	<0.01	0.88	0.44
	70	0.36	0.25	0.53	0.70
	90	0.51	0.23	0.48	0.69
Butyric acid	45	<0.01	UN	UN	UN		<0.01	0.16	0.28	0.68	0.96
	70	<0.01	UN	UN	UN
	90	0.01	UN	UN	UN
Ethanol⁵	45	0.65	0.45	0.73	1.68	0.87 B	0.05	<0.01	<0.01	<0.01	0.07
	70	0.68	0.52	0.87	1.83	0.97 A
	90	0.54	0.36	0.52	1.79	0.80 B

Item (% DM)	Spacing (cm)	Maturity at harvest (days)				SEM	P-value

		70	100	130	160		IdL	IdQ	Spa	Id × Spa
Dry matter¹	45	16.56	19.18	22.59	27.03	0.79	<0.01	0.01	0.19	0.83
	70	16.91	19.72	22.14	26.91
	90	16.04	18.42	20.38	27.06
Ash²	45	9.71	7.53	8.26	4.73	0.34	<0.01	0.04	0.32	0.44
	70	9.34	7.48	7.57	4.68
	90	10.08	6.89	7.70	4.18
Crude protein³	45	10.00	8.45	5.69	5.51	0.33	<0.01	<0.01	0.24	0.06
	70	10.17	7.04	6.06	5.33
	90	9.77	7.95	6.12	6.19
Ether extract⁴	45	3.71	1.53	2.18	2.64	0.34	<0.01	<0.01	0.11	0.27
	70	4.48	1.89	1.50	2.97
	90	4.41	2.13	3.08	3.07
Total carbohydrates⁵	45	76.58	82.49	83.87	87.55	0.57	<0.01	<0.01	0.14	0.44
	70	76.02	83.59	84.86	87.63
	90	75.75	83.02	83.10	87.31
Non-fibrous carbohydrates⁶	45	15.95	16.12	18.88	20.04	1.25	<0.01	<0.01	0.11	0.10
	70	13.99	19.67	23.60	21.22
	90	14.11	19.85	19.35	20.11
NDFap⁷	45	60.62	66.37	64.99	67.51	1.32	<0.01	0.91	0.24	0.45
	70	62.02	63.93	61.26	66.41
	90	61.64	63.17	63.75	65.85
Acid detergent fiber⁸	45	40.90	47.05	46.94	46.71	1.67	<0.01	0.01	0.10	0.92
	70	37.35	44.44	43.44	46.00
	90	40.58	44.73	46.27	45.97
Lignin⁹	45	7.28	10.62	11.08	12.38	1.24	0.01	0.05	0.23	0.69
	70	7.01	9.65	8.55	9.98
	90	8.10	8.79	9.81	11.17
iNDF¹⁰	45	7.54	15.45	16.93	18.40	1.16	<0.01	<0.01	0.22	0.71
	70	9.56	14.10	16.42	18.21
	90	10.82	16.50	16.64	19.41
Total digestible nutrients¹¹	45	50.08	45.51	46.66	47.92	0.95	0.13	<0.01	0.12	0.93
	70	51.28	47.03	47.83	49.05
	90	50.66	47.72	48.74	49.73

Item (% DM)	Spacing (cm)	Maturity at harvest (days)				SEM	P-value

		70	100	130	160		IdL	IdQ	Spa	Id × Spa
Fraction A¹	45	16.81	18.54	15.95	13.85	1.18	<0.01	0.11	0.27	0.30
	70	18.76	17.80	18.45	15.63
	90	20.56	16.92	15.83	14.91
Fraction B	45	47.97	50.12	48.32	53.32	3.14	0.07	0.32	0.42	0.13
	70	54.45	54.36	43.85	50.53
	90	53.85	48.95	46.90	42.00
Degradation rate of fraction B “c” (%/h)²	45	3.00	2.00	1.00	1.00	<0.10	<0.01	0.05	0.44	0.07
	70	2.00	1.00	1.00	1.00
	90	2.00	1.00	2.00	2.00
Colonization time (h)³	45	3.93	6.70	8.69	7.50	1.43	<0.01	0.34	0.31	0.32
	70	5.37	6.26	9.54	11.24
	90	6.23	7.63	6.54	6.79
Potential degradability⁴	45	64.78	68.66	64.27	67.17	1.77	<0.01	0.44	0.28	0.08
	70	73.21	72.16	62.30	66.16
	90	74.41	65.86	62.73	56.91
Effective degradability (k = 5%/h)⁵	45	34.33	30.27	24.54	22.54	1.28	<0.01	0.09	0.80	0.12
	70	32.93	29.89	28.07	23.14
	90	35.31	26.70	26.71	24.53

Item (% DM)	Spacing (cm)	Maturity at harvest (days)				Mean	SEM	P-value

		70	100	130	160			IdL	IdQ	Spa	Id × Spa
Fraction Bp¹	45	67.61	61.99	54.16	61.93	61.42 A	2.00	<0.01	<0.01	<0.01	0.08
	70	68.47	67.47	54.99	62.20	63.28 A
	90	68.23	51.90	50.03	43.45	53.39 B
Degradation rate of fraction B “c” (%/h)	45	2.00	1.75	1.50	1.25		0.01	0.06	0.95	0.21	0.86
	70	1.50	1.50	1.50	1.25
	90	1.75	1.00	1.25	1.00
Colonization time (h)²	45	5.30	5.60	5.00	7.58		1.10	<0.01	0.02	0.14	0.07
	70	8.10	6.21	6.38	9.32
	90	4.96	4.17	8.40	16.91
Effective degradability (k = 5%/h)³	45	31.98	27.59	20.05	24.85		1.72	<0.01	<0.01	0.13	0.42
	70	30.25	27.02	25.47	24.46
	90	30.41	17.07	20.04	23.41
Indigestible fraction⁴	45	32.39	38.00	45.83	38.07	38.57 B	1.73	<0.01	<0.01	<0.01	0.08
	70	31.53	32.53	45.00	37.80	36.71 B
	90	31.76	48.10	49.97	56.55	46.60 A

Brasil