Ruminal degradation and fermentation kinetics of the Mulato II grass (Convert HD364) under different sources of nitrogen fertilization

Jacovetti, Reginaldo; França, Aldi Fernandes de Souza; Basto, Debora de Carvalho; Brunes, Ludmilla Costa; Oliveira, Leonardo Guimarães; Ribeiro, Renata Vaz; Silva, Mirella Paula Costa e; Arnhold, Emmanuel; Ferreira, Reginaldo Nassar

doi:10.1590/1809-6891v24e-75660E

Acessibilidade / Reportar erro

Brasil

Ciência Animal Brasileira

Español English

Brasil

Español English

sumário « anterior atual seguinte »

Sumário

Animal science / Research article • Ciênc. anim. bras. 24 • 2023 • https://doi.org/10.1590/1809-6891v24e-75660E copy

Ruminal degradation and fermentation kinetics of the Mulato II grass (Convert HD364) under different sources of nitrogen fertilization

Authorship SCIMAGO INSTITUTIONS RANKINGS

Abstract

It is important to evaluate nutritional value of new grass species, which can be better characterized through rumen fermentation and degradation techniques. The aim was to evaluate the effects of Nitrogen (N) fertilization on the kinetics of fermentation and ruminal degradation of the Mulato II grass. Two distinct sources of N (common and protected urea) were used during two periods of the year (summer - I and autumn - II). A completely randomized experimental design was used, in a 2x4 factorial arrangement with three replicates. Fraction A changed based on N dosage. The passage rate (K) and effective degradability (ED) were influenced by sources and doses of N, while Fraction B and Lag Time were not influenced during period I. Fractions A and B and EDs were all influenced by N sources and doses during period II. Lag time and potential degradability were influenced by N sources only. Among the kinetics parameters of dry matter ruminal fermentation obtained during period I, only K1 was influenced by the interaction between N doses x sources, while the remaining parameters were only influenced by the N doses applied. As for period II, with the exception of K2, all remaining parameters were influenced by the interaction of N doses and sources. Protected urea improved fermentation parameters during period I. The dose equivalent to applying 150kg/ha positively influenced ruminal fermentation parameters of the Mulato II grass mainly in the summer. The use of protected urea as a Nitrogen source improved fermentation parameters in the summer.

Keywords:
Brachiaria; digestibility; digestion kinetics; rumen fermentation; gas production

pH	S	P^* * P-Mehlich 1.	P^ P-Resin. CEC: cation exchange capacity; Base sat.: base saturation; Al sat.: aluminum saturation	K	K	Ca	Mg	H + Al	Al	CEC
CaCl₂	(mg/dm³)				(cmol/100 dm³)
5.0	13	2	5	120	0.31	1.7	0.7	2.2	0.0	5.0
Clay	Silt	Sand	Base sat.		Al sat.	OM	Ca/CEC	Mg/CEC	K/CEC
%
45	19	36	56		0	2.7	34	14	6

Parameter		Nitrogen dose
		Control	50		100		150
		Control	Com	Prot	Com	Prot	Com	Prot
Summer	NDF (%)	55.35	50.93	53.6	57.96	54.93	49.58	50.39
	ADF (%)	28.03	26.96	27.06	30.18	28.29	28.42	25.67
	Lignin (%)	6.95	6.21	5.74	5.79	6.04	7.35	5.56
Fall	NDF (%)	57.67	58.85	57.09	60.03	58.12	56.66	55.46
	ADF (%)	29.69	31.43	30.65	30.05	30.02	28.76	29.00
	Lignin (%)	7.85	8.05	7.93	9.57	7.88	7.78	8.68

Summer
Parameter	Source of urea	Control	Nitrogen dose (kg/ha)			MSE	CV (%)
Parameter	Source of urea	Control	50	100	150	MSE	CV (%)
Fraction A	Common	35.63^{b^* * indicates that values with the same lowercase letter in the same row and uppercase in the column do not differ from each other (p > 0.05).}	38.18^a	37.25^ab	38.04^ab	0.63	3.38
Fraction A	Protected	35.63^b	38.79^a	38.22^a	38.78^a	0.63	3.38
Fraction B	Common	49.67^a	46.73^a	48.11^a	48.88^a	0.95	3.92
Fraction B	Protected	49.67^a	47.16^a	46.91^a	49.42^a	0.95	3.92
K (%/h)	Common	3.00^b	4.60^Aa	1.90^c	4.00^a	0.003	16.74
K (%/h)	Protected	3.00^a	2.50^Ba	2.50^a	3.50^a	0.003	16.74
ED (k = 2%)	Common	65.22^b	70.27^Aa	60.78^Bc	70.63^a	0.54	1.62
ED (k = 2%)	Protected	65.22^b	64.88 ^Bb	64.25^Ab	70.15^a	0.54	1.62
ED (k = 5%)	Common	54.05^b	60.18^Aa	50.58^Bc	59.78^a	0.54	1.94
ED (k = 5%)	Protected	54.05^b	54.44^Bb	53.85^Ab	59.05^a	0.54	1.94
Lag time	Common	1.45^a	1.45^a	0.84^a	0.55^a	0.35	66.34
Lag time	Protected	1.45^a	0.47^a	1.10^a	1.20^a	0.35	66.34
DP	Common	85.30^a	84.91^a	85.36^a	86.92^a	0.71	1.65
DP	Protected	85.30^b	85.95^b	85.13^b	88.20^a	0.71	1.65
Fall
Parameter	Source of urea	Control	Nitrogen dose (kg/ha)			MSE	CV (%)
Parameter	Source of urea	Control	50	100	150	MSE	CV (%)
Fraction A	Common	37.22^a	36.24^ab	33.93^Bb	34.42^Bb	0.70	3.88
Fraction A	Protected	37.22^a	37.00^a	36.77^Aa	36.63^Aa	0.70	3.88
Fraction B	Common	48.11^ab	46.97^b	48.94^ab	50.19^Aa	0.54	2.24
Fraction B	Protected	48.11^a	48.33^a	48.33^a	46.52^Ba	0.54	2.24
K (%/h)	Common	2.60^b	2.90^ab	3.20^ab	3.50^a	0.002	11.56
K (%/h)	Protected	2.60^a	2.70^a	3.10^a	3.20^a	0.002	11.56
ED (k = 2%)	Common	64.49^ab	63.96^b	63.90^Bb	66.18^a	0.52	1.59
ED (k = 2%)	Protected	64.49^a	64.71^a	66.12^Aa	64.92^a	0.52	1.59
ED (k = 5%)	Common	53.78^a	53.41^a	52.89^Ba	54.91^a	0.53	1.95
ED (k = 5%)	Protected	53.78^a	53.90^a	55.28^Aa	54.53^a	0.53	1.95
Lag time	Common	0.70^a	0.85^a	1.27^a	0.99^Aa	0.19	43.69
Lag time	Protected	0.70^a	1.02^a	0.94^a	0.42^Ba	0.19	43.69
DP	Common	85.33^a	83.22^Ba	82.86^Ba	84.62^a	0.67	1.59
DP	Protected	85.33^a	85.34^Aa	85.09^Aa	83.15^a	0.67	1.59

Summer
Parameter	Source of urea	Control	Nitrogen dose (kg/ha)
Parameter	Source of urea	Control	50	100	150
VF1 (mL/g DM)	Common	7.86^{a^* * indicates that values with the same lowercase letter in the same row and uppercase in the column do not significantly differ from each other (p > 0.05) by the Model Identity test.}	7.66^a	8.29^a	7.97^a
VF1 (mL/g DM)	Protected	7.86^b	8.96^a	7.80^b	7.89^b
K1 (%/h)	Common	3.90^a	4.40^a	4.00^Aa	3.90^Ba
K1 (%/h)	Protected	3.90^b	4.10^b	2.90^Bc	4.90^Aa
Lag time (h)	Common	9.51^a	7.57^b	7.65^b	7.58^Ab
Lag time (h)	Protected	9.51^a	8.14^b	8.20^b	6.83^Bc
VF2 (mL/g DM)	Common	4.21^a	3.31^a	3.96^a	4.77^a
VF2 (mL/g DM)	Protected	4.21^ab	3.13^b	4.55^a	3.21^b
K2 (%/h)	Common	9.00^a	12.60^a	11.10^a	10.60^a
K2 (%/h)	Protected	9.00^b	14.80^a	9.70^b	17.60^a
Fall
Parameter	Source of urea	Control	Nitrogen dose (kg/ha)
Parameter	Source of urea	Control	50	100	150
VF1 (mL/g DM)	Common	7.70^{b^* * indicates that values with the same lowercase letter in the same row and uppercase in the column do not significantly differ from each other (p > 0.05) by the Model Identity test.}	6.16^b	9.63^a	7.18^Bb
VF1 (mL/g DM)	Protected	7.70^b	7.64^b	8.43^ab	9.50^Aa
K1 (%/h)	Common	3.60^a	3.80^a	4.10^a	3.80^Ba
K1 (%/h)	Protected	3.60^b	4.40^a	4.10^ab	4.70^Aa
Lag time (h)	Common	7.73^b	8.53^a	7.94^b	6.73^Bc
Lag time (h)	Protected	7.73^a	7.60^a	8.29^a	8.08^Aa
VF2 (mL/g DM)	Common	3.85^a	4.63^a	1.83^b	3.63^Aa
VF2 (mL/g DM)	Protected	3.85^a	3.22^a	2.58^ab	1.48^Bb
K2 (%/h)	Common	9.70^a	10.6^a	12.00^a	12.30^a
K2 (%/h)	Protected	9.70^b	12.9^b	14.40^ab	24.10^a

Universidade Federal de Goiás Universidade Federal de Goiás, Escola de Veterinária e Zootecnia, Campus II, Caixa Postal 131, CEP: 74001-970, Tel.: (55 62) 3521-1568, Fax: (55 62) 3521-1566 - Goiânia - GO - Brazil
E-mail: revistacab@gmail.com

Acompanhe os números deste periódico no seu leitor de RSS

[1] *Corresponding author: ludmillabrunes@hotmail.com