Reduction of crude protein in diets fed to lactating Holstein-Gyr cows

The objective of this work was to evaluate the effect of reducing crude protein (CP) contents in diets with a constant metabolizable protein content on the intake, performance, nitrogen balance, and nutrient digestibility of lactating Holstein-Gyr cows. Animals (n = 24, 103±23 days in milk) were allocated to four treatments (n = 6 per group) with different CP contents: 127, 132, 139, and 156 g kg^-1 dry matter (DM). DM intake was not affected by treatments. CP intake and digestibility increased linearly with higher CP contents. Milk yield (23.7±3 kg per day) and the percentages of milk protein (3.3±0.2%) and fat (3.8±0.5%) were not affected by CP reduction. Milk and blood urea nitrogen increased linearly with the increase of CP in the diet, similarly to urinary nitrogen excretion. Nitrogen use efficiency was 29.8 and 22.4% when CP was 127 and 156 g kg^-1 DM, respectively. Reducing CP in diets fed to mid-lactating Holstein-Gyr cows increases nitrogen use efficiency and maintains the productive performance of the cows.

Index terms:
nitrogen; protected soybean meal; Soypass; urea

Authorship

Clóvis Ribeiro Guimarães

Universidade Federal de Minas Gerais, Escola de Veterinária, Departamento de Zootecnia, Campus Pampulha, Avenida Antônio Carlos, no 6.627, Caixa Postal 567, CEP 31270-901 Belo Horizonte, MG, Brazil. E-mail: clovisguimaraes3@hotmail.com, rafaelzooufmg@gmail.com, lrcarvalheira@gmail.com, sandragesteiracoelho@gmail.com Universidade Federal de Minas GeraisBrazilBelo Horizonte, MG, BrazilUniversidade Federal de Minas Gerais, Escola de Veterinária, Departamento de Zootecnia, Campus Pampulha, Avenida Antônio Carlos, no 6.627, Caixa Postal 567, CEP 31270-901 Belo Horizonte, MG, Brazil. E-mail: clovisguimaraes3@hotmail.com, rafaelzooufmg@gmail.com, lrcarvalheira@gmail.com, sandragesteiracoelho@gmail.com

Rafael Alves de Azevedo

Mariana Magalhães Campos

Embrapa Gado de Leite, Rua Eugênio do Nascimento, no 610, Dom Bosco, CEP 36038-330 Juiz de Fora, MG, Brazil. E-mail: mariana.campos@embrapa.br, fernanda.machado@embrapa.br, thierry.tomich@embrapa.br, luiz.gustavo@embrapa.brEmbrapa Gado de LeiteBrazilJuiz de Fora, MG, BrazilEmbrapa Gado de Leite, Rua Eugênio do Nascimento, no 610, Dom Bosco, CEP 36038-330 Juiz de Fora, MG, Brazil. E-mail: mariana.campos@embrapa.br, fernanda.machado@embrapa.br, thierry.tomich@embrapa.br, luiz.gustavo@embrapa.br

Fernanda Samarini Machado

Alexandre Mendonça Pedroso

Cargill Agrícola S.A., Rua Henri Dunant, no 1.383, Diamond Tower, 7º Andar, Chácara Santo Antônio, CEP 04710-230 São Paulo, SP, Brazil. E-mail: alexandre_pedroso@cargill.comCargill Agrícola S.A.BrazilSão Paulo, SP, BrazilCargill Agrícola S.A., Rua Henri Dunant, no 1.383, Diamond Tower, 7º Andar, Chácara Santo Antônio, CEP 04710-230 São Paulo, SP, Brazil. E-mail: alexandre_pedroso@cargill.com

Luciano de Rezende Carvalheira

Thierry Ribeiro Tomich

Luiz Gustavo Ribeiro Pereira

Sandra Gesteira Coelho

SCIMAGO INSTITUTIONS RANKINGS

Tables

Tables (4)

Thumbnail

Table 1.
Ingredients and chemical composition of the evaluated diets.

Thumbnail

Table 2.
Intake and digestibility of nutrients consumed by lactating Holstein-Gyr dairy cows fed different crude protein (CP) concentrations.

Thumbnail

Table 3.
Milk production, components, and composition, as well as glucose and blood urea nitrogen, of lactating Holstein-Gyr dairy cows fed different crude protein (CP) concentrations.

Thumbnail

Table 4.
Nitrogen balance and nitrogen use efficiency in lactating Holstein-Gyr dairy cows fed different crude protein (CP) concentrations.

Table 1. Ingredients and chemical composition of the evaluated diets.

Item		Crude protein concentration (g kg^-1 DM)
Item		124	130	136	154
Ingredients (g kg^-1)
	Corn silage	530	533	540	536
	Ground corn	323	324	316	296
	Soybean meal	53	70	83	133
	Urea	0	29	57	87
	Soypass⁽¹⁾	68	44	29	0
	Sodium bicarbonate	7	7	7	7
	Mineral-vitamin supplement⁽²⁾	19	19	19	19
Chemical composition
	Dry matter (DM, g kg^-1 organic matter)	585	583	580	582
	Crude protein (g kg^-1 DM)	127	132	139	156
	Gross energy (kcal kg^-1)	3.96	3.95	3.94	3.94
	Non-fiber carbohydrates (g kg^-1 DM)	438	435	427	413
	Neutral detergent fiber (g kg^-1 DM)	358	355	356	353
	Acid detergent fiber (g kg^-1 DM)	162	161	161	161
	Ether extract (g kg^-1 DM)	33	33	33	33
	Rumen-degradable protein (g kg^-1 DM)⁽³⁾	56	67	77	97
	Rumen-undegradable protein (g kg^-1 DM)⁽³⁾	68	63	59	57
	Metabolizable protein (gram per day)⁽³⁾	1.88	1.88	1.88	1.88
	Net energy for lactation (Mcal kg^-1 DM)⁽³⁾	1.61	1.62	1.62	1.61

⁽¹⁾Lignosulfonate-treated soybean meal (Cargill, Uberlândia, MG, Brazil). ⁽²⁾Composition (kilogram of dry matter): 190 g Ca, 60 g P, 20 g S, 20 g Mg, 35 g K, 70 g Na, 15 mg Co, 700 mg Cu, 10 mg Cr, 700 mg Fe, 40 mg I, 1,600 mg Mn, 19 mg Se, 2,500 mg Zn, 200,000 IU vitamin A, 50,000 IU vitamin D3, 1,500 IU vitamin E, and 600 mg F. ⁽³⁾Estimated using the Cornell Net Carbohydrate and Protein System, version 6.1 (Fox et al., 2004FOX, D.G.; TEDESCHI, L.O.; TYLUTKI, T.P.; RUSSELL, J.B.; VAN AMBURGH, M.E.; CHASE, L.E.; PELL, A.N.; OVERTON, T.R. The Cornell Net Carbohydrate and Protein System model for evaluating herd nutrition and nutrient excretion. Animal Feed Science and Technology, v.112, p.29-78, 2004. DOI: 10.1016/j.anifeedsci.2003.10.006.
https://doi.org/10.1016/j.anifeedsci.200... ).

Table 2. Intake and digestibility of nutrients consumed by lactating Holstein-Gyr dairy cows fed different crude protein (CP) concentrations.

Item		CP concentration (g kg^-1 DM)				SEM⁽¹⁾	P-value⁽²⁾
Item		127	132	139	156	SEM⁽¹⁾	T	W	TxW
Intake
	DM (kg per day)	20.0	20.8	21.4	21.6	0.30	0.25	0.43	0.92
	CP (kg per day)	2.6	2.8	3.0	3.4	0.06	0.01⁽³⁾	0.23	0.78
	NDF (kg per day)	7.0	7.3	7.5	7.4	0.11	0.38	0.01	0.95
	ADF (kg per day)	3.1	3.1	3.2	3.1	0.06	0.83	0.01	0.99
	EE (kg per day)	0.7	0.7	0.7	0.7	0.01	0.60	0.01	0.95
	GE (Mcal per day)	78,952	81,978	84,213	84,440	1,209	0.34	0.11	0.93
Digestibility (%)
	DM	61.1	60.2	61.9	60.7	0.90	0.93	0.15	0.35
	CP⁽³⁾	58.2	60.7	62.9	67.2	1.00	0.04	0.16	0.23
	NDF	43.8	41.9	41.8	43.8	1.27	0.91	0.36	0.91
	ADF	34.2	31.5	31.5	35.0	1.50	0.81	0.98	0.86

⁽¹⁾Standard error of the mean. ⁽²⁾T, treatment effect; W, week effect; and TxW, treatment x week interaction. ⁽³⁾Linear effect (p≤0.01; y = 0.2619x - 0.6119; R²=0.98). DM, dry matter; NDF, neutral detergent fiber; ADF, acid detergent fiber; EE, ether extracts; and GE, gross energy.

Table 3. Milk production, components, and composition, as well as glucose and blood urea nitrogen, of lactating Holstein-Gyr dairy cows fed different crude protein (CP) concentrations.

Item	CP concentration (g kg^-1 DM)				SEM⁽¹⁾	P-value⁽²⁾
Item	127	132	139	156	SEM⁽¹⁾	T	W	TxW
Milk yield (kg per day)	24.5	22.4	24.0	23.8	0.22	0.54	0.07	0.12
4% fat corrected milk (kg per day)	23.9	21.5	23.7	22.8	0.22	0.34	0.18	0.17
Milk fat (%)	3.9	3.7	3.9	3.8	0.03	0.89	0.01	0.88
Milk fat (g)	955	834	955	862	10.32	0.23	0.03	0.31
Milk true protein (%)	3.3	3.2	3.4	3.3	0.02	0.82	<0.01	0.07
Milk true protein (g per day)	810	725	815	789	7.71	0.23	0.01	0.35
Milk lactose (%)	4.4	4.6	4.7	4.7	0.01	0.01⁽³⁾	0.03	0.23
Milk lactose (g per day)	1,085	1,030	1,132	1,121	10.19	0.46	0.02	0.18
Milk urea nitrogen (mg dL^-1)	8.1	12.2	14.4	18.5	0.32	0.01⁽⁴⁾	0.01	0.39
Glucose (mg dL^-1)	59.0	57.0	57.0	60.0	0.76	0.33	0.61	0.59
Blood urea nitrogen (mg dL^-1)	10.2	13.9	15.6	19.6	0.75	<0.01⁽⁵⁾	<0.01	0.06

⁽¹⁾Standard error of the mean. ⁽²⁾T, treatment effect; W, week effect; and TxW, treatment x week interaction. ⁽³⁾Quadratic effect (p≤0.01; y = -0.076x² + 2.2032x - 11.186, R²=0.99). ⁽⁴⁾Linear effect (p≤0.01; y = 3.2262x - 30.576, R²=0.93). ⁽⁵⁾Linear effect (p≤0.01; y = 3.2262x - 30.576, R²=0.93).

Table 4. Nitrogen balance and nitrogen use efficiency in lactating Holstein-Gyr dairy cows fed different crude protein (CP) concentrations.

Item	CP concentration (g kg^-1 DM)				SEM⁽¹⁾	P-value⁽²⁾
Item	127	132	139	156	SEM⁽¹⁾	T	W	TxW
N intake (g per day)	414	452	490	553	9.21	0.01	0.23	0.78
Milk N (g per day)	125	119	135	123	2.84	0.12	0.30	0.45
Fecal N (g per day)	178	179	182	180	4.93	0.99	0.54	0.39
Fecal N:N intake⁽²⁾	42	39	37.0	33	0.01	0.04	0.16	0.23
Urinary N (g per day)⁽³⁾	116	155	172	247	8.46	0.01⁽²⁾	0.21	0.21
Urinary N:N intake⁽²⁾	29	33	35	45	0.01	0.01	0.18	0.20
Microbial N	356	394	468	346	23.4	0.13	0.04	0.29
N efficiency⁽⁴⁾	29.8	26.5	27.5	22.4	0.006	0.01⁽²⁾	0.65	0.60

⁽¹⁾Standard error of the mean. ⁽²⁾T, treatment effect; W, week effect; and TxW, treatment x week interaction. ⁽²⁾Linear effect (p≤0.05; y = 42.143x - 400.64, R²=0.99). ⁽³⁾Predicted urinary N (gram per day) = N intake (gram per day) - milk N (gram per day) - fecal N (gram per day). ⁽⁴⁾Nitrogen use efficiency (%) = 100 × milk N (gram per day)/N intake (gram per day).

How to cite

copy

Embrapa Secretaria de Pesquisa e Desenvolvimento; Pesquisa Agropecuária Brasileira Caixa Postal 040315, 70770-901 Brasília DF Brazil, Tel. +55 61 3448-1813, Fax +55 61 3340-5483 - Brasília - DF - Brazil
E-mail: pab@embrapa.br

Acompanhe os números deste periódico no seu leitor de RSS

Versão para download de PDF

PDF

Inglês

Versões e tradução automática

Versão original do texto

English

Tradução automática

Google Translator
Microsoft Translator

Como citar

RIS

BIBTEX

Outros formatos de citação e exportação:

SciELO - Scientific Electronic Library Online
Rua Dr. Diogo de Faria, 1087 – 9º andar – Vila Clementino 04037-003 São Paulo/SP - Brasil
E-mail: scielo@scielo.org

Leia a Declaração de Acesso Aberto

Métricas

Reduction of crude protein in diets fed to lactating Holstein-Gyr cows

PlumX

Mensagem

[TFN1] ⁽¹⁾Lignosulfonate-treated soybean meal (Cargill, Uberlândia, MG, Brazil). ⁽²⁾Composition (kilogram of dry matter): 190 g Ca, 60 g P, 20 g S, 20 g Mg, 35 g K, 70 g Na, 15 mg Co, 700 mg Cu, 10 mg Cr, 700 mg Fe, 40 mg I, 1,600 mg Mn, 19 mg Se, 2,500 mg Zn, 200,000 IU vitamin A, 50,000 IU vitamin D3, 1,500 IU vitamin E, and 600 mg F. ⁽³⁾Estimated using the Cornell Net Carbohydrate and Protein System, version 6.1 (Fox et al., 2004FOX, D.G.; TEDESCHI, L.O.; TYLUTKI, T.P.; RUSSELL, J.B.; VAN AMBURGH, M.E.; CHASE, L.E.; PELL, A.N.; OVERTON, T.R. The Cornell Net Carbohydrate and Protein System model for evaluating herd nutrition and nutrient excretion. Animal Feed Science and Technology, v.112, p.29-78, 2004. DOI: 10.1016/j.anifeedsci.2003.10.006.
https://doi.org/10.1016/j.anifeedsci.200... ).