| Registro completo |
| Provedor de dados: |
PAB
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| País: |
Brazil
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| Título: |
Reduction of crude protein in diets fed to lactating Holstein-Gyr cows
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| Autores: |
Guimarães,Clóvis Ribeiro
Azevedo,Rafael Alves de
Campos,Mariana Magalhães
Machado,Fernanda Samarini
Pedroso,Alexandre Mendonça
Carvalheira,Luciano de Rezende
Tomich,Thierry Ribeiro
Pereira,Luiz Gustavo Ribeiro
Coelho,Sandra Gesteira
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| Data: |
2018-07-01
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| Ano: |
2018
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| Palavras-chave: |
Nitrogen
Protected soybean meal
Soypass
Urea
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| Resumo: |
Abstract: 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.
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| Tipo: |
Info:eu-repo/semantics/article
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| Idioma: |
Inglês
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| Identificador: |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2018000700858
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| Editor: |
Embrapa Secretaria de Pesquisa e Desenvolvimento
Pesquisa Agropecuária Brasileira
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| Relação: |
10.1590/s0100-204x2018000700010
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| Formato: |
text/html
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| Fonte: |
Pesquisa Agropecuária Brasileira v.53 n.7 2018
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| Direitos: |
info:eu-repo/semantics/openAccess
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