Data/hora: 11/06/2024 00:43:28

Provedor de dados: 	86	
País: 	Brazil	
Título: 	Reduction of crude protein in diets fed to lactating Holstein-Gyr cows	
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.	
Data: 	2018-07-01	
Ano: 	2018	
Palavras-chave: 	Nitrogen; Protected soybean meal; Soypass; Urea.	
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.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2018000700858	
Editor: 	Embrapa Secretaria de Pesquisa e Desenvolvimento

Pesquisa Agropecuária Brasileira	
Relação: 	10.1590/s0100-204x2018000700010	
Formato: 	text/html	
Fonte: 	Pesquisa Agropecuária Brasileira  v.53 n.7 2018	
Fonte: 	info:eu-repo/semantics/openAccess