Título:	Energy and protein requirements of young Holstein calves in tropical condition.
Autoria:	RODRIGUES, J. P. P. LIMA, J. C. M. CASTRO, M. M. D. VALADARES FILHO, S. de C. CAMPOS, M. M. CHIZOTTI, M. L. MARCONDES, M. I.
Afiliação:	João Paulo Pacheco Rodrigues, UFV; Jessika Carolina Moutinho Lima, UFV; Marcelo Messias Duarte Castro, UFV; Sebastião de Campos Valadares Filho, UFV; MARIANA MAGALHAES CAMPOS, CNPGL; Mário Luiz Chizzotti, UFV; Marcos Inácio Marcondes, UFV.
Ano de publicação:	2016
Referência:	Tropical Animal Health and Production, n. 48, p. 1387-1394, 2016.
Conteúdo:	Our objective was to estimate the energy and protein requirements of Holstein young calves up to 87 days old. Forty-two Holstein calves aged 4 days were used. From these, ten were randomly selected and slaughtered to compose the baseline slaughter (BS) group. The remaining calves were randomly assigned to eight treatments in a 4 × 2 factorial using a completely randomized design. The treatments were 2, 4, 6, and 8 kg/day of milk (297 g/kg CP; 319 g/kg of fat) fed twice daily, and then harvested at 59 or 87 days of age. Calves were fed a starter (193 g/kg CP; 133 g/kg NDF) ad libitum in all treatments. The calves slaughtered at 87 days of age had milk replaced by Coast-cross (Cynodoon sp.) hay (125 g/kg CP; 728 g/kg NDF). The net requirement of energy for maintenance (NEm) was 0.36 MJ/kg EBWG, with efficiency of utilization of energy for maintenance (km) of 59.4 %. The equation obtained to estimate the net requirement of energy for gain (NEg; MJ/d) was 4.40 × EBW0.099, with the efficiency of utilization of energy for gain (kg) equal to 46.5 %. The observed requirements of net and metabolizable protein for maintenance (NPm and MPm) were 3.67 and 3.88 g/kg BW0.75, respectively. The efficiency of use of metabolizable protein for maintenance (kpm) was 94.6 %. The predicted requirements were higher than those observed in the literature, and this study demonstrated that the requirements of newborn calves are higher than the recommended.
NAL Thesaurus:	Dairy calves Holstein Slaughter metabolizable energy
Palavras-chave:	Comparative slaughter Efficiency of utilization Growth Maintenance Metabolizable protein
Tipo do material:	Artigo de periódico
Acesso:	openAccess
Aparece nas coleções:	Artigo em periódico indexado (CNPGL)