Macromineral requirements by beef cattle under pasture supplementation.

• Autor(a) principal: SALES, M. F. L.
• Data de Publicação: 2011
• Outros Autores: PAULINO, M. F., VALADARES FILHO, S. de C., PORTO, M. O., COUTO, V. R. M., PAULINO, P. V. R.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice)
• Texto Completo: http://www.alice.cnptia.embrapa.br/alice/handle/doc/902535
• topic: Beef steer; Becerros castrados; Cebú; Ganado de carne; Nutrición animal; Pastizales; Pastos forrajeros; Suplementos dietéticos minerales; Gado de corte; Gado Zebu; Novilho de corte; Nutrição animal; Pastagem; Gramínea forrageira; Capim Brachiaria; Brachiaria decumbens; Suplemento mineral; Cálcio; Fósforo; Magnésio; Sódio; Potássio; Beef cattle; Zebu; Steers; Animal nutrition; Pastures; Forage grasses; Dietary mineral supplements; Calcium; Phosphorus; Magnesium; Sodium; Potassium

The objective of this work was to determine macromineral requirements by Zebu steers grazing Brachiaria decumbens supplemented with concentrate. It was used 24 non-castrated steers, at an average age of 7 months and at initial average weight 180 kg. Eight control animals were slaughtered for determining initial body composition. The 16 remaining animals were divided in four four-animal plots, in a complete random design. Each plot received mineral mixture or supplements at the levels 0.75; 1.50 or 2.25 kg/animal/day. The right half-carcass of eight animals, two per group, was dissected in muscle, fat and bones and all body constituents were weighted for determination of empty body weight and body composition. Net requirements of calcium and phosphorus for an animal at 400 kg body weight were 11.13 g and 5.40 g, respectively. To estimate dietary requirements of maintenance and after, sum them to dietary requirements for gain in order to obtain total dietary requirements, it was adopted endogenous losses and bioavailability present in literature for each mineral macroelement. Total dietary requirement for calcium, phosphorus, magnesium, sodium and potassium for a 400-kg BW animal with 1.0-kg daily weight gain were 34.59; 17.36; 7.82; 5.19 and 41.11 g/day, respectively. Macromineral requirements by beef cattle under pasture supplementation are similar to those recommended by BR-Corte for beef cattle in feedlots.