SciELO - Scientific Electronic Library Online

 
vol.40 issue2Crude protein contents in the concentrate ration and levels of supplementation for dairy cows grazing on brachiaria grass cv. marandu during the dry seasonInfluence of corn processing provided in the diet on the ruminal dynamics of dairy steer author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Revista Brasileira de Zootecnia

Print version ISSN 1516-3598

Abstract

SALES, Maykel Franklin Lima et al. Macromineral requirements by beef cattle under pasture supplementation. R. Bras. Zootec. [online]. 2011, vol.40, n.2, pp. 426-432. ISSN 1516-3598.  http://dx.doi.org/10.1590/S1516-35982011000200026.

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.

Keywords : calcium; nutritional requirement; phosphorus; supplementation; Zebu.

        · abstract in Portuguese     · text in English     · pdf in English