Orientador: Alexandre Secorun Borges / Banca: Márcio Rubens Graaf Kuchembuck / Banca: Ivan Roque de Barros Filho / Resumo: O presente trabalho teve como objetivo determinar os elementos minerais no soro sangüíneo (magnésio, cobre, selênio, zinco, fósforo, cálcio, potássio, ferro) e no tecido hepático (cobalto, cobre, selênio, manganês, molibdênio e zinco) em seis diferentes momentos durante um período de dezesseis meses e verificar se houve variação entre eles. Foram utilizadas 25 novilhas mestiças Nelore, com idade média de 18 meses, que permaneceram durante todo o tempo do experimento no mesmo pasto de Brachiaria brizantha. Os animais ainda receberam mistura mineral comercial em cocho coberto e água à vontade e foram submetidos à coleta de fragmentos hepáticos e sangue para obtenção de soro. Análises da pastagem também foram realizadas nos mesmos momentos em que foram colhidas as amostras de soro e fígado (exceto em fevereiro 2003). A água e o sal mineral também foram analisadas. Os níveis médios dos elementos no tecido hepático foram, respectivamente para as seis diferentes colheitas: Co 0,27;0,27; 0,23;0,21; 0,23 e 0,24 ppm; Mn 9,07; 8,55; 8,67; 8,40; 7,90 e 7,25 ppm; Mo 4,18; 3,85; 3,68; 3,32; 3,54; 3,19 ppm; Zn 113,4; 101,94; 97,91; 92,46; 88,29 e 81,74 ppm; Cu 40,76; 36,33; 24,50; 24,70; 77,75 e 128,03 ppm e Se 0,86; 1,09; 0,72; 1,21; 0,91 e 0,75 ppm. Destes, os níveis de Co, Mn, Mo, Se e Zn foram considerados adequados para bovinos. Os níveis médios dos elementos no soro foram, para as quatro diferentes colheitas: Ca 118,72; 129,36; 125,19; 112,90; 96,76; 85,37 mg/L; P 109,28; 106,30; 117,03; 103,39; 115,78 e 107,75 mg/L; Mg 19,75; 23,62; 26,54; 20,96; 20,80 e 23,12 mg/L; K 139,64; 134,85; 114,19; 131,65; 130,57 e 116,60 mg/L; Cu 0,52; 0,73; 0,41; 0,59; 0,60 e 0,73 mg/L; Zn 1,19; 1,87; 1,38; 1,13;1,28 e 1,37 mg/L; Fe 2,52; 3,44; 2,21; 3,08; 3,00 e 2,89 mg/L e Se 1,19; 1,87; 0,19; 0,44, 0,40 e 0,51 mg/L...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of the present work was to determinate the mineral levels in beef cattle blood serum (magnesium, copper, selenium, zinc, phosphorus, calcium, potassium, iron) and liver (cobalt, copper, selenium, manganese, molibdenium and zinc) at six different moments throughout sixteen months, to verify the occurrence of variation among them. Twenty-five half-breed nelore heifers, all of them about 18 months old, stayed during the experiment in the same Brachiaria brizantha pasture. They also received commercial mineral mixture in appropriate feeders and free acess to water. Pasture were also analised at the same moments we did for serum and liver (except february 2003). Water and mineral mixture were analised as well. The average levels of the elements in the liver, respectively for the six different moments: Co 0.27,0.27, 0.23, 0.21, 0.23 and 0.24 ppm; Mn 9.07, 8.55, 8.67, 8.40, 7.90 and 7.25 ppm; Mo 4.18, 3.85, 3.68, 3.32, 3.54, 3.19 ppm; Zn 113.4, 101.94, 97.91, 92.46, 88.29 and 81.74 ppm; Cu 40.76, 36.33, 24.50, 24.70, 77.75 and 128.03 ppm and Se 0.86, 1.09, 0.72, 1.21, 0.91 and 0.75 ppm. The levels of Co, Mn, Mo, Se and Zn were considered appropriate for cattle. The average levels of the elements in the serum were, for the six different moments: Ca 118.72, 129.36, 125.19, 112.90, 96.76, 85.37 mg/L; P 109.28, 106.30, 117.03, 103.39, 115.78 and 107.75 mg/L; Mg 19.75, 23.62, 26.54, 20.96, 20.80 and 23.12 mg/L; K 139.64, 134.85, 114.19, 131.65, 130.57 and 116.60 mg/L; Cu 0.52, 0.73, 0.41, 0.59, 0.60 and 0,73 mg/L; Fe 2,52; 3,44; 2,21; 3,08; 3,00 and 2,89 mg/L; Se 1.19, 1.87, 0.19, 0.44, 0.40 and 0.51 mg/L and Zn 1.19, 1.87, 1.38, 1.13,1.28 and 1.37 mg/L. In the serum, Ca, P, Mg, Zn, Fe and Se levels were considered appropriate for beef cattle. There was correlation between the hepatic and serum levels of Cu...(Complete abstract, click electronic address below) / Mestre