Twenty-eight Brangus cattle were used to determine the effect of copper and selenium supplementation on the carcass characteristics, fatty acid composition of the longissimus dorsi muscle and on the copper and selenium concentrations in the liver. The treatments were: no supplementation of copper or selenium; 2 mg Se/kg DM as sodium selenite; 40 mg Cu/kg DM as copper sulfate; and 2 mg Se/kg DM as sodium selenite and 40 mg Cu/kg DM as copper sulfate. The fat thickness, rib eye area and fatty acid composition of the longissimus dorsi muscle were not affected by treatments. There was no effect on carcass yield and cooling loss with the supplementation of copper, selenium or selenium × copper in the levels studied. For the ether extract concentration in the longissimus dorsi muscle, no differences were found according to the treatments with selenium, copper or selenium × copper. The treatments with selenium and selenium × copper showed higher selenium concentrations in the liver than the control and copper treatments. For the copper concentration in the liver, the copper and selenium × copper treatments showed higher values than the control and selenium treatments. Despite the little effect on the meat composition, the results of this experiment demonstrate no interaction between selenium and copper in the levels studied.

Foram utilizadas oito vacas Holandesas em lactação, distribuídas em um quadrado latino (4x4), replicado, num experimento conduzido durante o verão, por um período de 72 dias. O objetivo deste trabalho foi estudar quatro níveis de dietas catiônicas sobre a composição e as propriedades físico-químicas do leite em vacas após o pico de lactação. Para a manipulação do balanço cátion-aniônico da dieta (BCAD), foram adicionadas diferentes concentrações de bicarbonato de sódio nas dietas, obtendo-se os seguintes tratamentos: +150, +250, +400 e +500mEq kg-1 MS. Não houve diferença significativa para as variáveis: porcentagem de gordura, densidade e índice crioscópico do leite. O pH do leite aumentou linearmente e a acidez apresentou resposta cúbica com o aumento do BCAD.

Eight lactating Holsteins cows were distributed in a 4x4 replicated Latin square in the summer for 72 days. The objective of this research was to study the effect of four levels of cationic diets on the composition and physic-chemistries parameters of milk in cows after the lactation peak. For dietary cation anion balance manipulation, different concentrations of the sodium bicarbonate were added in the diets and the following treatments were obtainned: +150, +250, +400 e +500mEq kg-1 DM. The diets did not affect fat percentage and variables, density and crioscopic indice in the milk. Milk pH increased linearly and acidity decreased cubically with increased of dietary CAB.

O objetivo deste trabalho foi estudar o efeito do balanço cátion-aniônico da dieta (BCAD) no balanço e concentração sérica de cálcio em ovinos da raça Santa Inês. O delineamento experimental foi em blocos para controlar o efeito do peso inicial dos animais. Foram utilizados cinco tratamentos com níveis crescentes de BCAD (-160, -40, 140, 250 e 500mEq/kg de matéria seca) com cinco repetições em 25 animais. O BCAD influencia o metabolismo de cálcio em ovinos machos da raça Santa Inês. Com a diminuição do BCAD o cálcio sérico aumentou. Dietas aniônicas aumentaram a excreção urinária de cálcio, entretanto a retenção não foi afetada.

This work aimed at studing the effect of dietary cation-anionic balance (DCAB) in calcium balance and serum concentration in Santa Ines breed sheep. To control the effect of animals’ initial weight blocks were used as experimental design. Five treatments with increasing DCAB levels (-160, -40, 140, 250 and 500mEq/kg of dry matter) and five repetitions each were tested in 25 males. DCAB affected calcium metabolism of Santa Ines breed males. As DCAB lowered, serum calcium increased. Anionic diets raised urinary calcium excretion, however calcium retention wasn’t affected.