Twenty-eight Brangus cattle were used to determine the effect of copper and selenium supplementation on performance, feed efficiency, composition of fatty acids in Longissimus dorsi (LD) muscle, and cholesterol concentration in serum and in LD muscle and enzymes activities, reduced glutathione (GSH) and oxidized glutathione (GSSG). The treatments were: i) Control, without copper (Cu) and selenium (Se) supplementation; ii) Se, 2 mg Se/kg of dry matter such as sodium selenite; iii) Cu, 40 mg Cu/kg of dry matter such as copper sulfate; iv) Se/Cu, 2 mg Se/kg of dry matter such as sodium selenite and 40 mg Cu/kg of dry matter such as copper sulfate. LD muscle fatty acid composition was not influenced by the treatments (p>0.05). The serum concentration of cholesterol was not influenced by the treatments (p>0.05), however, the concentration of cholesterol in LD was lower in cattle supplemented with copper and selenium (p<0.05). Oxidized glutathione and reduced glutathione increased (p<0.05) with Cu, Se and Se/Cu supplementation. The supplementation of copper (40 mg/kg DM) and selenium (2 mg/kg DM) altered the metabolism of lipids in confined Brangus cattle, through a decrease in cholesterol deposition in the LD, possibly by changing the ratio between reduced glutathione/oxidized glutathione. Copper and selenium supplementation improved animal performance and feed efficiency (p<0.05) when compared to the control group, providing advantages in the production system, while also benefiting consumers by reducing cholesterol concentration in the meat.

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without copper supplementation, I10 or I40: 10 or 40 mg/kg DM (as Cu sulfate), O10 or O40: 10 or 40 mg/kg DM (as Cu proteinate). In general, the copper supplementation changed the fatty acid profile of meat (p<0.05), with a higher proportion of unsaturated fatty acids and reduction of saturated fatty acids. There was no effect of supplementation on blood cholesterol and triglycerides, however; in general, there was a reduction in cholesterol concentration in the L. dorsi (p<0.05) compared to the control treatment through the reduction (p<0.05) in the concentrations of GSH and GSH/GSSG ratio. The Cu supplementation did have an influence on metabolism of lipids. The production of healthier meat is beneficial to public health by reducing the risk of cardiovascular disease.

RESUMO -Quatro bubalinos e quatro bovinos adultos com fístulas ruminais foram utilizados com o objetivo de se estudar os efeitos de diferentes níveis de fibra em detergente neutro na dieta sobre as características digestão ruminal. Foram avaliadas as degradabilidades da matéria seca, fibra em detergente neutro do feno de coastcross e do farelo de trigo, matéria seca do milho em grãos moídos e do farelo de soja; digestibilidade com indicador (Cr 2 O 3 ). Os animais foram delineados em dois quadrados latinos (4x4) com arranjo fatorial 4x2, sendo quatro níveis crescentes de FDN na MS (54, 60, 66 Effects of the Increasing Levels of Neutral Detergent Fiber in the Diet on the Digestion in Water Buffaloes and CattleABSTRACT -Four buffaloes and four cattle rumen fistulated were used with the objective to study the effects of different levels of neutral detergent fiber in the diet on the digestion characteristics. The In situ degradations of dry matter (DM), neutral detergent fiber (NDF) of the coastcross hay and wheat meal, DM of the corn ground and soybean meal were evaluated. The digestibilities of DM, crude protein and NDF of the diets were also evaluated using a Cr 2 O 3 as a marker. The animals were allotted to two in a 4x2 factorial arrangement with four increasing levels of NDF in the DM (54, 60, 66 and 72%) and two animal species (buffaloes and cattle). Four twenty-nine days subperiods were used, with 13 days for diet adaptation. The buffaloes showed higher ruminal DM and NDF disappearance of the Coast-cross hay and soybean meal DM than cattle, in most of the incubation times. On the other hand, the ruminal NDF disappearance of wheat meal was higher for the cattle only in the first hours. There was interaction between species and NDF levels for the DM digestibility coefficients. The NDF levels influenced the NDF digestibility coefficient and it was not noticed effects of species or NDF levels for the CP digestibility coefficient. IntroduçãoA fibra e a proteína consumidas pelos ruminantes, obtidas de diferentes fontes e variadas composições, têm influência na atividade microbiana no rúmen. Há indícios de que forragens de baixa qualidade são melhores aproveitadas pelos bubalinos que pelos bovinos (RAZDAN et al., 1971;NOGUEIRA FILHO, 1995).A degradabilidade das frações fibrosas de alimentos volumosos cresce com o aumento da proporção de volumoso na dieta (CHIMWANO et al., 1976). HOPSON et al. (1963)

RESUMOO efeito do balanço cátion-aniônico da dieta (BCAD) no balanço macromineral (cálcio, fósforo e magnésio), no pH urinário e fecal, na concentração sérica de cálcio, fósforo e magnésio foi estudado utilizando-se 16 carneiros machos, da raça Santa Inês, por um período de 26 dias, sendo sete de adaptação. O delineamento experimental foi em blocos ao acaso, com quatro tratamentos. Para a manipulação do BCAD foram adicionados cloreto de cálcio e bicarbonato de sódio, obtendo-se os seguintes tratamentos: -12; +30; +76 e +133mEq/kg MS da ração. Não foram encontradas diferenças (P>0,10) no pH fecal, pH urinário, balanço de fósforo e magnésio. Com o aumento do BCAD houve decréscimo da absorção e retenção de cálcio, e aumento da excreção fecal. A manipulação do BCAD interferiu no metabolismo de macrominerais, principalmente no de cálcio.

-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.

-Two experiments were carried out with twenty-four male weaned Holstein calves to verify the influence of different dietary cation-anion concentrate and roughage proportions on calves metabolism. In the first experiment, calves were fed rations with -100, +200 and +400 mEq cation-anion balance/kg of dry matter, containing 60% of roughage and 40% of concentrate. In the second experiment, calves (117.6±20.8 kg average weight) received rations with similar dietary cation-anion balance but in diets of 40% roughage and 60% concentrate. As the dietary cation-anion balance became more positive, there was a quadratic response of blood pH in both diets with 60 and 40% roughage. A linear increase following increased dietary cation-anion balance was observed on bicarbonate concentration, carbon dioxide tension, carbon dioxide partial pressure and urine pH on both experiments, while anion gap decreased linearly. Blood urea nitrogen and base excess increased quadratically according to increased dietary cation-anion balance on 60% roughage, whereas those same parameters showed a linear increase on 40% roughage. Growing ruminant metabolism both in cationic and anionic diets was modified when the roughage:concentrate ratio was altered.

Estudaram-se os efeitos do método de colheita de líquido ruminal, por sonda ou fístula ruminal, e do momento de colheita, antes e depois da alimentação, sobre a concentração e proporção de AGVs, concentração de nitrogênio amoniacal, concentração de minerais e pH do líquido ruminal, utilizando-se quatro bovinos machos da raça Nelore, com fístula ruminal e peso médio de 237kg. Observou-se maior concentração total de ácidos graxos voláteis no líquido colhido por fístula antes e depois da alimentação. Maior porcentagem de ácido acético, menor de ácido propiônico e butírico, menor concentração de nitrogênio amoniacal, maior valor do pH e menor concentração de cálcio, de fósforo e de potássio foram obtidas no líquido colhido por sonda esofagiana. Tanto o líquido ruminal colhido por fístula como o por sonda esofagiana antes da alimentação apresentaram menor concentração de AGVs, menor porcentagem de ácido propiônico, menor concentração de nitrogênio amoniacal, maior porcentagem de ácido butírico, maior relação AC/PRO e maior pH do que o colhido após a alimentação. Sugere-se trabalhar com colheitas por fístula ruminal após a administração do alimento em experimentos em que se queira observar os primeiros efeitos dos tratamentos sobre o metabolismo ruminal. Com conhecimento prévio da ação do tratamento no metabolismo ruminal e sendo utilizado um tratamento-controle, a colheita por sonda esofagiana poderá ser utilizada, mas apenas para experimentos em que os parâmetros ruminais sejam o enfoque secundário.