Marcus Antonio Zanetti

Suplementação de selênio e vitamina E sobre a contagem de células somáticas no leite de vacas da raça Holandesa

Selenium and vitamin E are important antioxidants for cells and tissues protection acting directly as a support for the udder health. This experiment was designed to evaluate the influence of prepartum selenium and vitamin E supplementation on milk somatic cell counts of Holstein cows. Eighty four animals were allocated into four treatments: control; supplementation with 5 mg Se/day; supplementation with 1000 UI vitamin E/day and supplementation with 5 mg Se/day + 1000 UI vitamin E/day. The supplementation started thirty days prior to probable parturition date until parturition. Forage and concentrate samples were taken every fifteen days for chemical, selenium and vitamin E analyses. Blood samples were taken before starting supplementation, right after parturition, thirty and sixty days after it to determine the selenium serum levels. Milk samples were taken to determine SCC. Selenium supplemented cows had higher serum selenium concentration compared with control group. The selenium decreased SCC up to 8th week of lactation playing an important role on immune response of bovine mamary gland.

Performance of steers fed different protein supplements in the mineral mixtures

Forty-eight crossbreed beef cattle were used to evaluate four commercial mineral supplements: Treatment ASalt + protein without urea (20% crude protein); B salt + protein with urea (52,5 % crude protein), C) mineralized salt; D) mineralized salt with urea (91% crude protein). The animals were distributed into 24 plots of Braquiaria decubens grass, with supplementation of (10.5 kg/an/day) of sugar cane, during 112 days, with 28 days of adaptation and 84 days of data collection. The animals were weighed at the beginning and at the end of the experiment, and the mineral supplement intake was weekly controlled. The weight gain and the mineral supplement intake (g/d) for the treatments A, B, C and D were 86 and 325, 357 and 650, -96 and 56, 207 and 135, respectively. The worst result was observed for the animals that received only mineralized salt and the best was obtaneid by the animals that received salt with protein with urea. The animals that received salt with protein without urea showed similar performance to the group that received only mineralized salt with urea.Forty-eight crossbreed beef cattle were used to evaluate four commercial mineral supplements: Treatment A- Salt + protein without urea (20% crude protein); B - salt + protein with urea (52,5 % crude protein), C) mineralized salt; D) mineralized salt with urea (91% crude protein). The animals were distributed into 24 plots of Braquiaria decubens grass, with supplementation of (10.5 kg/an/day) of sugar cane, during 112 days, with 28 days of adaptation and 84 days of data collection. The animals were weighed at the beginning and at the end of the experiment, and the mineral supplement intake was weekly controlled. The weight gain and the mineral supplement intake (g/d) for the treatments A, B, C and D were 86 and 325, 357 and 650, -96 and 56, 207 and 135, respectively. The worst result was observed for the animals that received only mineralized salt and the best was obtaneid by the animals that received salt with protein with urea. The animals that received salt with protein without urea showed similar performance to the group that received only mineralized salt with urea.

Effects of copper and selenium supplementation on performance and lipid metabolism in confined brangus bulls.

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.

Substituição do milho em grão moído pela polpa cítrica na desmama precoce de bezerros leiteiros

The present study was carried out to study the substitution of the ground corn grain by the dried citrus pulp in the starter diet of 28 Holstein calves in an early weaning system. The experimental design was in completely randomized blocks, with the blocks formed in accordance to the arrival order of the animals. The animals were slaughter at the end of the experiment. The experiment consisted on four treatments: 0, 15, 30 and 45% of citrus pulp in the diet, in substitution of the ground corn grain. The calves received the colostrum for three days in the original farm. Besides the concentrate, the calves received four liters of whole milk in the first month, divided in two meal, and three liters in the second month. The concentrate was fed ad libitum fed to the calves from the fourth life day. All calves were kept in individual houses. The evaluated parameters were: average daily gain, dry matter intake, feed:gain ratio, increases of the withers height and of the heart girth, volume and weight of the stomach compartments, development of rumen papillas, number of protozoa, pH and incidence of diarrhea. There was no significant difference among treatments. The dried citrus pulp can substitute the ground corn grain in the diet of early weaned calves, with good results.

Influência da diferença cátion-aniônica da dieta sobre o balanço de cálcio, fósforo e magnésio em ovinos

The dietary cation-anion balance (DCAB) effect on the macromineral (calcium, phosphorus and magnesium) balance, urinary and faecal pH, serum concentration of calcium, phosphorus and magnesium was studied in 16 Santa Ines adult sheep, during 26 days, being a seven-day-period of adaptation. The experiment consisted in a completely randomized block design with four treatments. Calcium chloride and sodium bicarbonate were added to DCAB manipulations to achieve the values: -12; + 30; +76 and +133mEq/kg DM. There was no effect of DCAB (P>0.10) on fecal and urinary pH, and on phosphorus and magnesium balance. The increase in the DCAB corresponded to a decrease in calcium absorption and calcium retention, and an increase in calcium fecal excretion values. The manipulation of the DCAB affected the macromineral metabolism, mainly the calcium metabolism.

Effects of Dietary Selenium, Sulphur and Copper Levels on Selenium Concentration in the Serum and Liver of Lamb

Thirty-two lambs were distributed in eight treatments under 2×2×2 factorial experiment to compare the effects of two levels of selenium (0.2 to 5 mg/kg dry matter [DM]), sulphur (0.25% and 0.37%) and copper (8 and 25 mg/kg DM) levels on selenium concentration in liver and serum of lambs. A liver biopsy was done on all animals and blood samples were collected from the jugular vein prior to the beginning of the treatments. The blood was sampled every thirty days and the liver was sampled after 90 days, at the slaughter. Increasing differences were noticed during the data collection period for the serum selenium concentration, and it was found to be 0.667 mg/L in animals fed with 5 mg Se/kg DM and normal sulphur and copper concentrations in their diet. However, a three-way interaction and a reduction of selenium concentration to 0.483 mg/L was verified when increasing copper and sulphur concentration levels to 25 ppm and 0.37% respectively. The liver selenium concentration was also high for diets containing higher selenium concentrations, but the antagonist effect with the increased copper and sulphur levels remained, due to interactions between these minerals. Therefore, for regions where selenium is scarce, increasing its concentration in animal diets can be an interesting option. For regions with higher levels of selenium, the antagonistic effect of interaction between these three minerals should be used by increasing copper and sulphur dietary concentrations, thus preventing possible selenium poisoning.

Changes in ruminal fermentation and mineral serum level in animals kept in high temperature environments

Para verificar o efeito da temperatura ambiente na fermentacao ruminal do alimento e nas concentracoes de minerais em bovinos em crescimento, foram utilizados 12 bezerros machos (peso medio inicial de 82,9 ± 7,7 kg com 100 dias de idade), durante 38 dias, em delineamento experimental de blocos ao acaso, com medidas repetidas no tempo e duas temperaturas ambiente: ambiente termoneutro (24oC) e ambiente de estresse por calor (33oC). Os animais expostos a temperatura de 33oC tiveram ingestao menor de materia seca, menor nivel serico de T3 (triiodotironina), maior concentracao de nitrogenio amoniacal (NH3-N) no liquido ruminal e maior temperatura retal e corporal em todo o periodo experimental em comparacao aqueles animais mantidos no ambiente termoneutro (24oC). Os animais em ambiente de estresse por calor (33oC) apresentaram maior concentracao de calcio no soro, que foi maior aos 31 dias de experimentacao e menor aos 38 dias. A concentracao de fosforo nesses animais foi menor durante todo o periodo experimental e a de sodio, menor aos 17, 31 e 38 dias de experimentacao. As concentracoes de potassio e zinco foram menores depois de 24 dias; a de cobre menor ate 24 dias; e a de magnesio maior ate 17 dias de experimentacao, todas em comparacao a dos animais mantidos em ambiente termoneutro (24oC). Os animais sob estresse por calor apresentaram maiores concentracoes de nitrogenio amoniacal no liquido ruminal e diminuicao nas concentracoes sericas de fosforo, sodio, potasseio e zinco. Sao necessarias mudancas no manejo alimentar de ruminantes em temperaturas acima do conforto termico, para diminuir as perdas no desempenho.

Effect of supplementation of two sources and two levels of copper on lipid metabolism in Nellore beef cattle.

UNLABELLED This study was conducted with 35 Nellore beef cattle to determine the effect of supplementation of two levels and two copper sources (organic and inorganic) on metabolism of lipids and cholesterol of meat. The five treatments used were: CONTROL 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.

Contagem de células somáticas no leite de vacas suplementadas no pré-parto com selênio e vitamina E

Selenium and vitamin E are important antioxidants for cells and tissues protection acting directly as a support for the udder health. This experiment was aimed at evaluating the influence of prepartum selenium and vitamin E supplementation on milk somatic cell counts of Holstein cows during summer period. Eighty animals were allocated into four treatments: control; supplementation with 2.5mg Se day-1; supplementation with 1000 UI vitamin E day-1 and supplementation with 2.5mg Se day-1 + 1000 UI vitamin E day-1. The supplementation started thirty days before the probable parturition date until parturition. Forage and concentrate samples were taken every fifteen days for chemical and selenium analyses. Blood samples were taken before starting supplementation, right after parturition, thirty and sixty days after it to determine the selenium serum levels. Milk samples were taken to determine somatic sell count (SCC). Selenium supplemented cows had higher serum selenium concentration compared with control group (P 0.05) SCC up to 12th week of lactation.

Copper and selenium supplementation in the diet of Brangus steers on the nutritional characteristics of meat

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.