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.

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.

Probiotics association in the suckling and nursery in piglets challenged with Salmonella typhimurium

This work aimed to study the probiotics association in 144 piglets from birth to 62 days old. In lactation, the design was completely randomized with two treatments, CTL, 1 mL of distilled water and ProbA, 5g in 15 ml of distilled water, both orally, and in the nursery in randomized block design, with 2x3 factorial arrangement of treatments, ProbA ProbB: 30g/ton of ProbB in the ration; CTL ProbB: 30g/ton of ProbB in the ration; ProbA ProbA, CTL CTL; ProbA CHA (challenged); CTL CHA. At 35 days of age the animal of the nursery were inoculated with Salmonella typhimurium orally. There was no effect of the parameters evaluated during the maternity. In nursery, the feed conversion was favorable to the ProbA. In the evaluation of fecal score, the challenged group had more diarrhea and increased elimination of S. typhimurium. Results showed the positive action of probiotics when applied at birth by the direct influence on the formation of the intestinal microbiota.

Efeito da substituição do farelo de soja pela amiréia 150S no consumo, produção e composição do leite / Effect of the substitution of the soybean meal for the starea 150S in the intake, production and composition of the milk

Doze vacas leiteiras (³/4 Holandês x ¹/4 Gir) foram utilizadas em um delineamento em quadrado latino, nas dependências da Fazenda Raposo - Nepomuceno, MG, entre novembro de 2001 e abril de 2002 para comparar o efeito da substituição parcial e total do farelo de soja pela amiréia na produção e composição do leite. Os animais apresentavam peso médio de 443 kg e estavam na quarta lactação. A amiréia substituiu o farelo de soja nas seguintes proporções: 0 - 0 por cento de amiréia 150 S; 33 - 33 por cento de amiréia 150 S; 66 - 66 por cento de amiréia 150 S e 100 - 100 por cento de amiréia 150 S, sendo que todos tratamentos foram isoenergéticos e isoprotéicos. Utilizou-se a cana-de-açúcar (Saccharum officinarum L.) como volumoso "ad libitum". Cada período experimental teve duração de 15 dias, 9 dias para adaptação e 6 dias para coleta de dados. A produção de leite de cada vaca foi pesada nas duas ordenhas (manhã e tarde) e as amostras enviadas para análise de gordura, proteína, lactose, sólidos totais e uréia, pelo processo de infravermelho, junto à Clínica do Leite do Departamento de Produção Animal da ESALQ/USP. A gordura e sólidos totais do leite não foram influenciados pelos tratamentos (P>0,05). A produção de leite, a proteína, a lactose e a uréia do leite diferiram entre os tratamentos (P<0,05). Conclui-se que, nas condições deste experimento, é viável a substituição total do farelo de soja pela amiréia.

Twelve dairy cows (³/4 Hoslten x ¹/4 Gir) were used in a desing in Latin square, at Fazenda Raposo's dependences in Nepomuceno, MG, between November of 2001 and April of 2002 to compare the effect of the partial and total substitution of soybean meal for starea in the production and composition of milk. The medium weight of the animals was 443 kg and they were in the fourth nursing. The starea substituted soybean meal in the following proportions: 0 - 0 percent of starea 150 S; 33 - 33¨ percent of starea 150 S; 66 - 66 percent of starea 150 S and 100 - 100 percent of starea 150 S, and every treatments were isoenergetics and isoproteics. Sugar-cane (Saccharum officinarum L.) was used ad libitum as roughage. Each experimental period had the duration of 15 days being 9 days for adaptation and 6 days for collection of data. The milk production of each cow was weighed twice a day (morning and afternoon) and samples were sent for analysis of fat, protein, lactose, total solids and urea, by the infrared method, at the Clinic of the Milk of the Department of Animal Production at ESALQ/USP, in Piracicaba, SP. Fat and total solids of milk were not influenced by the treatments. The production of milk, protein, lactose and urea content of milk differed among the treatments (P<0.05). The results showed that it is viable the total substitution of soybean meal for starea.