Hepatic photosensitization in buffaloes intoxicated by Brachiaria decumbens in Minas Gerais state, Brazil.

The aim of this paper is to report the study of hepatogenous photosensitization in buffaloes during two outbreaks provoked by ingestion of Brachiaria decumbens in Minas Gerais state, Brazil. Ten young buffaloes in outbreak 1 and seven buffaloes in outbreak 2 were intoxicated by B. decumbens. Nine clinically healthy buffaloes raised under the same conditions as the sick animals served as the control group. All animals were subjected to clinical examination, and serum was collected to measure gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), direct bilirubin (DB), indirect bilirubin (IB) and total bilirubin (TB) as indicators of liver function and urea and creatinine as indicators of renal function. Histopathology of liver fragments from five different animals was carried out. During the outbreaks and every two months for one year, samples of grass from paddocks where the animals got sick were collected for quantitative evaluation of the saponin protodioscin, combined with observations of pasture characteristics and daily rainfall. Clinical signs included apathy, weight loss, restlessness, scar retraction of the ears and intense itching at the skin lesions, mainly on the rump, the tail head, neck and hindlimbs, similar to the signs observed in other ruminants. Only the GGT enzyme presented significantly different (P < 0.01) serum levels between intoxicated animals (n = 17) and healthy animals (n = 9), indicating liver damage in buffaloes bred in B. decumbens pastures. Microscopy of the liver showed foamy macrophages and lesions of liver disease associated with the presence of crystals in the bile ducts, which have also been found in sheep and cattle poisoned by grasses of the genus Brachiaria. During the outbreaks, protodioscin levels were higher than 3%, and shortly after, these levels were reduced to less than 0.80%, suggesting a hepatic injury etiology. The outbreaks took place at the beginning of the rainy season, and there was a positive correlation between saponin and the amount of rainfall, as well as between saponin and the amount of green leaves in the pasture. These findings indicate that the grass was more toxic in this period. This is the first report of photosensitization by B. decumbens in buffalo.

Extração de DNA e avaliação da composição espécie-específica de queijos / DNA extraction and evaluation of the specie-specific composition of cheeses

Foram testados três métodos de extração de DNA em amostras de queijo, com o objetivo de identificar uma técnica eficiente para extração de DNA em amostras com várias limitações, como alto teor de gordura, alto grau de degradação do DNA e grande concentração de impurezas. A técnica que faz uso do tiocianato de guanidina mostrou-se mais adequada para identificação de adição intencional não declarada de leite bovino em queijos bubalinos, podendo ser empregada para certificação de produto específico (selo de Identidade de Espécie).

Three methods of DNA extraction were tested in cheese samples. The objective of this study was to identify an efficient technique for DNA extraction in different samples with several limitations, such as high fat tenor, high degree of DNA degradation and great sludge concentration. The technique using Guanidine thiocyanate was more appropriate for identification of intentional undeclared addition of bovine milk in buffalo cheeses. This technique can be used for certification of a specific product (stamp of Identity of Species).