Outbreaks of Brachiaria ruziziensis and Brachiaria brizantha intoxications in Brazilian experienced cattle.

Brachiaria species are some of the most used forage species for raising Brazilian cattle because of their great nutritional value and adaptability to the tropical climate. However, cases of animal intoxication have been described. Animal species, age, genetic resistance, and previous adaptation to the forage can influence the susceptibility to intoxication. Cattle (young or adults), other adult ruminants and animals adapted to consumption (experienced flocks) are considered more resistant. The main clinical presentation is that of hepatogenous photosensitization. Brachiaria brizantha and Brachiaria ruziziensis are considered less toxic. The aim of this study is to describe three outbreaks of intoxication by B. brizantha and B. ruziziensis in experienced cattle, as well as to compare the concentrations of protodioscin in paddocks with and without clinical cases. It was observed that the two forage species are toxic to all age groups of cattle adapted to their consumption, and the concentrations of protodioscin present in the plant cannot be used as the only criterion for determining the occurrence of intoxication.

Poisoning of calves reared with cows treated with abamectin.

The aim of the present study was to describe an outbreak of poisoning by abamectin in calves less than four months of age whose mothers were treated with a pour-on product containing this ingredient. The diagnosis was based on the history, clinical signs, absence of macroscopic and histopathological findings (characteristic of this type of poisoning) and the detection of abamectin in tissues of the animals submitted to necropsy. Based on this report, the recommendation is the use with caution of pour-on formulations containing abamectin on cows having given birth less than four months earlier.