News reports indicate that 3,000 head of beef cattle died as a result of exposure to temperatures in the range of 44 to 50F.  The event occurred during mid-June in the state of Mato Grosso do Sul.  It’s difficult to ascribe the death of so many animals to hypothermia given the temperatures to which the herds were exposed.

Veterinary authorities in the state have apparently declined to respond to requests for an explanation.  Brazil has a reputation over their lack of transparency with respect to disease or mortality in livestock and poultry.

It is possible that mortality was attributed to a bacterial infection such as pasteurellosis precipitated by the rapid onset of cold weather. Cattle should be able to withstand temperatures to which they were apparently subjected even on pasture without shelter.