Recent investigations by the Australian Department of Agriculture, Fisheries and Forestry into high mortalities on live export voyages from Australia to the Middle East during the Northern hemisphere summer suggest that animal welfare may be compromised by heat stress.
The live export industry has generated a computer model that aims to assess the risk of heat stress and to contain mortality levels on live export ships below certain arbitrary limits.
Although the model must be complied with under Australian law, it is not currently available for independent scientific scrutiny, and there is concern that the model and the mandated space allowances are inadequate.
This review appraises the relevant literature on heat stress in sheep and cattle, including laboratory studies aimed at mimicking the ambient temperatures and humidity levels likely to be encountered on live export voyages.
Animal welfare is likely to be very poor as a result of heat stress in some shipments. The study is from Vets Against Live Export, Flinders Island, Tasmania, Australia and the Faculty of Veterinary Science, University of Sydney, Sydney, NSW Australia.
Malcolm P Caulfield, Heather Cambridge, Susan F Foster, Paul D McGreevy. Vet J 2013 Sept 21 [Epub ahead of print].