Media Release
20 January 2011
Monitoring stock is a ‘heated’ issue, says NZVA
Despite the recent cyclone bringing much needed rain to many parts of the country, some regions are still suffering from
extreme droughts. As the predicted long hot summer continues, veterinarians are reminding farmers to provide adequate
shelter and water for their stock.
New Zealand Veterinary Association animal welfare coordinator, Dr Virginia Williams, says while New Zealand farmers
don’t usually have to face extreme hot temperatures, our increased levels of solar radiation means stock can quickly
overheat.
“Farmers should monitor the behaviour of their animals. The first sign of heat distress is clustering around the water
trough or in groups, trying to get shade from each other.”
Additional signs for cows include decreased production levels, drooling, panting, irritability and in some cases
sub-clinical rumen acidosis. Heat stress can lead to drops in rumen pH, which means some feeds can be unsuitable unless
they are balanced with a fibre source.
Dr Williams says increased respiration is an accurate indicator.
“If respiration rates are getting above one breath per second you need to start mitigating heat distress.”
"Planning grazing, by using shaded paddocks during the day and non-shaded at night, helps stock stay cool during the day
and also warmer during nights," she says.
In addition, Dr Williams also recommends farmers keep cows close to the dairy shed to shorten the walking distance to
afternoon milking.
“Farmers can install sprinklers in the dairy shed as the cows enter to compensate for the additional heat from walking
to the dairy, which can increase the body’s temperature by one degree.”
Cows should be wet to the point where water is running off them otherwise local humidity around the cow increases and
they can become more uncomfortable.
Furthermore, ensure cows are not jammed into the yard tightly without cooling them. Once cows are cooled at milking they
are more likely to graze effectively afterwards, Dr Williams says.
Stock will try and do their bit to stay cool by standing in the shade throughout the day and then grazing at night.
“I think most farmers appreciate the fact their stock gets hot, but it’s important to monitor their condition over the
peak-heat months.”
ENDS