Temperatures for 2013 were the hottest on record in Australia. This January we have seen record heat wave conditions across eastern Australia. Individual hot days (over 40 degrees) can be a challenge to cope with. However a heat wave is where we have a run of hot days, and often hot nights.
Heat can be a challenge for livestock as well. Animals with the biggest physical stresses, such as fat animals, lactating cows and calves can find hot conditions extremely challenging.
Cattle lose heat primarily through respiration, as well as transference into the air and through sweating. Animals which have a history of reparatory disease or are suffering from respiratory diseases, often find it more difficult to lose heat and are at risk in hot days.
Providing shade is essential for stock in hot weather. Shade can reduce the heat load on animals by up to 50%. Some evidence suggests there can be as much as a 10 degree drop in temperature in the shade.
When you consider shade, take the time to consider what type of shade is provided. A single tree will never be enough.
Cattle need to have some air flow to allow heat to dissipate into the air around them. If they are packed in close to each other under a single tree, they can't cool down.
Research suggests that in hot weather cattle will choose shade over water, and will access water or grazing at evening time or during the night time.
If there is no shade available, cattle will camp close to water supplies, or even stand in water supplies to keep cool. This causes longer term issues such as poor water quality and dam or bank erosion.
Poor water quality will contribute to lower water intake and reduced production.
As hot conditions are forecast, I reckon its worth considering drafting the at risk stock into management groups where they can be looked after more carefully. For instance cows and calves should have preference to shade, then fat stock and then dry stock. Dark coloured or black animals will find hot conditions more challenging as well, so thought should be given to them.
Its important to try and avoid working with stock during the hot parts of the day, and to plan transport so your stock can travel when its cooler.
With some planning and thought, as well as the practical approach of providing adequate shade and access to good quality water, your stock will manage hot conditions more successfully.