Heat stress
Heat stress is most marked when it comes in short bursts with no time for the cow to adapt to the rising temperatures.
When heat stressed:
- A cows’ feed intake milk yield decline. Intakes can decline by 10-30%. Milk yield can decline by as much as 20%.
- There will also be a reduction in fertility, including an increase in embryonic loss.
- There is also evidence of an increase in the risk of clinical mastitis.
Minimise the effects of heat stress on animals
Water
- Provision of clean drinking water is critical for all animals during hot weather
- As temperatures rise, cows will drink up to 30% more water (in excess of 100 litres/day)
- As they will need water more often, it is important that cows are not forced to walk long distances for water
- If possible, make water available to cows before and/or after milking so that cows have their needs met
Shade from direct sunlight
- Provide shade areas to allow cows to keep cool away from direct sunlight
- Where possible, use paddocks with trees for shade or allow access to housed areas during the day
- Reduce the time cows spend in holding yards to a minimum
- Watch for sunburn, especially in white coloured cows, and keep these cows indoors day and night if required
