With heatwave conditions set in across the UK it is important that farmers keep an eye on their livestock for signs of heat stress.

Heat stress occurs when an animal’s heat load is greater than its capacity to lose heat.

This is seen prominently in heavy cattle, which cannot handle heat stress compared to lighter weight cattle.

Also at a higher risk of heat stress are pregnant animals, animals recovering from illness, pigs and high-producing dairy cows.

The most visible signs in farm animals tend to be elevated breathing rates, however, increased water intake and sweating, along with decreased feed intake, are other symptoms.

To help prevent heat stress occurring, farmers must pay particular attention to water, feed, shade and management.

Consumption of water is the quickest method for animals to reduce their core body temperature.

For detecting signs of heat stress in your dairy herd, further symptoms include decreased milk production and a change in milk composition (milk fat and protein percentages drop).

Farmers should also pay attention to their livestock crowding, breathing heavily, and standing next to a water trough.

water on dairy farms

On a hot day, cows can drink anywhere up to 110L/day and they can typically drink at a rate of 14L/minute from a trough.

With this in mind, farmers are encouraged to carefully consider trough location, as cattle don’t like to walk more than 250m to get a drink.

Offering feed with a high fibre content can increase the heat of fermentation in the rumen, thus increasing the heat load of livestock.

Cattle should be given preferential access to paddocks with shade from trees and tall hedges during periods of hot weather.

This may mean having to graze more shaded parts of the farm during the day and more open areas during the evening/night.

If moving or handling cattle, farmers should minimise the time cattle are in holding yards and to reduce handling stress.

Where cattle do become affected by heat stress, it’s advisable to isolate the most severely affected animals and provide shade and cooling.

Farmers should avoid handling sheep where possible during hot weather, and where necessary, delay handling or moving sheep until late evening when temperatures cool.

For farmers transporting sheep in trailers, they should ensure there is adequate ventilation and that they are stocked appropriately.

They should check stock regularly during longer journeys and delay movements until late evening/night time where possible.

Farmers with sheepdogs should also be aware that the dogs are susceptible to heat stress, and should delay work until late evening, where possible, provide sufficient rest periods and have access to water.

For outdoor pigs, they will require access to a wallow to cool down, especially if the temperature is above 25°, as these animals are particularly vulnerable to heat stress.

For indoor pigs and poultry the temperature in the animal accommodation must be monitored closely and ventilation adjusted accordingly. 

It is also recommended to reduce stocking densities where necessary to increase air space and flow and to reduce the heat generated by the animals themselves.  

It is also important that farmers look after themselves in the hot weather, by staying hydrated and protecting their skin from the sun with sunscreen and protective clothing.