With temperatures set to get close to or over 30°C later this week and be over 25°C for five days or more, farmers should prepare for the hot weather.

The first thing to make sure is that there is sufficient water for cows to drink. Slow-filling water troughs are a big issue on some farms and will lead to increased stress in cows if they can’t get enough water to drink.

Water intake per cow almost doubles during warm weather, so if the water system is under pressure during normal weather, it’ll be under twice as much pressure during a heatwave.

Heat stress is unlikely to be a problem on most farms, but it could be an issue on some, particularly where cows are housed for all or part of the day.

Heat stress

Moderate heat stress is likely when temperatures go above 24°C, with more severe heat stress when temperatures go above 26°C.

Essentially, heat stress is when the cow needs to work harder to cool down. The hotter the temperature, the harder she needs to work and the more energy she will have to partition to cooling off rather than production.

Ambient temperature in a shed with poor ventilation could be a few degrees higher than the outside temperature, so farmers running a confinement system need to be particularly careful to watch for signs of heat stress.

In an ideal situation, cows would be grazing fields with good shade during the day, although this is not always possible.

With no rain in the forecast, it’s highly likely that most farms in the south, east and midlands will be in a grass growth restricting soil moisture deficit position shortly, if they aren’t already.

Having to put in extra feed will be inevitable and, indeed, many farms are already supplementing heavily.

We will probably begin to see grass starting to wilt later this week (it’s already wilting on some farms).

I would be slow to put in too much feed when grass is wilting, as it’s better to utilise the grass before it wilts away.

Play it by ear and adjust accordingly based on conditions on the farm. Most farms are carrying extra grass and are in a good position.

Finally, make sure to protect yourself and others from the sun. Cover your skin as much as possible and wear sunscreen.

Skin cancer is the most common form of cancer in Ireland.