Since I last wrote about waiting for warmer weather, we’ve been treated to some very hot days indeed! The early part of July saw some tremendous temperatures, well into the high twenties, with plenty of glorious sunshine to go with it. I’m not really that keen on it being too hot, especially if I have to work in the heat and dairy cows tend to agree.

A dairy cow suffers from heat stress a lot sooner than we might expect, because digestion creates such a lot of heat; she’s generally producing about 1.2KW of heat, so it’s a bit like walking around with a radiator strapped to her front! This is made worse by things like humidity and direct sunlight.

If conditions are right, she could be suffering the effects of heat stress from as low as 20-22 degrees Celsius. Generally when this happens you’ll see cows panting, their intakes and milk yields will drop and there may even be repercussions in fertility performance too.

When cows are outside, try and make sure they have some shelter to get out of the sun; shaded areas are often significantly cooler. Needless to say, plenty of fresh clean water is also vital, as is the flow rate.

A lot of cows will tend to want to drink at once when you bring them in for milking and the water trough needs to be able to keep up. Remember, if you have any lame cows, this may be the only time they’ve taken the opportunity to drink all day.

If cows are still housed consider having some fans to move the air around and keep the shed cooler, or a method of spraying cool water onto them. I’ve found that a length of pipe with some old sprayer nozzles every few feet works really well.

Strung up above the cows at the feed fence, you’ll find cows standing underneath it every time you turn it on, with the added advantage that they tend to eat a little bit more whilst they’re there.

Adam Collantine

Dairy Consultant

07880 008144

Adam.collantine@dugdalenutrition.com