08/06/2026
A fortnight ago, the was about goats and how they lack the lanolin that keeps sheep waterproof.
I am sure I will share loads more cool wool facts (also recommend following British Wool for all the best wool info) but today's info is about temperature regulation in sheep.
The second half of May in the UK bought a heatwave - we certainly had a few days over 30⁰ here in Lincolnshire, and it's a shock when it jumped up from 15⁰ the week before! Our shearer aims for anytime from the end of May into mid June to shear the majority of the flock - the ones who only get done once a year - so they weren't done before the heatwave arrived. Poor hot sheep! But not to worry - they are quite well designed after all 😁
🚨 Risks 🚨
* Higher air temperatures (especially if higher than the healthy body of a sheep, around 39⁰C), increased humidity, lower wind speeds and higher night time temperatures all increase the risk of heat stress, just as it does with humans.
* If there's no wind or higher humidity, it's much harder to lose heat through convection.
* If it stays hot overnight as well, the body is under continual stress rather than having the opportunity to cool down overnight.
🐑 Sheep factors 🐑
* Pregnant sheep produce more heat, so struggle more in late pregnancy. None of ours are pregnant so not a concern in our little flock!
* Lambs are more at risk for a number of reasons, including the fact they already 'run hotter' like ewes in late pregnancy do. They also don't have much fleece - which sounds like it would be helpful....keep reading!
* Breeds that evolved in colder regions have adapted features to help them retain heat - such as smaller ears, compact bodies and short legs and necks - are more likely to struggle to lose excess heat when needed, as their bodies are designed for the opposite! Our Herdwick girls and the Scottish primitive gang all fall under this category. The photo below is Foxglove, Herdwick, just after she was sheared last week. You can see how compact she is!
* Fleece length. It seems logical that wearing a 'heavy coat' in the heat must be worse, right? However, wool is so amazing, it actually protects the sheep from external heat (ie on a hot, sunny day) but only if the fleece length is 3-4cm long. Our Valais, who are sheared in early Spring and again in Autumn, were quick to seek shade last week; their fleeces have grown back about 2cm. Cosmos, who is wider than he is tall when he's due for a haircut, was reasonably comfortable. When I pushed my hands right down into his fleece, it was cooler closer to his skin than on the surface which was pretty clever!
❤️ How to help ❤️
* Provide plenty of shady places so that the sheep can choose when to get out of the sun.
* Provide lots of fresh, cool water. Our animals all have plenty of water, but we spread some buckets around a bit more so that they didn't have to walk as far to get a drink during the highest temperatures.
* Minimise the amount of handling / moving them around - ie leave them to chill out!
