Why Don’t Sheep Shrink In The Rain? - Raising The Baa

Why Don’t Sheep Shrink In The Rain?

With the British summer as it has been, the sheep are spending more time wet than dry, so why is it they don’t shrink like our woollen jumpers?

When the wool fibres are looked at under a microscope they are covered in fish-like scales. This gives the wool its warmth but it is also why wool becomes felted when washed. The scales open up and act like a one way ratchet, getting smaller every time. Hence the need to dry woollen garments flat, to keep their shape and not to stretch them. So now you know!

There are other reasons why the sheep’s fleece remains in good condition, despite the wet weather…

Firstly nutrition. Just like our skin, hair and nails, nutrition plays a key role in appearance of the fleece. With the grass growing well, sheep produce the natural oil lanolin which keeps the wool from tangling. At lambing time nutrients from the grass are also needed to produce milk, so the sheep’s production of lanolin declines (being less important than the milk) so the wool can become felted. Once the lambs are weaned, the ewe will resume production of lanolin and once sheared, the fluffier fleece will return.

Another reason why the rain doesn’t create a woolly wet mass on the sheep’s back is the way that they fend off the showers. Like a dog, it will shake so the water does not get onto their skin. Shaking is the ovine (and canine) equivalent of a spin-dry cycle! So the wool keeps the rain off their back – as well as the sun (if there is any).

You may notice, if it’s wet and windy, sheep will stand with their back to the wind and will drop their faces down. Let’s face it who likes the wet in their face when looking for predators?

The more hardy breeds will go and find shelter under a tree or behind a wall, but often they would rather stay together than being isolated. Being part of the flock is the safe place to be – it’s their comfort zone if you like.

The one thing a sheep will not do is groom itself like a dog or cat. In fact it’s not even bothered it if it gets shorn or not. So the word vanity will definitely not be found in a sheep’s dictionary!