Do they shed out naturally like a horse or a cow? Is it the same for hair sheep and wool sheep? Is it bad for their health?

All sheep shed, but the wool sheep can´t get rid of their wool on their own, so it accumulates. Some time ago there was footage of a (I think it was a merino) sheep in New Sealand that had roamed free for years. It was incredible, it looked like a walking mountain of wool, not even recognizable as a sheep.

Most hair sheep will shed out; some will keep a "mohawk" down their backs that needs to be shorn clean. Wool sheep should be shorn annually to prevent matting and accumulation of dung and urine in the crotch. Matted wool can lead to skin infections, and dirty wool can lead to fly strike, so yes, it can effect their health.

His name is Shrek

WOW!!!

Thanks, everybody. I googled Shrek and found some interesting pictures. Thought others might like to see them.
[attachment=6604:Shrek_the_Sheep.jpg]

Musterer Daniel Devine carries Shrek, a Merino sheep that evaded shearers for six years in Central Otago. Shrek made international headlines in 2004 when he was finally caught and shorn of his massive 27-kilogram fleece. On high-country stations, where sheep are run on mountains and rugged hills, it is not unusual for some to be missed. When they are mustered the following year, they are known as double-fleecers. It is not unheard of for a sheep to miss three shearings, but to miss six is rare indeed.

[attachment=6605:Shrek_gets_shorn_1.jpg] [attachment=6606:Shrek_gets_shorn_2.jpg]

NEW ZEALAND - APRIL 28: Shrek the 9 year old merino wether has his fleece shorn by former world blade shearing champion Peter Casserly, at the Golden Gate Lodge in Cromwell, New Zealand, Wednesday April 28, 2004. Shrek's fleece is believed to be 6yrs old after the animal was found on the Bendigo Station hilltops during a muster on April 15.
Photo: Ross Land/Getty Images
Apr 28, 2004

Also, sheep with heavier fleeces will overheat more quickly during physical exertion.

And as you can see with Shrek, suffer a severe case of wool blindness (the wool blocks their vision). I'm surprised a predator didn't get him since he certainly couldn't rely on peripheral vision to help him identify potential predators and escape (maybe there are no real predators to speak of in NZ)....

My sheep, who are due to be shorn in two weeks, were panting when the temps reached the 80s, so I wouldn't consider it very humane to leave wool on sheep in warmer climates.

As for shedding, generally if wool sheep are losing wool it's the result of "wool break," which occurs where the wool fiber is weaker for some reason (like a period of illness or poor nutrition; you'll sometimes also so it with ewes who have lambed recently). When I was in Wales I did see wool sheep that appeared to be shedding, but it's not typical.

J.

Maybe they tried, but couldn´t get through....

wow: I bet Shrek felt a lot different after all that wool was gone!! it must have been heavy as heck to carry around!

I bet. 27 kg = about 60 lbs.

This was Rasta Bob. He was a Romney x Coopworth wether I sold, then reclaimed. He hadn't been shorn in three years:



Then, Bob was shorn:



The rest of Bob. I'm 5'4" for scale (granted, I'm sitting down). The fleece was 11" long & weighed nearly 30 Lbs.



Bob has long since been made into sausage. He was plenty fat under all that wool- I don't think he burned a single calorie staying warm over the winter!