The fleece of sheep is covered with yolk
The quality of sheep wool depends on the age and condition of the animal from which the wool is taken and on the climate in which it lives.
The fleece of a healthy sheep is covered by an oily substance called yolk, which consists of wool grease and dried perspiration. It protects the sheep from rain and keeps the fleece from becoming matted. You know this wool grease as lanolin, used in beauty and health products.
Sheep’s wool also contains cholecalciferol, the D3 form of the vitamin D, a vitamin that holds a whole host of health benefits.
The wool from a 6- to 12-month-old sheep is called lamb’s wool. The fleece from a sheep that is 12 to 14 months old is called hog wool. After a sheep has been sheared for the first time, its wool is called wether wool.
In the 17th century, wool fabrics accounted for two-thirds of England’s exports. Today, the leading wool producers are Australia, New Zealand, Argentina and China. There are about 14 million sheep in the United Kingdom. There are 74 million sheep in Australia, a nation of 21 million people. New Zealand is home to 4 million people and 70 million sheep.
There are about 5 million sheep in the United States. Worldwide there are over a billion sheep.