"Having to shear the sheep for wool is actually very costly and labor intensive.

VOA: special.2009.08.03

It says the price index contained this amount of beef, this amount of sheep wool, this amount of sole leather, and this amount of corn; that was the first consumer price index ever used for financial contracts.

指数中包括这些数量的牛肉,这些数量的羊毛,这些数量的鞋底皮,这些数量的玉米,这是在金融合约里出现的,第一个消费者物价指数

耶鲁公开课 - 金融市场课程节选

In developed countries, microbiologists do these tests with blood from wool sheep or horses.

VOA: special.2009.08.03

It produced the same results as tests using wool sheep and horses.

VOA: special.2009.08.03

Also,hair sheep require less care than wool sheep.

VOA: special.2009.08.03