1 February 2014

Animal Fibre - Wool : Science

Animal Fibre - Wool : Science NCERT Notes

Wool comes mostly from sheep. It was the first fibre to be spun into yarn, and it provides more warmth than other animal fibres. Apart from sheep, wool also comes from the angora goat, yak, llama, alpaca, and even camels. All these animals have a thick coat of hair or fleece, which keeps them warm. Wool is obtained from this fleece.

Animal Fibre - Wool, NCERT Notes, CTET Notes, CBSE NotesSheep wool is more commonly available in India. In Tibet and Ladakh, yak wool is more common, whereas in Jammu and Kashmir, it is the angora wool. The famous Pashmina shawls come from the soft under-fur of the Kashmiri goat. In South America, the llama and the alpaca are two animals that yield wool.

Selective Breeding
Actually, there are many different breeds of sheep that are reared in different parts of our country to obtain wool. Some breeds of sheep are selectively reared. This means that their parents are chosen for their special characteristics to give birth to them. For example, some sheep are selected because they have soft under-hair. This process is called 'selective breeding'.
The Nali and Lohi breeds are found in Rajasthan and Punjab, the Rampur bushair in Uttar Pradesh and Himachal Pradesh, and the Bakharwal in Jammu and Kashmir. Gujarat breeds the Marwari and Patanwadi sheep. 

Each breed yields wool used for different purposes.
  • Nali breed wool is used to make carpet wool.
  • Patanwadi wool is used for hosiery.
  • Lohi wool is of very good quality, and is used for making clothes.
  • Bakharwal wool is used for shawls.
Sheep are herbivores, and prefer grass and leaves. However, shepherds also feed them mixtures of pulses, corn, jowar, oil cakes and minerals. In winter, they are fed leaves, grain and dry fodder.
  • Shearing is the first step in processing fibre into wool. It is the removal of the fleece of the sheep along with a thin layer of the skin.
  • The next step is to clean the sheared skin and hair. This is done in big tanks to remove the grease, dust and dirt. This is called scouring.
  • The fleece is sorted according to its texture and type
  • Since the fibres are mostly black, brown or white in colour, they can now be dyed in various colours.
  • Once the dyeing process is complete, the fibres are straightened, combed and rolled into yarn.
  • The longer fibres are made into wool for sweaters, while the shorter fibres are spun and woven into woollen cloth.

In our country, many people earn their livelihood from the wool industry. However, the sorter’s job can be dangerous. They can get infected by a bacterium called anthrax, which causes a fatal blood disease called sorter’s disease. When workers face such risk due to their occupation, it is called an occupational hazard. Sheep rearing is a lot of hard work.

With our free PDF notes you can get success in any competitive or entrance exams like CTET,  KVS, NET, CAT, MAT, CMAT, SSC, B.ED, IBPS Recruitment, IAS, CSAT, State Civil Services Exams, UPTET, PSTET, HTET & many more. It also provides NCERT solutions, CBSE, NTSE, Olympiad study material, Indian General Knowledge, English, Hindi, Mathematics, Current affairs, Science, S.ST, model test papers, important Questions and Answers asked in CBSE examinations.