development of wool

development of wool

• 1.
  CLASS PRESENTATION ON DEVELOPMETOF WOOL Suggested by-Dr. S. K. Bharti Presented by- Yash Kumar Awasthi DEPARTMENT OF LIVESTOCK PRODUCTS TECHNOLOGY COLLEGE OF VETERINARY SCIENCE & ANIMAL HUSBANDRY UTTAR PRADESH PANDIT DEEN DAYAL UPADHYAYA PASHU CHIKITSA VIGYAN VISHWAVIDYALAYA EVAM GO ANUSANDHAN SANSTHAN MATHURA
• 2.
  Development of woolfollicle / fibre  Mature fleece is produced by wool follicle  Basal layer of the epidermis crucial in wool follicle formation  Follicles appear in the second month of gestation Epidermis Basal layer Dermis
• 3.
  Different stages inwool development
• 4.
  Development of Wool Basal layerthickens and Grows down into the dermis Forms a plug of cell tissues . The plug forms the wool follicle and accessory structures Plug further moves downwards Two out-growths appear on the same side; sebaceous and sudoriferous glands Lower end of bulb becomes bulbous Base of bulb turns inwards and forms dome like structure containing actively dividing cells, this is called papilla. Cells in the papilla divide and elongate to form wool fibre and the inner root sheath
• 5.
  Development of Wool  Follicleshave shape of a golf club because the papilla is derived towards the side of the follicles  Orientation of the papilla and shape of the follicle are connected to the crimpiness and waviness of the fibre  In a mature follicle the bulb region proliferates and organises to the Outer Root Sheath and Inner Root Sheath  The ORS forms the cuticle of the fibre whereas the IRS forms the cortex of the fibre
• 6.
  Follicles in theunborn are arranged in a group of 3 Follicles forming the trio are primary follicles Each trio is associated with accessory structure sebaceous gland, sweat gland and arrector muscle Sweat glands(suderiferous gland) apocrine type Sweat gland secretions suint Sebaceous gland wool wax Yolk suint + wool wax Follicular Arrangement on the Skin
• 7.
  Mature Primary WoolFollicle
• 8.
  . Primary follicles producecoarse fibres whereas Secondary follicles produce fine (merino type) fibres Arrector muscle – Attachment Lower end Follicle Upper end Basal layer
• 9.
  *New follicles calledsecondary follicles appear in association with primary follicles *Secondary follicles are present on the upper side of the primary follicle and lack arrector muscles. * Sebaceous glands associated with secondary follicles are smaller than those associated with primary follicles. * The S:P ratio i.e. Secondary: Primary dictates types of fleece produced. Follicular Arrangement on the Skin
• 10.
  Thank You