Observations on the follicle population of Blackface Sheep

摘要: The follicle population of the Blackface breed (‘double-coated’) was followed in skin samples taken from four lambs at eight intervals between 3 days and 43 weeks age. differs greatly that Romney Leicester breeds previously studied (Burns, 1949). 1. At 1 month old secondary/primary ratio ( S/P ) slightly lower than much Romney, difference became accentuated with 2. Fewer secondary follicles are developed after birth or although period during which they can be is longer, extending least to 12 possibly 17 birth. 3. density less half Leicester, but not sufficiently large account for this, mainly due having a primary 4. possibility suggested arise as result ‘induction’ by ‘follicle organizer’ coming quantity decreases advancing It may when high areas affected organizer each overlap, providing sufficient permit numerous developing late post-natal stage, reported Merino. 5. contrast other its conspicuously larger largest follicles. All fibres medullated except about shed, many free medulla. Kemps produced only follicles, some however produce long ‘hair’ fibres. 6. Many grow strongly summer change production non-medullated winter. shedding kemps spring should probably looked upon physiologically an autumn moult, since cease growth ‘brushes’ autumn.