Hair follicle group and skin follicle population of some non-Merino breeds of sheep

Abstract

Skin specimens from 494 ewes were collected in flock samples of 11-23 animals, mostly 8-18 months old, from Australian and overseas sources among the following breeds: Corriedale, Polwarth, Lincoln, English Leicester, Border Leicester, Romney Marsh, Southdown, Dorset Horn, Suffolk, Ryeland, Scottish Blackface, Welsh Mountain, Swaledale, Cheviot, Wiltshire, and Swedish Landrace. The specimens were taken by a standard biopsy method and evaluated in the manner described by Carter and Clarke (1956). For each flock sample the mean, standard error, and range of individual values were recorded for the following estimates : total (np+s) follicle population density; primary (np) follicle population density; ns/np, ratio; primary fibre diameter (dp); secondary fibre diameter (2,) ; fibre diameter of the composite population (dp+s) ; of primary and secondary fibre diameters (dp/ds) . The data supplement those recorded for the Australian Merino sheep (Carter and Clarke 1957), and demonstrate the small hair follicle groups apparently characteristic of most British short-, long-, and carpet-wool breeds in well-marked contrast to the large groups in the skin follicle population of the Australian Merino. This difference between the Merino and other breeds may be general except where new breeds have developed from crossing with the Merino or its derivatives, when hair follicle groups of intermediate size may be found as in the Corriedale and Polwarth.