Abstract

Recent interest in sheep requiring less on-farm fleece management has lead to the development of sheep with long wool covering the trunk, but only short wool on the belly and breech. We have characterised developmental and structural features of the skin, including follicle density, primary to secondary follicle ratio and follicle activity state at various body sites of bare- and woolly-bellied ewes, and their foetuses. At 70 days of gestation, foetuses of bare-bellied ewes had developed fewer follicles than woolly-bellied sheep (1.7 ± 0.27 versus 2.8 ± 0.21 follicles per mm2; P<0.01). In adults, similar densities and ratios of primary to secondary follicles occurred in bare- and woolly-bellied ewes in each body site studied including dorsal, midside, anterior and posterior fleece positions, as well as the belly, breech and face. However, the proportion of inactive follicles in late autumn was greater in bare-belly adult ewes, not only on the belly (15.5 ± 1.9% versus 4.9 ± 2.9%; P<0.05), but also across the fleece which exhibited anterior-posterior and dorsal-ventral gradients in follicle activity. The short wool phenotype was thus associated with altered follicle cycles, but no differences in adult follicle densities. However, wool production might be compromised, as follicle activity varied across the whole fleece of bare-belly sheep.

AJ, Craven, DR Scobie, MG Ashby, and AJ Nixon

Proceedings of the New Zealand Society of Animal Production, Volume 68, Brisbane, Australia, 49-52, 2008