Abstract:
Proc. Aust. Soc. Anim. Prod. I996 Vol. 21 THE EFFECT OF NUTRITION ON SKIN THICKNESS OF FINE AND BROAD WOOL MERINO SHEEP P.J. MURRAY Dept of Animal Production, The University of Queensland, Gatton, Qld 4343 Gregory (1982) and Williams and Thomberry (1992) observed positive genetic correlations between skin thickness and clean fleece weight. Lyne (1964) found changes in skin thickness followed changes in body weight. A positive relationship between feed intake and skin thickness is not always the norm. Williams and Thomberry (1992) found that grazing Fleece Plus sheep had thicker skin than Fleece Minus sheep and this was not related to the liveweight of the 2 groups. However, when individual sheep from both groups were pen-fed, there were no differences in skin thickness or liveweight between groups fed high or low levels of intake. The aim of the experiment was to determine the influence which feed intake has on skin thickness of fine and broad wool sheep within Peppin and Bungaree strains. The mean fibre diameter, liveweight and skin thickness of sheep in the fine and broad wool sheep groups, within each strain, at the start of the experiment, are given in Table 1. The sheep (12 per group) were individually fed a pelleted ration at 1.5% or 2.2% of individual liveweights or ad libitum for the 8 week long experiment. Measurements of the thickness of clipped midside skin were taken using a set of Harpenden skin calipers at the start and end of the experiment. Table 1. Mean fibre diameter (pm), liveweight (kg) and skin thickness (mm) for broad and fine wool groups within strains at the start of the experiment Table 2. Mean fibre diameter of the wool snippets (pm) and skin thickness (mm) for broad and fine wool sheep from Bungaree and Peppin strains measured after 8 weeks at 3 levels of feeding GREGORY, I.P. (1982). Aust. J. Agric. Res. 33: 363-73. LYNE, A.G. (1964). Aust. J. Agric. Res. 15: 788-801. WILLIAMS, A.J. and THORNBERRY, K.J. (1992). Proc. Aust. Sot. Anim. Prod. 19: 138-41. 388