Seasonal patterns of wool growth in Romney sheep selected for high and low staple tenacity

J.L. Woods, A.R. Bray, G.R. Rogers, M.C. Smith

Wool Research Organisation of New Zealand (Inc.), Private Bag 4749, Christchurch, New Zealand

Proceedings of the New Zealand Society of Animal Production. 1995, 55: 42-45

Fifteen ewes with extreme staple tenacity values at hogget shearing in 1991 were selected from each of the AgResearch High and Low Staple Tenacity selection lines. For two years wool was harvested monthly from midside patches and clean wool production, clean wool yield and fibre diameter mean and variation were determined. Staple tenacity, staple length and greasy fleece weight were measured at shearing each November. Clean wool production followed the normal seasonal pattern for Romneys, with summer maxima 3-4 times higher than winter minima. Fibre diameter followed a similar pattern with maximum fibre diameters being 1.3-1.7 times greater than minimum values. Overall, the High Staple Tenacity group had greater staple tenacity (P<0.001), staple length (P<0.01), greasy fleece weight (P<0.05), clean wool production (P<0.05) and fibre diameter (P<0.001) than the Low Staple Tenacity group and lower variability in fibre diameter (P<0.001). Differences between the groups were most pronounced in winter.

Keywords: NZSAPAB; wool production; fibre diameter variability; seasonality; staple strength; Romney

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Last Updated 25-01-1997