Fleece tenderness: the effect of nutrition, age and lambing status on pregnant Romney and Coopworth mixed-age ewes

J.M. Fitzgerald, D.C. Smeaton and K.T. Jagusch

Whatawhata Hill Country Research Centre, Ministry of Agriculture and Fisheries, Hamilton and Ruakura Animal Research Station, Ministry of Agriculture and Fisheries, Hamilton

Proceedings of the New Zealand Society of Animal Production. 1984, 44: 53-56

Mid-pregnancy feeding levels produced significant differences in staple strength (37 v 20 newtons/kilotex in the Romney; and 52 v 45 N/ktex in the Coopworth) and diameter at the point of break (37 v 34 µm in the Romney, and 39 v 36 µm in the Coopworth) for high and low nutrition treatments respectively. Subsequent late pregnancy and post-partum nutrition treatments did not generate staple strength differences.

Despite a high correlation (r=0.95) between position of break and minimum fibre diameter, less than 30 percent of the variation in staple strength within each flock could be accounted for by the variation in fibre diameter at the point of break.

Keywords: NZSAPAB; Fleece tenderness; staple strength; fibre diameter; mid- pregnancy nutrition