Recessive mutation for low fibre curvature in the wool of sheep

• Published in: Small ruminant research 2023-04, Vol.221, p.106934, Article 106934
• Main Authors: Scobie, D.R., Richena, M., van Koten, C., Plowman, J.E., Lloyd, H., Harland, D.P.
• Format: Article
• Language: English
• Subjects: Bulk; ewes; Fibre curvature; fleece; Lustre; males; mutation; progeny; recessive genes; sires; Suffolk (sheep breed); wool; yearlings
• ISSN: 0921-4488
• DOI: 10.1016/j.smallrumres.2023.106934

Two mating experiments suggest a recessive gene for lustre in the birth coat of the lamb and low fibre curvature of the yearling fleece. Suffolk sheep normally have high wool fibre curvature, but a sire was found that had very low fibre curvature (21.0°/mm). In the first experiment, no lambs were born with a lustrous birth coat among the initial progeny from this sire (n = 32). Fleece samples at weaning (70.0°/mm) and yearling shearing (67.6°/mm) had high fibre curvature with no sign of segregation. All second-generation progeny of this sire (n = 4) were born with a lustrous birth coat, yet none survived to lamb shearing. Breeding was discontinued. In a second experiment, two male lambs were born with lustrous birth coats and low fibre curvature at weaning (29.0°/mm, 20.8°/mm). First generation progeny (n = 17, n = 18) from these sires showed no evidence of lustre of their birth coat, with fleece samples that were relatively high in fibre curvature at weaning (43.1°/mm, 43.8°/mm) and yearling (43.4°/mm, 45.4°/mm) respectively. When one sire was crossed back to the ewe progeny of both (n = 10) there was strong evidence for segregation of lustre of the birth coat. Lustrous lambs (n = 9) had low fibre curvature when shorn at weaning (21.0°/mm) in comparison with lambs (n = 8) with a wild-type birth coat (46.5°/mm) (P