Navajo-Churro Wool Fiber Survey with References to California Mutton Breeds

Abstract

Five fleeces representing the range of appearances and colors of 17 registered Navajo-Churro sheep as well as seven fleeces from Dorset, Hampshire, and Suffolk mutton/lamb breeds were surveyed for their colors, fiber dimensions, surface structures, and tensile properties. The double-coated Navajo-Churro fleece consists, in majority, of fine and short undercoat fibers (28.3–32.8 µm wide, 99.2–185 mm long) with slight crimp and contains few much coarser, longer, straight, and medullated guard hairs (50–60 µm wide, 185–274 mm long). Mutton/lamb fibers ranged from 25.9 to 40.1 µm in diameter and from 41 to 123 mm in lengths, mostly wider and shorter than the Navajo-Churro undercoat fibers, both from 6 months of growth. The Navajo-Churro undercoat fibers exhibit slight crimp and wrap-around and angled scale patterns, as do mutton/lamb breed fibers, but their guard hairs have polygonal/elongated scale patterns and no crimp. The Navajo-Churro undercoat fibers had similar tensile strength (147–188 MPa) and strain (63.8–73.5%) values as mutton/lamb fibers (136–202 MPa, 55.8–74.7%), but their modulus values fell into a narrower range (1515–1955 MPa vs 1202–2224 MPa). This first fiber survey serves to document key fiber attributes of culturally significant Navajo-Churro and mutton/lamb breeds for quality assessments, breeding, product design, and developing potential applications for under-utilized by-product wool.

Keywords

• Navajo-Churro
• mutton breeds
• fiber diameter
• fiber length
• tensile properties
• color & scale