UC Davis

Navajo-Churro sheep are sacred to the Navajo people and have a double-coated fleece that weavers shear, card, and spin into yarns to create exquisite, woven Navajo textiles. The only previous Navajo-Churro wool research from 1942 focused on fiber types within a fleece and their effect on textile qualities. Physical characteristics of guard and undercoat fibers were documented, but there is no complete fiber data set for Navajo-Churro wool. A Navajo-Churro fiber survey was created by measuring physical characteristics, including dimensions, colorimetric parameters, tensile properties, morphological features, and surface scale structure of guard hairs and undercoats fibers. In addition, UC Davis Dorset and Hampshire/Suffolk crossbred sheep fibers were measured to compare Navajo-Churro fiber quality to common northern California breeds. Navajo-Churro fleeces display long staples protruding from a bundle of short fibers. Meat breed UC Davis fleeces are a bundle of short fibers crimped together. Guard hairs are thicker and longer (majority 50 – 60 µm, 185 – 274 mm) than undercoat (28.3 – 32.8 µm, 99.2 – 185 mm) and UC Davis fibers (25.9 – 40.1 µm, 41.3 – 123 mm). CIE L*ab color parameters range within all individual fleeces. Variations in modulus, strength, and strain measurements among undercoat (1515 – 1955 MPa, 147 – 188 MPa, 63.8 – 73.5%) and UC Davis fibers (1202 – 2224 MPa, 136 – 202 MPa, 55.8 – 74.7%) are statistically analyzed. Guard hairs have no crimp and polygonal/elongated scale patterns. Undercoat and UC Davis fibers exhibit crimp and patterns of wrap-around and angled scales. This study’s data may be useful to breeders as a standard for Navajo-Churro wool quality parameters. Undercoat and UC Davis fibers are both medium type in fineness, so sheared UC Davis meat breed wool has potential for textile applications, as undercoat fibers are ideal for Navajo weavers’ use.