A review of cashmere fiber phenotypes: Production, heritabilities, and genetic correlations

Cashmere is one of the softest, most expensive animal fibers and is produced from the down hair of goats. Cashmere production originated in Asia but now occurs across the world in countries such as Australia, New Zealand, the United Kingdom, and the United States. The Wool Products Labeling Act of 1939, cashmere goat associations, and textile processors have standards for fiber to qualify as cashmere. One of the main qualifying traits for cashmere is mean fiber diameter, usually finer than 19 µm. Additional fiber traits are important to cashmere producers such as down length, down weight, and down yield. Currently, phenotypic selection is one of the only tools available for cashmere producers in many countries to make improvements to these economically relevant fiber traits because most countries do not currently have a national genetic evaluation for cashmere production. Estimation of variance components and genetic correlations from analyses of cashmere fiber traits is limited in literature. Most published genetic analyses were completed in Australia, New Zealand, and Asian countries. Fiber trait definitions and phenotype collection and measurement highly varied between studies, highlighting the need for more standardization. Heritabilities reported in literature for important fiber traits are moderate to high. An antagonistic genetic correlation may exist between mean fiber diameter and other fiber traits such as down yield, down weight, and down length. Because of these potential antagonisms, producers likely need additional tools, such as a properly weighted selection index, to make informed selection decisions. However, heritabilities and genetic correlations reported in literature are dated and often limited to countries outside of the United States. New research initiatives are necessary to upgrade and enhance the current breeding tools available to producers who strive to improve cashmere production, especially in countries which do not currently have a national evaluation for cashmere traits.