CHARACTERISTICS OF MEDULLATED FIBERS IN PERUVIAN HUACAYA AND SURI ALPACA

Abstract

The presence of objectionable medullated fibers, which are almost all strongly medullated and, particularly, continuously medullated fibers, negatively affects the attractiveness and quality of alpaca yarns and garments. However, medullated fibers facilitate thermoregulation (heat retention) in the animal, while garments are lightweight due to the low specific weight of the fibers. There is scarce information about the incidence of fibers according to their type of medullation in alpaca fleeces. The objective of this research was to evaluate the influence of location, age and sex of the Huacaya and Suri alpaca on the characteristics of medullated fibers. For this, 396 fiber samples were taken from the mid-side area of Huacaya (329) and Suri (67) alpacas. Types of medullated fibers were evaluated using the FIBER MED instrument, obtaining the percentage of medullated fibers (MED, %) and the average fiber diameter (MFD, µm) of each type. The results indicate that these characteristics of medullated fibers are greatly influenced by location and age in Huacaya alpacas. Conversely, place and age have little influence on the types of MED and MFD in Suri alpacas, with higher percentage of total medullation and percentage of fragmented medullated fibers in females with respect to males. In conclusion, when compared to Suri, Huacaya alpaca shows a high variability in the percentage and diameter of types of medullated fibers (fragmented, discontinuous, continuous and strongly medullated), depending on the location, age and sex of the animal.