Evaluation of fiber medullation of Suri alpacas (Vicugna pacos)

Olarte C.U.D.; Ormachea E.V.; Calsin B.C.; Quispe E.P. · Revista de Investigaciones Veterinarias del Peru (2025) · DOI: 10.15381/rivep.v36i3.30919

Resumen

The study aimed to evaluate the percentage and mean diameter of fibres according to the type of medullation in alpacas, as well as to determine the existence of variations due to sex and number of shearings. The study included 108 Suri alpacas, obtaining 6 g of fibre sample from the middle rib region of each animal (30 males and 78 females) and registering thenumber of shearing (I =1st, II = 2nd, III = 3rd, IV = 4th, V = 5th and VI = 6th shearing or more) corresponding to one year of fibre growth. The dependent variables were type of medullation (non-medullated, with fragmented medullation, continuous, discontinuous and heavily medullated) and their corresponding mean diameters. The fibres were analysed with the Fiber Med equipment. The nonparametric Kruskal Wallis test and the comparison of pairs of ranks by the Dunn method (α=0.05) were used, as well as the Spearman’s correlation to evaluate the relationship between the dependent variables. The results indicate a high fibre medullation rate of over 60%, with fibres with continuous and fragmented medullation being the most abundant. The incidence of heavily medullated fibres is above 1%. Sex has no effect on the incidence of any fibre type according to medullation or their respective AFD, except for fibres with continuous and fragmented medullation. Males have lower FMF and CMF. Higher shearing frequencies increase the percentage of medullated fibres and fibres with continuous medullation, but the AFD of fibres with different types of medullation also increases. The phenotypic correlation is high and positive between the mean fibre diameter and the percentages of fibres with fragmented, discontinuous, and continuous medullation, although it is lower with the percentage of heavily medullated fibres. © Los autores. Este artículo es publicado por la Rev Inv Vet Perú de la Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos. Este es un artículo de acceso abierto, distribuido bajo los términos de la licencia Creative Commons Atribución 4.0 Internacional (CC BY 4.0) [https://creativecommons.org/licenses/by/4.0/deed.es] que permite el uso, distribución y reproducción en cualquier medio, siempre que la obra original sea debidamente citada de su fuente original

Instituciones: Universidad Nacional Agraria La Molina; Universidad Nacional del Altiplano