Relationship between age and postnatal skin follicular development in three types of South American domestic camelids

Abstract

Fifteen alpaca kids, comprising 10 huacaya and 5 suri, and 10 llama kids of chaku type, born on January 1998 at the “Alpaquero” Developing Centre of Toccra, located in the Arequipa Plateau, Caylloma Province (Peru), were chosen for determining the age at which all the secondary follicles reach the maturity, as well as for comparing the skin follicular structure and activity among these different types of Peruvian camelids. Skin biopsies were taken at 2, 4, 6, and 10 months of age in order to monitor four follicular parameters: i) follicular density (FD), ii) ratio of secondary to primary follicles (S/P), iii) percentage of medullated secondary fibres (PMS); and iv) percentage of active secondary follicles (PAS). As a general trend, three parameters, i.e., FD, PMS, and PAS, reached maximum values at the 2 nd month, minimum values at the 6 th month (i.e., during the winter season) and increased again until observations stopped at month 10. A slightly different trend was shown by the S/P parameter which, after having gained its maximum value at month 4, progressively decreased until the end of the observations. It is concluded that the South American camelids here investigated, gained a complete and mature skin follicle apparatus at an early age and, hence, producers should practice an anticipated first shearing.