Derivation of economic values for fibre diameter fleece weight in alpacas

Abstract

Economic values for fibre diameter and fleece weight in alpacas were derived using profit equations. Parameters in the profit equation were chosen to reflect the production and commercialisation of alpaca fibre in Huancavelica (Peru). Income depends on the weight and colour of fleeces commercialised from each of the four different categories defined by the technical Peruvian normative: Extra fine (EF), Fine (F), Semi Fine (SF) and Coarse (C). Basically, the four categories are determined by the amount of fibre in the whole fleece finer than 26.5 μm (>70%, 69-55%, 55-40%, <40%, respectively). The selection criteria to improve the quality and quantity of fibre produced are respectively the fibre diameter in the mid-side site (DF) of alpacas and the greasy fleece weight (PV). DF was assumed as an underlying continuous variable and threshold values for the four quality categories (EF, F, SF and C) were approximated using the relationship between DF and the fibre diameter in the whole fleece. Economic weights were derived by first derivatives of profit equation with respect DF and PV considering costs uncorrelated with both parameters. The prices paid in the region of Huancavelica for the different categories and colours (white, cream, other colours) in the period 2005–2009 were considered to obtain economic values and to analyse the effect of changes in fibre price. Economic values were greater for PV than for DF, and greater for white and cream alpacas than for alpacas with other colours. Sensitivity analysis of economic values to changes in price showed that they vary considerably, and also the ratio of economic values varies for DF and PV. The DF seems to be economically more important when prices paid to producers are lower. Nevertheless, results should not be applied in breeding programmes without other analyses being performed using other participatory approaches.