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Trejo 323 -X5000IYG Cordoba -Argentina; 3 European Association of Animal Production -Via G. Tomassetti 3,1/A -00161 Roma -Italia; 4 ILO Universidad de Camerino -Piazza Cavour 19F -62032 Camerino -Italia ResumenLa raza representa un concepto central de la zootecnia y se usa para definir cualquier subdivisión dentro de una especie doméstica. En este trabajo se analiza el nacimiento y la evolución del concepto de raza a lo largo del tiempo y el impacto de la ciencia originada en su entorno. Se discuten los efectos de la domesticación desde un punto de vista genético y se clasifican las razas como: mendelianas, primarias, secundarias y sintéticas. Se analiza el concepto dentro de los camélidos domésticos y se llega a la conclusión que solo existen razas primarias. Se aclaran también conceptos desvirtuados sobre la alpaca Suri, las llamas-alpacas blancas y el concepto de pureza. Se concluye finalmente que se debería seguir el esfuerzo de empresas privadas y organizaciones publicas y privadas para organizar y establecer acciones de seleccion por llegar a la creación de razas estandarizadas.Palabras clave: llamas, alpacas, razas, domesticación SummaryBreed performs a central concept for animal science. It is used to define subdivisions of domestic species. This work analyses the evolution through time of breed concept, and the impact of science on breed evolution. Domestication effects are discussed from genetic point of view and breeds were classified as: primary, secondary, synthetic or mendelian. The concept was analysed within South American domestic camelids in which only primary breeds exist. Misleading concepts on Suri alpacas, white coated llamas-alpacas and pure breeds were also clarified. It was finally concluded that some private enterprise, NGO's and public organisations must follow the practical steps of selection to maintain the breed standards of llamas and alpacas.

Llama, the most numerous domestic camelid in Argentina, has good fiber-production ability. Although a few genes related to other productive traits have been characterized, the molecular genetic basis of fiber growth control in camelids is still poorly understood. Fibroblast growth factor 5 (FGF5) is a secreted signaling protein that controls hair growth in humans and other mammals. Mutations in the FGF5 gene have been associated with long-hair phenotypes in several species. Here, we sequenced the llama FGF5 gene, which consists of three exons encoding 813 bp. cDNA analysis from hair follicles revealed the expression of two FGF5 alternative spliced transcripts, in one of which exon 2 is absent. DNA variation analysis showed four polymorphisms in the coding region: a synonymous SNP (c.210A>G), a single base deletion (c.348delA), a 12-bp insertion (c.351_352insCATATAACATAG) and a non-sense mutation (c.499C>T). The deletion was always found together with the insertion forming a haplotype and producing a putative truncated protein of 123 amino acids. The c.499C>T mutation also leads to a premature stop codon at position 168. In both cases, critical functional domains of FGF5, including one heparin binding site, are lost. All animals analyzed were homozygous for one of the deleterious mutations or compound heterozygous for both (i.e. c.348delA, c.351_352insCATATAACATAG/c.499T). Sequencing of guanaco samples showed that the FGF5 gene encodes a full-length 270-amino acid protein. These results suggest that FGF5 is likely functional in short-haired wild species and non-functional in the domestic fiber-producing species, the llama.

The Llama fleece types, subjectively defined as styles, are described objectively through different types of fibres, which differentiate each other in length, thickness, type of waves, and presenceabsence of lustre. Repeatability of styles and fleece types objectively defined is high. Fleece types can be redefined as double coated and single coated; lustre and hemilustre; intermediate coated as intermediate between lustre and single coated; and intermediate between single coated and double coated, respectively. The differentiation is carried out among the most representative types of fibres of each fleece type considering that the frequency of these fibre types does not influence greatly in the differentiation.

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