Polymorphism distribution associated with marbling degree in seven beef cattle breeds being present in La Araucanía Region, Chile

Abstract

Selection of breeding stock is a crucial step in any breeding program, therefore the methodology for animal evaluation has evolved rapidly and in recent decades has incorporated the use of molecular markers. Several multinational companies have made available to producers commercial tests based on these technologies, which allow assessing the predisposition of animals to express a specific phenotype. However, some doubts have begun to arise about negative effects of improper use of molecular markers, these are problems associated with inbreeding depression and long-term loss of response to selection. Therefore, the objective of this study was to assess allele and genotype frequencies of 4 polymorphisms associated with marbling in 7 beef cattle breeds being present in La Araucanía Region of Chile. We evaluated leptin, thyroglobulin, DGAT1 and FABP4 genes, which showed different frequency distributions among breeds with higher allele frequency for marbling in Aberdeen Angus breed and a low frequency in Belgian Blue and Hereford breeds. We conclude that it is feasible to use these tools in genetic programs, but it is also necessary to have reliable genealogical records and advice of professional or technical institutions that can integrate genotypic information from molecular markers in prediction models used for selection of breeding stock.