Resumo

CORVA, P.M; COLAVITA, M.I; LEGAZ, G  e  MARTINEZ, M. Genealogical and molecular analysis of an Argentinean Angus seedstock herd. BAG, J. basic appl. genet. [online]. 2015, vol.26, n.2, pp.17-28. ISSN 1852-6233.

Introduced in Argentina from the British Isles in 1879, the Angus progressively became the most popular beef cattle breed in the country. In this article the analysis of genealogical and molecular information generated in the registration process of progenies from an Angus seedstock herd is presented. The objectives were to analyze the genetic structure of the herd, and to use the acquired information to get insight of the history of the Angus breed in Argentina. Pedigree information from 16,611 individuals born between 1954 and 2012 was analyzed, including Black and Red Angus. Also available were genotypes of 17 microsatellites from 470 individuals born between 2005 and 2012. Identification of the most influential ancestors showed a trend that is consistent with the evolution of selection objectives, mostly associated with changes in body size. Generation intervals in the male pathways also reflected drastic changes in selection objectives over time. Molecular kinship and genealogical average relatedness have been steadily increasing. Molecular FIS was -0.023, indicating that matings were planned in order to avoid inbreeding, which increased 0.70% per Equivalent Generation. Genetic distance showed that Black and Red Angus are two separated lines within this herd. Molecular and genealogical information jointly allowed for a reliable characterization of the genetic structure of the herd, a strategy that should be extended to the entire breed to monitor genetic variability and to help in breeding decisions.

Palavras-chave : Population structure; Coancestry; Microsatellites; Inbreeding.