Inbreeding and its Effect on Performance Traits in Austrian Meat Sheep

Sa？etak The aim of this study was to evaluate the level of inbreeding of meat performance tested herd book sheep in Austria and to evaluate the effect of individual inbreeding on growth and CT (computer tomography) scan carcass traits. Performance data (13,614 records, five breeds: Merinoland, Suff olk, Texel, German Blackheaded Meat sheep, Jura) were collected in the years 2000-2010. The traits analysed were live weight and average daily gain, as well as traits of body frame, back fat and eye muscle area, all measured on live animals with CT. Inbreeding coefficients (F) were calculated with the soft ware PEDIG. F was nested within breed and tested in a mixed model using ASReml. Levels of inbreeding were low with O F of 1.5-3.1%. Only few traits were significantly affected by inbreeding. Both positive and negative effects were found. The effects were small, most oft en nonlinear and vary across breeds. Inbreeding and its effects on performance traits do not seem to be an issue in Austrian meat sheep populations at the moment. However, monitoring and further analyses are recommended