Growth performance of station tested rams in Slovenia

Abstract

In Slovenian sheep breeding programme rams from top flocks are selected for performance test on growth in two test stations with different conditions. The aim of this work was to develop a model that could be used for genetic evaluation using BLUP method. Data on 3,500 rams of several breeds were collected from breeding programme database and analysed with linear mixed model. The selected model accounted for the following fixed effects: breed, station, age at weighing as quadratic polynomial nested within breed and station, parity and the number of liveborn littermates. Additionally, several random effects were included: origin, origin-year interaction, season as day of weighing, and the effect of individual ram. Results showed differences in growth between breeds and stations, higher body weight for rams born as single lambs and lower body weight for rams born in first parity. Variance component ratios are reported for random effects. The analysis did not include pedigree information, but it was shown a considerable variance between rams.