The value of research and industry flocks for predicting breech strike resistance in Australian Merino sheep

This study used data from the Sheep CRC Information Nucleus Flock (INF), a Merino Lifetime Productivity (MLP) flock, and a ram breeding flock (Connemara) to evaluate the prediction of breeding values for breech strike between and within datasets. Cross-validation was used to evaluate the accuracy, predictability and dispersion of estimated breeding values. Validation between datasets had low predictability due to low linkage (pedigree-based) across flocks, but validation within datasets was encouraging. Considering the poor linkage between the three datasets and the low incidence of breech strike across flocks, the industry needs to continue investing in building and maintaining suitable sheep reference populations with a wide range of traits, including flystrike observations, to develop accurate predictions required to underpin direct and indirect selection. In addition, quantifying the value of genomic information to improve the accuracy of predictions will be the subject of ongoing research.