Breed comparisons in combined LAMBPLAN: Genetic group and linkage assessment

In response to changing industry selection practices and a desire for a simpler genetics landscape, Sheep Genetics is developing a Combined LAMBPLAN evaluation that merges the Maternal and Terminal sire analyses. A key challenge, especially when combining multi-breeds for genetic evaluation, is ensuring fair comparisons across diverse genetic backgrounds. To address this, genetic groups have been redefined and assessed for prediction accuracy, and across-flock linkage has been evaluated to determine the degree of connectedness and robustness of prediction across the combined population. Results show that the new genetic groups effectively capture population structure and that strong linkage supports robust across-flock comparisons. These findings provide key evidence for implementing the Combined LAMBPLAN evaluation to improve the accuracy and relevance of Australian Sheep Breeding Values (ASBVs).