The second tier of Combined LAMBPLAN is due to be released for the 15th of December 2025 analysis run and will include breeding values for worm egg count (WEC).
There are four enhancements made for the WEC module for Combined LAMBPLAN:
Hogget WEC data makes up less than 5% of the WEC data in the LAMBPLAN analyses, with recording of Hogget WEC declining over time. The Combined LAMBPLAN analysis will not use Hogget WEC data, which will also increase computational time for the analysis. The Combined LAMBPLAN analysis will report weaning, post weaning, and yearling WEC.
In the Terminal and Maternal analyses, WEC data is adjusted within a contemporary group to account for differences in variation across groups of animals from different environments, management practices, etc. (known as heterogeneous variance (HV)). This was reviewed for Combined LAMBPLAN and found there was no significant benefit on predicting ASBVs following HV adjustment, so will not be applied in Combined LAMBPLAN.
Genetic parameters are used within the evaluation to account our understanding of the underlying genetic factors influencing how an animal performs. The WEC genetic parameters were reviewed for Combined LAMBPLAN to reflect the larger dataset used and remain similar to those used in the current Terminal and Maternal analyses. There were no significant differences in genetic parameter estimates within breeds in the Combined LAMBLAN analysis, so a universal set of genetic parameters will be applied. Maternal effects will be used for both weaning and post weaning WEC in Combined LAMBPLAN.
Genetic groups are used in the Sheep Genetics evaluations to help describe breed and population structure of animals with missing pedigree. The genetic groups in Combined LAMBPLAN will be at a genomic breed structure level (were previously at a flock level).