Index breeding values for the Combined LAMBPLAN analysis will be released in July 2026.
There are three key enhancements made for the selection index module for Combined LAMBPLAN:
1. Current Terminal and Maternal indexes will remain
The current Terminal and Maternal indexes have been retained for the initial Combined LAMBPLAN release because they are well understood by industry, reduce unnecessary re-ranking during the transition, and allow sufficient time for future review of index structures. This approach also helps users distinguish changes resulting from Combined LAMBPLAN analysis enhancements from any future index redesign
This means that we will produce Terminal Carcase Plus (TCP), Lamb Eating Quality (LEQ), Eating Quality (EQ), Maternal Carcase Production (MCP), Maternal Carcase Production Plus (MCP+), Maternal Wool Production Plus (MWP+), and the Border Leicester Cross (BLX). Under Combined LAMBPLAN, all seven existing indexes will be calculated for all eligible animals regardless of breed, subject to the existing index reporting thresholds and accuracy requirements.
2. Review of the selection advantages for Combined LAMBPLAN indexes
The selection advantage (the difference in genetic merit between the top 10% of animals and the average population) was reviewed for all Combined LAMBPLAN indexes. This review was undertaken to ensure that selecting on a Combined LAMBPLAN index delivers a similar direction and rate of genetic improvement to the equivalent index in the current Terminal and Maternal analyses, despite changes to the underlying breeding values.
3. All relevant enhancements to date apply to RBVs used in Combined LAMBPLAN indexes
Re-ranking of Combined LAMBPLAN indexes is expected. The re-ranking is driven by changes in the underlying breeding values resulting from enhancements released to date, including growth, carcase, eating quality, WEC, lambing ease, reproduction and wool updates. The index weightings themselves have not changed; rather, the breeding values contributing to the indexes have been updated. Animals previously not reported for an index may also become eligible for reporting under Combined LAMBPLAN.