Australia Rolls Out Overhauled National Breeding Objective for Dairy Genetics

Australia has ushered in a significant shift in dairy cattle breeding with the implementation of a revised National Breeding Objective (NBO) in December 2025, marking one of the most substantial updates to genetic evaluation in recent years. The changes are aimed at better aligning genetic selection with modern dairy production systems, farm economics and long-term sustainability goals.

The updated NBO introduces an enhanced genetic evaluation framework that recalibrates how Animal Breeding Values (ABVs) are calculated and interpreted. Central to the reform is a base update that now benchmarks genetic performance against cows born in 2020, replacing older reference populations. While this change has resulted in a broad-based decline in ABVs across many traits, industry experts stress that the drop does not represent genetic regression. Instead, it reflects a more contemporary and realistic baseline that captures the significant genetic gains already made across the national herd.

According to breeding and genetics specialists, base updates are a normal and necessary process to ensure breeding values remain relevant over time. As the average cow improves, the reference point must also move forward to prevent inflation of genetic estimates. The current adjustment provides producers with a clearer picture of where animals truly sit relative to today’s commercial dairy environment.

Interestingly, despite lower ABVs for several individual traits, Australia’s key selection indices have recorded gains. The Balanced Performance Index (BPI), Health Weighted Index (HWI) and Sustainability Index (SI) have all increased under the new system. This improvement is driven by revised economic weightings that better reflect current market conditions, including updated milk price assumptions and a rebalancing of the relative value of milk fat and protein.

Breed-level impacts vary. Holstein and Jersey cattle have both recorded higher ABVs for overall type and mammary traits, reflecting continued progress in conformation and udder health. However, Holsteins have experienced a decline in fertility ABV, largely because of genetic improvement across the wider population, which has lifted the average benchmark. Jerseys, meanwhile, have seen a notable reduction in milk litres ABV, again linked to the base change and revised economic emphasis rather than an actual loss in productivity.

Beyond recalibration, the new NBO introduces several structural enhancements. These include optimum expression markers for type traits, which discourage extremes and promote balanced, functional animals suited to Australian farming conditions. A revised model for Survival ABV has also been incorporated, placing greater emphasis on longevity and resilience rather than short-term production alone.

Industry bodies note that the updated breeding objective reflects a broader global trend in dairy genetics, where profitability, animal health, fertility and environmental sustainability are increasingly prioritised alongside yield. By integrating these elements more effectively, the revised NBO aims to support dairy farmers in breeding cows that are not only productive but also robust, efficient and capable of thriving under variable climatic and economic conditions.

Overall, the changes are expected to strengthen confidence in Australia’s genetic evaluation system and provide a more reliable foundation for breeding decisions that underpin long-term farm profitability and industry resilience.