BeefAI™ Champion — Methane Emission Intensity (MEI) Proxy Methodology: An EBV-Derived Genetic Proxy for Enteric Methane Efficiency in Australian Angus Cattle

This technical report describes the Methane Emission Intensity (MEI) proxy module implemented within the BeefAI™ Champion platform's APEX (Angus Percentile Excellence) scoring engine. MEI provides a relative genetic proxy for enteric methane efficiency in Australian Angus cattle, derived entirely from Estimated Breeding Values (EBVs) published through the TransTasman Angus Cattle Evaluation (TACE). The model synthesises three EBV-derived biological drivers — Net Feed Intake (NFI-F, 55%), Mature Cow Weight (MCW, 30%), and growth efficiency (CWT:600D ratio, 15%) — each normalised to TACE percentile position and combined using biologically informed weighting. The proxy enables producers to evaluate bulls for methane efficiency potential alongside traditional production traits during sale catalogue analysis, without requiring direct methane measurement. Aligned with MLA's Carbon Neutral by 2030 (CN30) roadmap.