Establishing the Benchmark for Carbon in Free Range

Published on : 25 Feb 2026

The assessment has been carried out using the Alltech E-CO2 Poultry Environmental Assessment tool...

The March issue of the Ranger includes a full carbon footprint assessment for the BFREPA average performance flock, produced using the same assumptions that underpin the ADAS costed flock figures published each year.

This is a deliberate and significant step. The ADAS costed flock has become the industry reference point for understanding production costs on a like for like basis. Its strength lies in the discipline behind it: consistent assumptions, transparent inputs and a methodology applied in exactly the same way year after year. That consistency has given the model credibility and allowed it to be widely used and trusted across the sector.

By applying those same principles to carbon footprinting, BFREPA is establishing an equivalent reference point for environmental performance. The carbon assessment presented here is built using the identical flock structure, performance assumptions and management data that sit behind the ADAS costed flock. It reflects a realistic free range system, not a theoretical exercise or a selective example.

The assessment has been carried out using the Alltech E-CO2 Poultry Environmental Assessment tool. It measures greenhouse gas emissions up to the farm gate and converts carbon dioxide, methane and nitrous oxide into a single figure expressed as carbon dioxide equivalent. The headline results are shown as kilograms of CO2e per dozen eggs and per kilogram of eggs, representing the total emissions generated on farm divided by total egg output.

Carbon footprint is therefore not simply an environmental statistic. It is a measure of efficiency. Producing more eggs from the same inputs spreads emissions across a greater volume of output and reduces the footprint per unit. Feed efficiency, bird health, persistency of lay and mortality all directly influence the final carbon score.

For benchmarking to have meaning, consistency is essential. Carbon figures can only be compared when the same boundaries, assumptions and calculation methods are applied. Just as production costs lose relevance if calculated in different ways, carbon data becomes difficult to interpret when different appraisal models are used. The methodology behind this assessment ensures that comparisons are valid and grounded in the same framework.

The report breaks the footprint down by source, showing clearly where emissions arise within the system. Feed is the largest contributor, reflecting emissions associated with crop production, fertiliser use, land use change, transport and feed processing, as well as the carbon intensity of individual ingredients. Feed conversion ratio and bird performance determine how efficiently those emissions are converted into eggs.

Manure emissions are split into methane produced during storage and nitrous oxide arising from storage and land application. Nitrous oxide has a particularly high global warming potential, which is why manure management remains an important factor in overall carbon performance.

Energy, fuel and water use are included, along with transport emissions associated with moving feed and birds between sites. While these typically contribute less than feed, they remain relevant for assurance, reporting and cost control.

The assessment also accounts for embedded emissions in pre lay hens. Pullets arrive on farm with an existing carbon footprint reflecting rearing inputs. Strong pullet quality and lifetime performance allow those embedded emissions to be spread over more eggs, improving overall efficiency.

Performance data within the report includes flock size, age and bodyweight at key stages, total eggs produced, eggs per hen housed, proportion of seconds and mortality. These figures demonstrate clearly how day to day management decisions translate directly into carbon outcomes.

As part of BFREPA membership, producers are entitled to one fully analysed carbon assessment free of charge. This is a comprehensive seven page report produced using the same methodology shown here. It provides a clear carbon score for an individual flock, alongside benchmarking against the BFREPA average, other BFREPA producers and the Alltech average.

Through BFREPA’s ongoing relationship with Alltech, additional support is available to members who require assistance understanding the calculations or interpreting their results. The aim is not simply to provide a number, but to ensure members understand what sits behind it and how it links directly to flock performance.

As environmental reporting becomes increasingly important for assurance schemes, customers and supply chains, the need for trusted, comparable data will only grow. By presenting the BFREPA average carbon footprint alongside the ADAS costed flock, the intention is to establish a recognised industry benchmark for free range egg production, built on the same rigour and discipline that have made the ADAS costed flock the reference point it is today.

Take control of your carbon. This is your report, created from your own flock data, built around your system and owned by you. It stays with you, not the packer, and moves with you from one packer to another without the need to repeat the work or recreate the assessment. The report remains valid as long as the underlying production system remains consistent. Where fundamental inputs such as feed formulation or sourcing change, the carbon assessment would need to be updated to ensure the figures remain accurate and directly comparable.

Click here to download the comprehensive 20 page A4 booklet which focuses on the ADAS flock, explaining in detail how our carbon system works.