Reducing emissions from concentrate feed
Approximately 20% of laying poultry diets are composed of soya. Imported soya often has a very high carbon footprint due to land-use change and transport. Replacing soya with alternatives could significantly reduce the carbon footprint of poultry diets, but is challenging to do.
Locally sourced alternatives, such as rapeseed meal, peas, beans and lupins, are not favoured for many reasons, including their lower protein content when compared to soya, presence of anti-nutritional factors, the difficulty of growing them in the UK, and the increased cost.
Certified soya which is sustainably sourced is another option, but is currently difficult to obtain and more expensive than conventional soya. In the future, the feeding of insects or algae could become an option.
Reducing emissions associated with poultry manure
Poultry manure management also offers great potential for reducing GHG emissions associated with egg production. The most feasible strategies to reduce the carbon footprint are to export manure as feedstock for an anaerobic digester, or to sell manure as fertiliser.
Improving husbandry practices to reduce the carbon footprint
The carbon footprint of eggs can be lowered further through improved husbandry practices of laying hens. Reducing casualties and increasing layer rates both have a positive impact on footprints; the CO2e per dozen eggs drops dramatically when comparing a high-performance laying flock, with 15 more eggs per layer per annum than average, against an average laying flock.
Selective breeding to improve laying hen carcass quality could further reduce footprints by allowing spent hens to be sold for meat; a proportion of their GHG emissions would therefore be allocated to the meat, rather than the egg.