Can UK livestock production be configured to maintain production while meeting targets to reduce emissions of greenhouse gases and ammonia?

We used a Life Cycle Assessment approach to determine whether the inherent differences in emissions to air among existing livestock production systems could be used to reconfigure the UK livestock sector in order to meet current greenhouse gas (GHG) and ammonia (NH3) targets while maintaining production at current levels. Output, defined as financial value, was optimized across all sub-sectors. Using current management systems the greatest livestock output that could be maintained, while meeting emission reduction targets, was 84% of current. Adopting the most appropriate manure management practices and improved feed conversion ratio enables a further increase in outputs to 86% of current. Dairy production could be maintained at 84.1% of current if all production arises from high-yielding herds with autumn calving, all dairy cow manure is managed as slurry and diets to reduce rumen fermentation are adopted. Increasing the proportion of calves obtained from the dairy herd by 10% could maintain beef production at 85% of current. Raising finishing pigs on slurry systems, raising sows and weaners outdoors, finishing pigs at either 89 or 99 kg and improving dietary nitrogen use efficiency could maintain pig production at 87.5% of current. Manure drying within poultry buildings, immediate incorporation of poultry manures to tillage land and reduced protein feeds would allow 82.2% of current poultry meat production. Eliminating free-range egg systems and drying manure within the building could maintain egg production at 85.5% of current. Replacing lowland sheep herds (other than organic) with upland production could maintain sheep output at 86.4% of current.