British pig farmers have achieved a £15.3m (US$19m) in savings on environmental mitigation costs, because of work done on updating ammonia emission factors, says an AHDB pig expert.
The achievement follows years of research and collaboration.
Zanita Markham, projects and engagements relationships manager, pork, at AHDB, who was the lead on a multi-year ammonia monitoring trial, said findings led to revised ammonia emission factors that are now part of the UK Environment Agency’s (EA) framework, potentially easing the path for future planning applications.
The initiative, she explained, stemmed from international air pollution agreements requiring the UK farming sector to reduce ammonia emissions by 16% by 2030, relative to 2005 levels. This target, enshrined in the UK government’s clean air strategy, sparked concerns among pork producers over outdated emission factors that failed to reflect current farming practices.
In response, around £250K of levy funds were invested to develop more accurate emission factors (EFs), said Markham.
The findings revealed that costly investments in new buildings, dietary changes, and slurry treatment technologies could be minimized, as the industry was already on track to meet the 2030 targets, said the AHDB representative.
The role of ammonia reductions
Ammonia emissions primarily stem from slurry management and nitrogen fertilizers. When released into the atmosphere, ammonia can combine with other compounds, contributing to smog, impacting human health, and damaging sensitive ecosystems.
Agriculture accounts for 88% of the UK’s ammonia emissions, with the pork sector contributing around 8%, according to data from Defra.
Under the UK’s Environmental Permitting Regulations (EPR), pig farms exceeding 2,000 pigs above 30 kg or 750 sows must secure environmental permits and comply with Best Available Technique (BAT) Associated Emission Levels (AELs).
“This means that permitted farms must ensure emissions do not exceed the stated levels and are required to adopt minimum standards of management practice and BATs. For example, altering the protein content of the feed, building type and design, slurry storage and management systems,” remarked Markham.
Monitoring and data-driven results
AHDB’s comprehensive monitoring project was initiated by Markham’s predecessor.
“Having taken up the baton from a former colleague – Nigel Penlington – I managed AHDB’s intensive study from start to completion. It was clear that by using the older EFs, UK pig farms were not going to be compliant with the BAT AELs.
“But the project provided updated data on the performance of different types of modern pig housing and evidence to support revising the ammonia emission factors for UK pig housing.
“The Pork Sector Council called for AHDB to take the lead and conduct more studies in the area. The initial outlay of levy investment was needed as there was little or no qualifying information to help relate EFs to current commercial performance, as the techniques previously used were limited and measurements followed no common protocol.
“Importantly, our ammonia monitoring, together with the other evidence available, has demonstrated that a lot of existing pig housing is already compliant.”
The studies highlighted that ammonia emissions on pig farms are generally lower than previously thought. For instance, the emission factor for finishers on straw systems has dropped to 1.88 kg of ammonia per animal place per year, down from 2.97 kg, reported Markham.
“For the pig sector, ammonia reductions of approximately 30% for finishers and 50% for weaners have been demonstrated, reflecting the great strides that producers have achieved already. We have seen the reduction in emissions from the industry by improving production efficiencies, feed, housing and slurry management.”
While most systems now meet regulatory requirements, exceptions remain. Fully slatted floors for pigs over 30 kg and dry sows still exceed BAT AELs, reported Markham.
However, producers can reduce emissions in these systems through dietary adjustments, improved building designs, and enhanced slurry management, she stressed.
Updated ammonia emission factors
The EA is due to publish the new set of standard ammonia emission factors (EFs). It is responsible for enforcing the EPR in England, and it uses EFs to assess the impact of permitted farms’ ammonia emissions on the environment, both during the permit application process and as part of annual pollution inventory reporting. Natural England uses them in ammonia dispersion modelling as part of planning applications, and Defra also uses them to estimate UK emissions of ammonia from pig production.
Markham emphasized the importance of continued investment, saying that this new baseline highlights the progress achieved, but that ongoing innovation and investment will be crucial to further reductions.
