At May’s Pigs Tomorrow conference, the results of unique research into the environmental and animal welfare impact of different pig systems, along with a review of the carbon tax model now in place for Danish farmers, offered fascinating insights on the complex challenge of sustainability.
Dr Harriet Bartlett, research fellow at the University of Oxford, has found it is possible to deliver both good welfare and a low environmental impact in any type of pig production system and, while trade-offs do exist, they are not inevitable.
Asking ‘What’s the best way to produce pigs?’, she presented her groundbreaking research that involved a full range of pig production systems across 150 pig farms in the UK and Brazil, with categories including Red Tractor, RSPCA Assured, outdoor-bred, free-range, organic and woodland farms.
The aim was to scientifically investigate the assumption that, as one thing gets better, another gets worse, measuring the effect of pig farming on land use, greenhouse gas (GHG) emissions, antimicrobial use (AMU) and welfare outcomes.
Dr Bartlett carried out extensive work to ensure rigorous and comparable measurements of these impacts, developing new or more accurate models.
Results showed some positive correlations – for example, low land use was typically associated with lower GHG emissions and where the data showed welfare was better, AMU was also lower.
As expected, there were also trade-offs, with Red Tractor farms typically having better land use and lower GHG emissions than the outdoor systems, particularly organic and woodland.
But Red Tractor farms typically have lower welfare and higher AMU than the outdoor systems.
“However, trade-offs are not inevitable and there is the possibility for all farms to optimise their system,” Dr Bartlett said.
The data identified a small number of optimal units – ‘bright spots’ – achieving good results (top 50%) for all four impact areas.
They included Red Tractor, RSPCA and woodland farms, so no particular label type or husbandry type predicts the results, Dr Bartlett explained.
“There was nothing unique to these farms. While that’s frustrating, I also think it’s exciting and promising. While there is no silver bullet, there is a lot of possibility for lots of very different farms to be a part of the solution,” she said,
“I think this research is strong evidence for widespread measurement of outcomes and rewarding farmers based on these.”
Denmark’s carbon tax means
An ambitious plan for Danish agriculture – the Green Tripartite Agreement, which includes a carbon tax model – is set to shape the pig sector for the next two decades, Lisbeth Henricksen, executive vice-president for innovation at SEGES Innovation, told the conference.
The agreement has brought together not just government, but also many others, including farmers, trade unions and environmental groups.
“Our challenge is how to put this into practice for farmers,” said Mrs Henricksen.
“Collaboration is crucial. We’ve established local groups who have the job of planning land use in their area. Coming up with local solutions involving local stakeholders will hopefully avoid regulation.”
Denmark produces three times more food than it consumes. Agricultural emissions account for one-quarter of national emissions, a much bigger proportion than in the UK.
Many pig producers are also arable growers in Denmark and the agreement means 400,000ha will be taken out of agricultural production, with the equivalent of €5.8bn allocated to buy the land and establish green projects, including planting forests and protecting coastal ecosystems.
This will be funded by the carbon tax, which is currently focused on methane emissions from livestock production, which farmers will be required to pay from 2030 (€40/t of carbon dioxide equivalent in 2030, increasing to €100 by 2035).
However, there will be a 60% basic tax deduction for achieving average emissions from existing livestock buildings, with further tax deductions available to farmers who implement climate change mitigation measures and technologies.
“A lot of the mitigation measures have been fully tested and are ready to go, but they still need to go through the official approval process for their ability to reduce greenhouse gases,” Mrs Henricksen explained.
Mitigation measures for pig farms include:
- Frequent removal of slurry
- Reducing slurry temperature using cooling technology
- Slurry additives (chemical or biological)
- Using methane for anaerobic digestion, then using the digestate as fertiliser
- Biofilters in slurry tanks.
“The challenge for farmers is that they are still running a business and they have to work out how to do all this and still be financially viable,” she said.
Farmers have become more positive about the policy over time, as it delivers opportunities and the local groups offer the chance to work solutions out for themselves, she added.
Standardised measuring
Mrs Henricksen and Dr Bartlett were joined by indoor pig producer Jack Bosworth, from F J Bosworth & Sons, Norfolk-based outdoor breeding unit manager Rob McGregor and AHDB pork sector council member Hugh Crabtree for a lively panel discussion that highlighted the challenges around measuring environmental outcomes.
Mr Bosworth said that, for their long-standing family business, sustainability partly means longevity. “The changes we’ve made so far have been more financially driven than environmentally,” he explained.
“That will be the case until the industry has a better way to get the data and calculate environmental impact.”
They are currently making use of slurry on arable land, using electronic sow feeders to improve feed efficiency and milling cereals for pig feed at night to save energy costs.
Mr McGregor has been focused for many years on improving the environment and reducing emissions – for example, by planting cover crops on sow paddocks to protect the soil and finding the best ways to maintain the cover over time, which helped extend the life of the sites.
He has also focused on extending the life of farm equipment and the sows themselves.
Mr Crabtree chairs an AHDB Pork Environment Roadmap Steering Group, with integrators, processors, independent producers and technical experts all working together and willing to share data and knowledge.
“To estimate where we are now, we repeated the lifecycle assessment up to the farm gate,” Mr Crabtree said. “There’s now a roadmap to be completed this year, which will be a changing picture, as we gain new insights.”
Mr Bosworth stressed that having a consistent measuring tool is the priority for improving industry sustainability.
“The bit we’ve got to get right is to know where we are, to be able to improve. We’re proud of what we do, but we need to be able to trust the data and, longer term, we could go for net-zero branding on our products,” he said.
Different carbon calculators give different answers and there are now so many options. Dr Bartlett said the University of Oxford is trying to find a way to standardise the calculations used across the industry.
“Even if farms look like they are similar on all indicators, we don’t actually know until we’ve done the maths,” she said.
She reiterated the need to focus on outcomes, rather than assuming a particular type of production is better environmentally than others.