Pig sector - reducing greenhouse gas emissions: bringing home the bacon - report

Report from the Scottish Pig Industry Leadership Group, one of the farmer-led groups established to develop advice and proposals for the Scottish Government. It focusses on how to cut emissions and tackle climate change, something that was re-emphasised in the updated Climate Change Plan.

6. The Solutions

Maximising Input Efficiency

Feed is the biggest input in pig production accounting for two thirds of all costs. Using it as efficiently as possible will have the biggest effect on GHG emissions.

1. Protein levels in feed have been reduced by up to one third and this has resulted in a corresponding reduction in ammonia (NH3) and nitrous oxide (N2O) emissions. Currently there is no reward for reducing protein in diets. The NVZ and IPPC regulations don't take account of the resulting lower Nitrogen in muck and slurry. Feed recording needs to be improved to calculate on-farm efficiency levels.

Recommendation 1 : Encouragement to complete simple on-farm feed and slurry recording to allow baseline GHG emission levels for the sector to be established.

2. Cereals make up around 80% of the total ingredients in pig feed by volume. Most of Scotland's pig farmers mix their own feed on farm. 48% of the cereals are grown on farm with another 27% purchased from neighbouring farmers. This keeps the carbon footprint very low, as less transport is involved. Slurry and muck from the pigs are used to grow the crops thus reducing the need for inorganic fertiliser.

Recommendation 2 : On-farm auditing tools to recognise 'home grown' and/or 'locally sourced' cereals which supports a lower carbon footprint per farm.

3. Soya use is controversial due to deforestation in Brazil. There is a moratorium amongst soya buying companies not to buy soya from recently deforested land but this can be evaded by grazing cattle on the land before they grow soya on it. Clearly this is a major multinational political issue and unilateral moves in Scotland are likely to simply offshore the problem. More sustainable supplies are available from the USA and some from Argentina. Soya is ideally suited to pig diets and is highly digestible, whereas peas, beans, and lupins have lower protein and are less palatable. Historically, swill feeding or meat and bone meal was used but this has been banned due to the significant disease risks associated with it. There has been more success using rapeseed meal to substitute for soya (even though the amino acid profile is not as well suited for pigs) and oilseed rape is also easier to grow in the Scottish climate. Bacterial protein grown on a substrate and insect derived protein could be used in the future. Synthetic amino acids are already being used effectively to reduce soya inclusion rates. All of these alternatives are currently more expensive, which is barrier to uptake when competing against imported pigmeat that would still use soya. Removing soya altogether could be detrimental to Climate Change objectives because less efficient diets would increase feed use with a consequent rise in GHG emissions. A targeted reduction is far more realistic and new research should be geared towards this.

Recommendation 3 : Research and Development commissioned into alternative protein supplements and the effect they have on reducing GHG emissions. Consideration should be given to the wider effects of using alternative protein sources.

4. Training opportunities specific to pig farms are in short supply. With labour being the second biggest cost on pig farms, support is required to provide CPD for farm managers and staff to enhance their skills and knowledge. This challenge can be partly addressed through Modern Apprenticeship Schemes. Currently the cooperative Ringlink Scotland and land-based training provider Lantra facilitate opportunities for young people to be introduced to and experience working on farm. AHDB Pork in England also have extensive training programmes for modern pig producers.

Recommendation 4 : Funding to deliver specific on/off-farm training and develop pig specific training material would boost interest amongst trainees and employers.

5. Knowledge transfer and exchange is necessary to share expertise and improve the overall efficiency of the Scottish pig sector. The Pig Monitor Farm has been an effective mechanism for sharing knowledge amongst farmers, staff, vets, government bodies and the ancillary industry, acting as the central hub for KE in the Scottish industry. A new 5-year project would allow this to continue. The Knowledge Transfer and Innovation Fund has also been successfully used for projects that have advanced pig health and product quality.

Recommendation 5 : Knowledge Transfer and Exchange should be continued with a new Pig Monitor Farm programme and continuation of the KTIF scheme.

6. Energy is used for feed processing, heating, lighting, cleaning, and ventilation. Several pig farms have invested in renewable energy over the years to help off-set the energy which they are using. Renewable energy has the potential to greatly reduce the carbon footprint of pig units provided the national inventory does not record it somewhere other than in the agriculture category. There is scope for better measurement of energy use so that waste is reduced, and savings made:

  • Anaerobic Digestors use muck and slurry to create energy but usually also utilise other feedstocks for example silage from grass, rye, or maize.
  • Biomass Boilers run on wood chips or pellets to replace heat from fossil fuels or electricity.
  • Solar Panels either on shed rooves or on land to provide electricity.
  • Wind Turbines of various sizes to provide some or all the electricity requirements of the farm unit.

Any new grant scheme should ensure dividend is targeted at both large and small units which may have other diversified food production on site.

Recommendation 6 : Support to invest in renewable energy initiatives for example anaerobic digestors, biomass boilers, solar panels, and wind turbines to offset the energy requirement on pig farms.

Utilising Best Technology

Pig farms have used highly efficient genetics to remain competitive and there have been dramatic improvements in the output from breeding herds over the last 10 years. On-going investment in buildings, ventilation and feeding systems will all help to reduce GHG emissions.

7. New building investment since 2011 has been minimal due to the abolition of the Agricultural Buildings Allowance. Support to invest in new pig housing facilities could incorporate improved welfare, novel energy saving measures and a better atmosphere to improve pig health and welfare and grow pigs more efficiently. Variable returns and an uncertain market have reduced investment in buildings and the removal of capital allowances on buildings has been a disincentive. Furthermore, local planners have frequently blocked projects that improve premises to reduce GHG emissions.

8. Ventilation in many sheds needs either an overhaul or replacement. Good ventilation is essential for maintaining good health, welfare, and performance in a pig herd. Modern fans use far less energy than older systems and even the simple installation of baffles can have dramatic results. Recent studies have shown that investment and training are required to improve the environment for pigs and people.

9. Insulation of sheds will improve the atmosphere and reduce wasted energy. Pig buildings could be assessed and given a thermal insulation rating. Investment in insulation could then be targeted at problem buildings. Newer outdoor pigs arks have greatly improved insulation giving demonstrable benefits for sow condition and piglet comfort.

Recommendation 7 : Capital grant funding and/or annual investment allowances as well as supportive planning legislation will encourage investment into building facilities which improves both herd and environmental efficiency.

10. Legal requirements around pig buildings are periodically reviewed. In 1999, there was a unilateral ban on sow stalls in the UK that resulted in 40% of the UK pig herd going out of business. This was predominantly because food labelling laws did not allow the difference to be clearly communicated to UK consumers and so cheap EU imports from housing systems banned in the UK flooded the market. It is imperative that the lessons from that need to be learnt for any future changes to housing systems. The industry is not resistant to change and indeed market sentiment often moves more quickly than legislation, however, any change needs a long lead time, grant support to assist with investment and labelling rules that protect from unfair competition.

Recommendation 8 : Any proposed changes to legislation need to consider their impact upon progress to reduce GHG emissions and if changes are required, sufficient lead time be given to enable the required investments to be made along with relevant grant support.

11. Data recording on most Scottish pig farms is excellent for the breeding herd and so improvements are easy to measure. Feeding herd information however is not currently readily available because it is time-consuming to weigh pigs and recording feed use accurately is difficult to achieve in individual pens. QMS fund the provision of a recording system so use of the feeding herd modules needs to be encouraged through training or advice.

12. Data integration should be encouraged between the suppliers of computer control systems for feeding, ventilation, and energy so that they can communicate with each other. Currently, the computers are specific to these individual operations but enabling them to communicate would create readily available information to monitor input use.

13. Electronic identification systems and automatic weighing should be developed and installed to enable the performance of the growing pig to be easily measured. This relies on being able to quickly identify and trace individual pigs. Pigs must meet a tight market specification, so labour-saving weigh systems would enable processor requirements to be targeted efficiently.

14. Feeding systems that reduce waste would result in cost savings and reduced emissions. Any saving is significant because feed is the biggest input. Automated systems should also improve welfare and save labour. SRUC modelling identifies precision feeding as a practice that gives a positive return on investment as well as environmental benefits.

15. Modern LED lighting gives significant savings in energy and improves pig performance.

Recommendation 9 : Financial support to invest and install equipment to improve production, energy and environmental efficiency.

Tackling Livestock Disease

The health of the Scottish Pig Herd has improved significantly due to individual herds undergoing a total or partial depopulation and collaborative approaches to area disease reduction. This and the targeted use of vaccines mean that there is an increase in pig performance and a reduction in antibiotic usage. Healthy pigs utilise inputs more efficiently and so have a lower carbon footprint, quite aside from the ethical priority of ensuring that livestock are reared in the most humane manner possible.

16. Wholesome Pigs (Scotland) has led collaborative initiatives to improve health amongst Scottish pig farmers for 20 years, with remarkable levels of success. Data is collected and shared from abattoirs, farms and vets allowing coordinated interventions that are far more effective than individual farmers doing their own thing. The critical enabling step took place in 2015 when all producers agreed to share pig health information with each other, removing the main barrier to coordination on local and regional levels.

17. Quarterly vet visits by vets specialising in pigs helps to reduce the presence of disease on pig farms and ensures that good animal welfare is maintained.

18. Early warning system – the Scottish Pig Disease Control Centre (SPDCC) is an industry-led initiative that has the simple objective of minimising the welfare and economic impacts of serious disease outbreaks, such as Swine Dysentery and Porcine Epidemic Diarrhoea. It needs more resources so it can achieve this objective effectively.

19. The Electronic Medicine Book (eMB) shows the progress that has been made by farmers and their vets to reduce antibiotic usage, (see the chart below). These figures are for the UK for reasons of confidentiality. Figures are generally lower for Scotland except for 2019 when there was an outbreak of Swine Dysentery (the impact of which was reduced by the SPDCC):

UK Pig Antibiotic Usage (mg/kg)
Chart illustrating the reduction in pig antibiotic usage between 2015 and 2020

( AHDB ; *2020 figure only includes first six months )

20. Investment in buildings, ventilation and insulation can create a better atmosphere and reduce levels of disease within a pig herd, not least because it is impossible to disinfect wood which was commonly used in older pig buildings. Local planning regulations need to reduce the obstacles pig producers have to improving premises to reduce GHG emissions.

21. Water quality and delivery is vital for pig health. Pig farms have greatly reduced in-feed medication and systems to acidify water can help to alleviate health problems. In-water medication system enable more precise and rapid delivery, reducing waste.

22. Site biosecurity to prevent the entry of disease should be a top priority on pig farms. Fencing, disinfection, wheel washing and CCTV can all help.

23. Depopulation/repopulation – a partial or total depopulation is necessary where there is a high disease burden on a herd and antibiotic usage is too high. These both require significant financial investment. PRRS (Porcine Reproductive and Respiratory Syndrome) is a pig disease which can have a serious economic impact on pig farms due to its immune-suppressive effect and partial or total depopulation are the most effective approaches to its control.

Recommendation 10 : Financial incentives to reduce, control, prevent and eradicate diseases within the Scottish pig herd.

24. Biotechnology research has a great deal of potential in pigs, for example, at the Roslin Institute where gene editing has developed pigs that are resistant to PRRS. There are consultations on-going currently about whether gene editing should be permitted, and questions also remain about customer acceptance of such practices. Nonetheless, the Scottish

Research Institutes are global leaders in this field and should be supported to continue the under-pinning research into technologies that will enhance the ability of industry to produce more with less emissions.

Recommendation 11 : Research and development into biotechnology solutions to breed disease resistance pigs and reduce environmental impact.

Turning Wastes Into A Resource

Slurry and muck are the major by-products of pig farming. These are already used to grow grass and crops in mixed farming systems, all of it used either on the production farm or an immediate neighbour. Better utilisation and accounting of slurry and muck in soil nutrition would result in reduced usage of inorganic fertiliser. Slurry and muck can also be good sources of renewable energy, but large amounts of capital expenditure are required to unlock this resource.

25. Reducing inorganic fertiliser – slurry and muck have been used effectively in mixed farming systems to reduce the requirement for inorganic fertiliser. QMS commissioned a study that calculated an average saving of 1,021 kg CO2/ha saving in GHG emissions by substituting the inorganic fertiliser with slurry with average nutrient content of Scottish pig units. This could be done more effectively through better training.

26. On-farm slurry analysis of slurry and muck is not widespread. This needs to be encouraged so that inorganic fertiliser can be better targeted. NVZ regulations should be modified to take account of slurry and muck analyses.

27. Slurry storage needs to be increased to utilise slurry effectively and protect against future changes in legislation. Existing slurry storage is also in need of replacement and covers on stores reduce ammonia emissions, maintaining the level of nitrogen in the slurry so that it can be utilised by crops. Note that SRUC modelling shows that there is no financial return on investment from covering slurry stores so grant incentives would be required.

28. Slurry distribution and application systems reduce the reliance on tractors and tankers using fossil fuels to transport slurry. They also enable application and incorporation at times more suited to the crop when ground conditions with tankers may be challenging. Slurry Injection reduces emissions and increases the level of nutrients that are available to the crop.

29. Slurry cooling – heat can be removed from slurry and pumped to sheds on the farm that require heating. This would be difficult and very expensive to retrofit. It should be encouraged in any new building that can utilise it.

30. Slurry acidification – acidification of slurry reduces the levels of ammonia in pig sheds by keeping it in the slurry as ammonium. GHG emissions are reduced and the environment in the pig shed is improved. The slurry also has a greater nutrient value. This again is expensive to retrofit but should be encouraged in any new building.

31. Hydrogen electrolysis –This process removes methane from slurry and converts it into hydrogen which could in the future be used to fuel machinery. This merits more exploration to understand the potential and limitations.

32. Air scrubbers and biofilters could be fitted on new buildings to reduce emissions. Settling ponds and swales can be constructed to reduce the risk of contamination by surface water running though farms.

Recommendation 12 : Grant support should be provided through the Agricultural Transformation Programme to encourage uptake of the above measures.

Adding Value and Building Producer Confidence

Pig producers in Scotland operate in a market environment and most of the capital required to deliver the on-going investment needed will come from the private sector. As such, confidence that there will be longer-term market opportunities is essential to enable a return on investment to be calculated.

33. Clear and positive leadership from Government could counter local and national perceptions and encourage a thriving Scottish pig sector with a sound environmental footprint. Ireland and New Zealand are examples where supportive government has created a thriving agricultural industry. The Good Food Nation Bill is an opportunity to outline how the multiple objectives of affordable, nutritious food can be combined with the progress towards net zero GHG emissions whilst maintaining a thriving rural economy.

Recommendation 13 : Confidence provided by positive leadership from Scottish Government.

34. Cooperative marketing is already widespread in the pig industry, enabling family farms to thrive within an increasingly concentrated processing and retailer environment. Formal Producer Organisation status would enable investments to be made through vertically integrated supply chains, strengthening resilience in these supply chains by engaging the end user - consumers. Initiatives such as the QMS Butchers club and Scotland Food & Drink Buy Local directory are important so that people know where Scottish Pork can be found. Scottish Pork should be more visible and valued in the list of sustainable Scottish products than is currently the case.

Recommendation 14 : Producer Organisations should be extended to the pig sector and investment schemes adapted to allow vertical investments by supply chain partners.

35. Processing infrastructure for slaughter and adding value is limited in Scotland, leaving the supply chain very exposed if anything happens to Quality Pork Ltd at Brechin. Grant support to encourage processing investment should be continued and a Scottish food resilience map be developed to identify where strategic investments could help to build resilience. The current challenges of Covid closures have heightened awareness of the importance of food supply fragility.

Recommendation 15 : Grant support should continue to the processing sector through a successor to the Food Processing, Marketing & Co-operation Scheme.

36. Scottish pork reared, processed, and consumed here has a lower carbon footprint than that of many of the imports. The survival and expansion of our home-based industry is the best way to negate Climate Change by reducing emission offshoring. Quality Meat Scotland have a key role in marketing this brand to secure the loyalty of Scottish consumers. If gold standard GHG credentials can be demonstrated by the pork sector, there may also be premium export opportunities to sell Scottish Pork into markets that value these credentials. There may also be potential to participate in the wider branding opportunities proposed by other reports such as the Suckler Beef Climate Scheme or Scotland Food & Drink.

37. New Entrants require confidence and support to get established. There have been several farms that have recently set up finishing pig units but very few new entrants to pig breeding in the last 20 years due to the higher capital cost. This needs to be addressed to future proof the Scottish pig herd and reduce the age profile of pig farmers. New Entrants need encouragement and support.

Recommendation 16 : New Entrants need encouragement and support through both mentoring and financial assistance.

38. Research funding is nearly all spent on animal welfare at present and most of it will have very little effect on GHG emissions. There is scope for the research organisations in Scotland to focus on the issues in this paper that will reduce emissions. The Centre for Knowledge Exchange proposed in the Draft Strategy for Environment, Natural Resources and Agriculture Research is a logical next evolution of the SEFARI Gateway concept that has helped to improve the two-way communication between the pig industry and the research community over recent years. The Knowledge Transfer and Innovation Fund has also proved effective.

Recommendation 17 : Research and Development funding is required to make advancements in reducing GHG emissions and improving Knowledge Exchange.

39. Planning rules make it difficult for pig farmers to invest in new infrastructure. The planning costs are the same as other industrial buildings, but the return on investment is significantly lower, which acts as a barrier to new and existing farmers investing in pig buildings. There has also been historic resistance from some local authorities to granting planning approval for any pig farm projects, something that may be changed by guidance from Scottish Government.

Recommendation 18 : Local planning regulations need to address the obstacles pig producers have to improving premises to reduce GHG emissions.

How Should We Measure Progress?

40. Carbon emissions baseline levels must be established to determine where each farm and the sector sits currently. Platforms like SAOS' CarbonPositive are needed to identify a baseline for carbon sequestration, renewable energy production and the environmental stewardship of natural assets including water and biodiversity for every farm in Scotland. Currently, it is unclear how the national inventory captures improvements in efficiency and feed ingredient sourcing that have already had a sizeable impact on the actual GHG emissions of the sector. In particular, the concepts outlined in the Interim Report from the Farming for 1.50C Inquiry where the three different GHG's are split out have merit for pigs because Nitrous Oxide and Carbon Dioxide emissions are far more significant than Methane. Future progress can then be effectively measured and reported.

Recommendation 19 : Financial support to accelerate carbon emission baselining levels and inventory work.

41. Carbon audits performed annually would help to focus pig farming businesses on making improvements. The carbon auditing tools currently available require investment to improve the accuracy and ease of use for application on pig units without the use of consultants. There is scope for some input information to be supplied centrally rather than expecting farmers to find out, most notably by feed companies relating to the source of their raw materials.

Recommendation 20 : Financial support to complete annual carbon audits using improved measurement tools.

42. Sensors and regulatory reforms could be trialled to measure emissions outside and gas levels inside pig buildings and a review considered to find a more user-friendly alternative to the Integrated Pollution Prevention and Control Regulations (IPPC) to ensure that the sector is minimising damaging impacts on the environment. The performance of IPPC permitted pig farms in Scotland has generally been good, but the IPPC regulations were designed by the EU to regulate industrial sites with point-source pollution and has always proved challenging for both industry and regulators to apply to farms with diffuse pollution risks. Attention should be given to whether a more effective regulatory approach can be developed now that the UK is out with the EU.

Recommendation 21 : Trial sensors to measure emissions outside and gas levels inside pig buildings and review regulatory approaches to monitoring.


Email: are.futureruralframework@gov.scot

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