This report contains an executive summary. As requested, it is reproduced here exactly.

Executive Summary

Research into the environmental impacts of pig and poultry production in the UK to date has primarily focussed on the direct impacts associated with excreta from housing units. However, these systems are also heavily dependent on a significant amount of bought in inputs, largely in the form of feed concentrate, with much wider implications for land use, environmental impacts, and climate change. These impacts are currently not well represented in the scientific literature with no single review of the holistic environmental impacts of the UK pig and poultry sectors having been conducted.

In this report, we explore the wider environmental risks from food produced in intensive pig and poultry units in the UK across a range of environmental factors - including biodiversity, climate, water quality, air quality, land use (both in terms of unit footprint and footprint of additional inputs), and water use. This report provides a robust, evidence-based overview of the environmental risks of pig and poultry production in the UK from available data.

Inventory of the Sector

The scale of pig and poultry production in the UK is significant, almost 1 million tonnes of pigmeat and 2 million tonnes of poultry meat are produced per year, breeding, growing and slaughtering in the region of 11 million pigs and 1.1 billion broilers. In addition, the UK has an egg laying flock of approximately 40 million chickens, producing approximately 12 billion eggs per year. Section 2 of this Report provides a detailed overview and high-level spatial distribution of the UK pig and poultry sectors.

Pigs

Pig units are located throughout the UK, but are often highly geographically concentrated. For example, of the 1,772 registered specialist pig holdings in England, 30% were in Yorkshire and Humberside, 26% were in the Eastern region, and 14% were in the South West. 15% of England's breeding pig population is located in just one council area - North Yorkshire CC. In Northern Ireland, just two District Councils contain 66% of the pig breeding herd and 69% of the fattening herd.

The majority of breeding herds in England and Wales fall outside of the current environmental permitting regime. In England, only 38% of the breeding herd was on farms which meet the threshold requiring an environmental permit. In Wales, none of the breeding herd is on units of more than 150 sows, and therefore all breeding pigs fall outside the environmental permitting threshold.

Poultry

Poultry units are similarly often highly geographically concentrated. Of the 2,485 specialist poultry holdings in England, 19% were in the Eastern region, 14% were in the East Midlands and 14% in the West Midlands, 19% were in the South West and 12% were in Yorkshire and Humberside. In Wales, 55.8% of the total layer and broiler flock is located in Powys - this region has seen a dramatic increase in poultry numbers from just over 1 million in 2007 to around 5 million in 2020.

Whilst the proportion of poultry in units which require an environmental permit has risen in recent years, a significant proportion of poultry units fall outside of current permitting requirements. For example, in 2023 just 65% of poultry in Powys was in units of 35,000 or more animals (the threshold for permitting being 40,000).

Inputs and outputs from the UK pig and poultry sector

Typically, the environmental footprint of pig and poultry units is perceived to be small, with production concentrated within housed sheds or densely populated outdoor units. However, whilst the average areas of specialist pig and poultry farms are relatively small, the areas of land associated with pig and poultry production extend well beyond the unit 'footprints'.

Agricultural area used for feed

Pig rations are estimated by AHDB to include approximately 48% wheat, and poultry diets also consist predominantly of wheat. AHDB estimate that poultry feed accounts for 45% of total animal feed production in the UK. We therefore estimate that feed requirements for pig and poultry units include approximately 520,000-580,000 ha of wheat grown in the UK, equivalent to 34-38% of the UK's total wheat crop. This can be considered a conservative estimate for the UK as a whole as it does not account for those producers using on-farm mill and mixing of their own animal feed (i.e. not using purchased compound feeds), and it excludes Northern Ireland.

This land use has associated fertiliser and pesticide inputs which are not typically ascribed to the pig and poultry sector, despite being used to grow commodity crops which are directly linked to the pig and poultry supply chain. We calculate that the associated pesticide use with growing 580,000 ha of wheat equates to 2,621 tonnes of pesticides across 8.32 million treated hectares, of which 24.4% are fungicides (by weight).

UK pig and poultry feed also includes soyabean meal, requiring land use outside the UK of an estimated 730,000ha. However, environmental impacts outside of the UK fall outside the scope of this report.

Excreta Production

The amount of excreta resulting from pig and poultry production in the UK is in the region of 10.4 million cubic metres per year. We calculate that this results in total outputs of approximately 97 million kg/yr nitrogen and 64 million kg/yr phosphate. The generation of excreta outputs is also highly concentrated, linked to the nature of the pig and poultry sector in the UK. In one single council area in England, North Yorkshire CC, the combined volume of excreta from pig and poultry production each year is 1.7 million m3. 69% of all pig excreta in Northern Ireland is produced in just two District Council areas.

In Section 3.4 of this report, we explore the land area required for spreading excreta under different nutrient loading limits in detail. Our findings show that even where manure from pig and poultry units is applied to land within Nitrogen loading limits, it would likely exceed the phosphorus demands of the crop. When spreading pig and poultry manures to achieve phosphorous crop demands, the land area requirement to maintain a phosphorus balance is significantly higher than the land area requirement under a N loading limit of 170 kg/ha.

Geographic concentrations of the pig and poultry sectors in particular hotspots mean that maintaining N and P balances in soils is challenging, and the land area required to maintain a phosphorus balance is very large. Of particular note are the council areas of Breckland and South Norfolk, and North and North East Lincolnshire. In both Council areas, the land area requirement for spreading excreta from pig and poultry units in order to maintain a phosphorus balance, as a share of the total farmed area, is 61%.

Given that in reality pig and poultry excreta will not be spread evenly across these areas due to logistical challenges of transporting and applying pig/poultry manure and slurry, it is likely that many farms here will be in significant phosphorus surplus - and by extension, a significant source of phosphate losses into the environment.

Environmental risks and impacts of pig and poultry production in the UK

Focus to date on the environmental impacts of pig and poultry production has largely been on the spreading of excreta outputs of these units which, while significant, do not convey the full extent of the environmental footprint of these systems. Wider impacts on soil quality, water quality, biodiversity, and land use are associated with the supply chains and food systems which underpin these units.

The environmental impacts associated with soil erosion, fertiliser application, and pesticide use on the significant land area associated with producing feed for pig and poultry units are likely significant, but currently fall outside of any reporting or permitting on the environmental impacts of pig and poultry units.

The findings of this report also show that the majority of breeding sows in England fall outside the environmental permitting regulations, alongside significant proportions of other pig populations across the UK. This means that regulators lack a key route to managing the potential environmental impacts of these enterprises. In contrast, a high proportion of poultry is in larger units falling within the environmental permitting regulations. However, even where the permitting regime applies, not all producers appear to be adopting best practice in manure storage and application. The nutrient pollution issues in the River Wye catchment highlight the impacts that locally-concentrated manure applications in excess of crop need and soil capacity can bring.

AI suggested related notes

These notes appear semantically similar based on Smart Connections embeddings:

• The Hidden Harms of Factory Farms (Conservative Animal Welfare Foundation) (similarity: 74.1%)
• The Future of Food Security in the UK (Conservative Animal Welfare Foundation) (similarity: 72.8%)
• Calculating the environmental damage caused by UK factory farms (similarity: 71.1%)