The Wildlife Trusts commissioned a report by Cumulus Consultants on the environmental impact of pig and poultry farming. It says pollution from the sectors is harming rivers, the wider landscape and wildlife. The study estimates waste from producing millions of pigs and billions of birds and eggs at about 10.4 million cubic metres a year, roughly the equivalent of 4,160 Olympic-sized pools. It highlights high nutrient levels in manure, including nitrogen and phosphorus, which make spreading on farmland difficult and contribute to pollution in rivers that affects water quality and freshwater biodiversity. The researchers identify hotspots where production is most concentrated.

It notes the broader land footprint linked to feed production. More than a third of the UK’s wheat crop goes to pig and poultry feed, with much of that land farmed using fertilisers and pesticides that can pollute the countryside. Conservationists say the scale of the industry extends beyond the intensive units and calls for measures to cut pollution and help meet environmental targets. The report estimates the UK breeds about 11 million pigs and 1.1 billion chickens for meat each year, along with around 40 million laying birds producing about 12 billion eggs. The authors warn that much of the impact falls outside current reporting or permitting regimes.

England-specific data shows 30% of pig holdings are in Yorkshire and Humberside, and 28% of poultry holdings are in the Midlands, with around an eighth of England’s broiler flock in Lincolnshire. In Wales, 56% of the poultry flock is in Powys, and in Northern Ireland two council areas account for about two-thirds of pig holdings. The report estimates 520,000 to 580,000 hectares of UK wheat are used for pig and poultry feed, alongside 2,621 tonnes of pesticides. It notes many breeding sows operate outside environmental permitting rules and that some farms do not adopt best practice, pointing to pollution in the River Wye catchment. Barnaby Coupe, senior land use policy manager at the Wildlife Trusts, said: “Assessment of the environmental impacts of pig and poultry production to date has largely focused on the immediate risks of slurry pollution, but this research looks for the first time at the wider risks across the whole UK sector – in particular the vast land take for feed production.” He added that the findings show the need for nutrient management action plans and reforms to permitting regimes, with support from both government and industry to help farmers transition to a less polluting system that protects water quality and biodiversity. An Environment Department (Defra) spokesperson said: “We share the public’s concern about the health of our waterways and are committed to cleaning up our rivers and cutting down on agricultural pollution.”