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Veterinary surveillance: Pigs

Photo of a pigThis page gives an introduction to pig farming in the UK and how we look out for diseases of pigs. It has links to other pages on the Defra website. You can find further information on other websites by following the link at the bottom of this page.

Pig farming in the UK

Pigs in the UK are used for producing pork, ham and bacon. Most of the pig farms are down the Eastern side of Scotland and England, mainly because that is where most of the cereals for feeding the pigs are grown. There are also some concentrations of pigs in North West and South West England and in Northern Ireland.

Some pig farmers may breed and rear their own pigs right through to slaughter. Other farmers may buy in young pigs (‘weaners’) from breeder farms and fatten them (‘finishers’). The majority of commercial pig farmers buy their replacement sows and boars from specialist units, called ‘multipliers’. These farms produce crossbred animals which produce young piglets which grow very well. There are fewer multiplier farms than commercial pig farms. The multipliers buy their purebred sows and boars from ‘nucleus’herds. There are even fewer of these herds. For this reason the pig industry is said to operate as a ‘pyramid structure’ with large numbers of commercial pig farms at the foot of the pyramid and much smaller numbers of nucleus herds at the top.

The majority of pigs reared for meat in the UK are crossbreeds as described above. However the old traditional breeds still remain. The work of the Rare Breeds Survival Trust helps to support those breeds in danger of disappearing.

In the UK in 2004 we ate approximately 1,500,000 tons of pig meat. We imported almost 800,000 tons of this, as pork, bacon and salami, from other countries; in particular from the Netherlands and Denmark. We export very little pig meat.

How many pigs are there in the UK?

Pigs in a fieldAltogether there are about 5 million pigs in the UK. There are around 500,000 breeding pigs and the remainder are for finishing. The number of pigs in the UK has been steadily decreasing over the past few years. However the average number of pigs kept on one farm has increased.

Everyone who keeps pigs must be either registered with Defra or the appropriate devolved administration. All pigs over one year old which move from the farm and all pigs under one year old going to the slaughterhouse must be identified. This can be by a slapmark on the shoulders, an eartag or an ear tattoo. We also collect information about the numbers and types of pigs during a census of farmers in June every year.

We have separate information for different types of pigs. It is broken down by the weight of the animals, whether or not they are intended for breeding, and whether or not they have had a litter of piglets. As well as the total number in the different countries of the UK, the information can be broken down by county. Records are available for 2005 and from earlier years.

We have used this information to map Adobe acrobat pdf file (548 KB) how many pigs there are in different areas.

Looking for pig diseases

Many people are involved in looking for diseases.

As well as continuous scanning surveillance we carry out regular testing programmes for Brucella suis and Aujeszky’s disease. The results for Great Britain are published each year in the Report of the Chief Veterinary Officer.

Some of the testing is carried out by veterinary officers of the State Veterinary Service (SVS). Meat inspectors of the Meat Hygiene Service look for signs of disease during the postmortem inspection of animals slaughtered for meat. The pig industry has its own scheme for Salmonella monitoring called the Zoonoses Action Plan.

Which are the most important diseases of pigs in the UK?

Different infections and diseases are important to different groups of people. From the point of view of the Government, the most important infectious diseases of pigs present in the UK include salmonella and streptococcal infections and postweaning multisystemic wasting syndrome (PMWS). From the point of view of the farmer, the most important conditions are probably PMWS, porcine reproductive and respiratory syndrome (PRRS), infertility, pneumonia and diarrhoea.

What other diseases do we look out for?

We also keep a look out for pig diseases which do not usually occur in this country. The most important of these exotic diseases is foot and mouth disease. Other important ones are classical swine fever, Aujeszky’s disease and African swine fever. News from other countries about these diseases helps us plan how to keep them out.

Further information


Page last modified: August 28, 2008

Department for Environment, Food and Rural Affairs