OK quick basic primer in transport law.
In England & Wales you would come under one of the Welfare of Animals Transport Orders (WATO) (parallel versions for England & Scotland and Northern Ireland - all 2006 and same for Wales in 2007)
This implements into UK law EU regulation 1/2005, a small regulation of 44 pages!
WATO covers everyone, but exempts some people from most of the regs. In essence
whilst still responsible for the general welfare of your animals, you do not have to complete most of the paperwork.
General guidance on pigs is in the doc below
http://www.defra.gov.uk/publications/files/pb12544d-pigs-080711.pdfFirst exception from the specific rules is if you are not moving animals in connection with an economic activity. Defra have guidance on what they consider economic, and the fact that you are eating your produce seems sufficient to count as economic - see the following general guide, but lack of profit or financial gain don't count.
http://www.defra.gov.uk/publications/files/pb13550-wato-guidance.pdfSecond exemption is under article 1 - which covers farmers transporting their own animals in their own vehicles less than 50km.
Trips to vets are also excluded.
Defra also have an unofficial (non-EU approved) exemption called the single animal exemption that if the number of adults = number of animals being transported up to 4 adults/animals then you are also exempt. This exemption can be withdrawn if abused according to defra. See 1.5/1.6/1.7/1.8 of the WATO guidance document above.
If you aren't in the above, then the rules apply, so we then get 3 types of journey
Under 65km - You must carry an "animal transporter certificate" ATC - the extact form isn't specified, but if you do eaml and answer all the q's, the print will have all the info (and more!) that is needed. The Scottish version also has a proforma that complies with the rules. The existing paper AML also has Section B that is effectively an ATC. You don't have to use any of these forms, but it helps if you do.
You trailer must also be legal (lots of technical bits) including ramps angles - guidance on a legal trailer below
http://archive.defra.gov.uk/foodfarm/farmanimal/welfare/transport/documents/2e-vehicle_spec_other.pdfand lots of various rules on not moving animals of different ages together, near birth etc.
Over 65km and under 8 hours - all the above, plus you must be certified, simple exam 27 multiple choice questions, species specific, so separate exams for pigs, sheep, cattle and poultry.
Over 65km and over 8 hours - you and vehicle must both be certified, and frankly don't go there - if you're planning on moving more than 4 of your own animals over 8 hours, get someone to do it for you, it'll be cheaper !
After that we get to regulations on trailers and what can to towed by what and who - will leave that to another post !