There are five major breeds of pig used on commercial pig units around the world, with commercial cross breeds /hybrids of these five being the main types of pig that you'll find, either indoors or in the field.
Whilst the so-called 'rare breeds' (particularly the Berkshire and Gloucester Old Spot) have their place on specialty units, supplying premium markets, they suffer from lower growth rates, poorer carcass conformation (i.e. fewer of the cuts that the consumer wants, and proportionally more of those that are more difficult to sell), and are generally less prolific. In short they produce too few pigs per year, which in turn grow too slowly, too fat and at too great a feed cost. Which should draw us to the reasons why the big five are so widely employed - they are prolific, grow quickly and economically, and produce bodies that the processor and consumer want. Let's look at the key points of each.
Originally from the Yorkshire breed, and first recognised in the 1860's, the Large White has proved itself as the basis for many of the commercial hybrids on the market today. This pig has erect ears, a slightly dished face, long back, and big hams. Hardy, and adaptable, they works well in either indoor or outdoor systems. The Large White pig makes an excellent terminal sire (the boar used to produce the slaughter generation on the farm) - put this boar on any sow and you'll see dad clearly in the offspring's conformation and growth rates. This is the principle meat-producing boar used in the UK and many other countries around the world.
Originally imported into the UK in 1949, from Sweden, the Landrace is now one of the most popular breeds in the country. In fact, they go further than these shores - 90% of hybrid gilts produced in Europe and the US contain Landrace bloodlines. The Landrace pig is a lop eared breed, with a long back and large hams - an excellent pig for both butcher and processor (e.g. Bacon production). The breed is versatile - performing well indoors or out, and makes an excellent mother, being docile and able to rear large strong litters.
The Duroc, a large ginger/orange coloured animal with slightly lopped ears was developed in the United States from a 'Red Pig' originally from UK. The breed was named after a Race Horse in the US, famous in the 1820's. An ideal outdoor pig, and extensively used in outdoor hybrids, it has long hair which moults in summer. The Duroc makes a good mother and is known for being very docile. As a terminal sire the boar produces heavily muscled finishing pigs, the succulent meat displaying good 'marbling' (intramuscular fat).
One of the most important breeds in the world is the Hampshire, developed in the USA, where it was first imported to USA in 1832 from Wessex. A black, prick eared high-lean pig with a pink 'belt' around its shoulders, the Hampshire was reintroduced to UK in 1968. It is the principle terminal sire in the USA.
Named after the Belgian village where they originated, the Pietrain came to the notice of a larger marketplace in the early 50's. It is an erect eared breed, mostly pink, with several black blotches over its body. The Pietrain is now the most popular terminal sire in Germany and Spain - Europe's biggest consumers of pigmeat with two of the largest national herds. The Pietrain has a very high lean meat yield, including 'double-muscled' hams, but is very highly prone to stress (a genetic problem leading to meat quality issues as well as problems on farm, which is now being bred out in the latest generations of the breed). In the UK it is used mainly for the production of hybrid pigs.
Andrew is a qualified teacher of English as a foreign language (TEFL), a farmer with twenty years agricultural experience, and worked for fifteen years in the global automotive industry.