Are the Free-living Wild Boar Pure Bred Wild Boar?



Are the free-living wild boar pure-bred or are they hybrids of wild boar and domestic pigs? This question is continually asked and we will attempt to answer it.

Why might they be hybrids?

Some, but not all, wild boar farmers in the UK cross pure wild boar males with domestic pig sows (usually Tamworths) to produce an increase in litter size, from an average of 5 in pure animals to 9 in hybrids. More frequent farrowing, to twice yearly, also occurs. This 'hybrid vigour' obviously makes economic sense. If the free-living wild boar originated from one of these farms then the animals at large might be pure, hybrid or a mixture of both.

Sow with pink nose Purity Warning! A boar farm bred sow with a bit of pink colouration on the end of her nose - this could be indicative of there being some domestic pig genes in her bloodline. Everything else about the sow appears fine. (© Martin Goulding).




How can you tell if the free-living boar are pure?

In a nut shell you can't. There is no biochemical or genetic test commercially available toprove the purity of an animal. Genetic material from one animal can be compared to another and differences in the base pair sequences noted, but this does not tell if one of the animals is pure bred, only that there are differences. The crux of the matter is that it can not be known for certain if so called 'standard' samples of pure wild boar are actually pure. The reason for the doubt is that wild boar have many different sub-species and they have never been properly genetically classified. Classification attempts in the past have been made using craniometrics (skull measurements) and phenotypic appearance (body shape and coat colour). Genetics is only just beginning to be used. However, sorting out the different wild boar subspecies is a nightmare because of:

1. 'Phenotypic plasticity' whereby wild boar populations, genetically the same but in different localities, gradually change in shape and appearance in response to environmental factors.

2. Historical cross-breeding with escaped or free-ranged domestic pigs centuries ago.

3. Recent contamination of pure bred populations from the illegal and legal movement of animals from different countries to re-stock areas where the hunters over did it the year before.

Why not use chromosone numbers?

The French, who take wild boar farming and hunting very seriously as big money is involved, have wrestled with this problem of purity for years. Their solution is to use chromosome numbers, French wild boar have 36 chromosomes and domestic pigs have 38. Hybrids have 37. Therefore an animal that looks like a wild boar but does not have 36 chromosones is not pure. Confirmation of this ruling can be seen at this web address: Chromosomes ruling . The site is in French but can be understood using a web translation service, for example, Altavistas'

Unfortunately things are not so cut and dried as the French would like to believe since wild boar in other parts of Europe can have both 36 and 38 chromosomes (Porter V. (1993) Pigs, A handbook to the breeds of the world, Pub. Helm Information Ltd, Mountfield, UK), but this doesnt seem to bother the French!.

How is purity currently determined (aside from chromosome numbers)?

Purity is judged on the animals shape and appearance: Below are listed the typicalcharacteristics of a pure wild boar and a hybrid (sourced from French wild boarfarming guidelines: Pinet J. (1990) Cerf, Daim, Sanglier Analyse strategique de la filierevenaison

Pure wild boar characteristics:

Head is narrow with a straight profileSnout is narrow, straight and long
Muzzle is always blackEars are pointed and held erect
Tail is straight with long tassels at the endHind quarters are sloped and the shoulders (in males) are large
Body weight lies forwardLegs are long
Coat colour is brindled and an underlying brown pelage is presentPiglets have brown and cream stripes

Sow with pink patch Purity Warning! Pink colouration on the rear inner thigh of this farmed boar may also be indicative of there being some domestic pig contamination. Again, everything else about the sow appears fine. (© Martin Goulding).





Hybrid characteristics:

Head is broad with a concave profileThe snout is short
Muzzle is often marked with pinkEars are broad and slightly pendulous
Tail more or less corkscrewCoat splashed with white
Light coloured hoovesUpper line of body straight
Young with only faint stripes

To the untrained eye these differences are not that easy to spot, especially if the animal contains only a bit ofdomestic blood. However, to simplify, definite no-no's which indicate hybridisation are:

'orrible sow Purity Warning! Although this farm sow has the right coloured coat, the shape is all wrong - her face is too squash and her body is too fat and barrel shaped - more like a domestic pigs. (© Martin Goulding).




Floppy ears.     Pink noses or feet.    Curly tails.    White socks.    White areas on body.
Spots, saddles or other splodges of colours in the coat.    Dished nose.

Where do the free-living UK boar fit in with this scheme.

No UK boar have been reported with any characteristics that could be associated with being hybrids except that a pale-coated variety exists in the East Sussex population. These animals have no other characteristics to imply that they are hybrids and the pale coats may be a natural variation, as wild boar coat colours do vary - we just don't know.

Sow with good profile A free-living English wild boar sow in summer coat highlighting important purity characteristic of a long straight snout. (© Martin Goulding).



Does it matter if there is some domestic blood in the UK boar?

It all boils down to personal taste. If they look and act like like wild boar then probably not, unless you are a purist. Considering many populations on the continent are not pure, maybe we should not get to hung up about purity, provided our boar don't start developing multi-coloured coats, floppy ears, curly tails....

A useful working definition is that if it looks like a wild boar, acts like a wild boar, and fills the ecologial niche of a wild boar, then it is a wild boar

If you know any different, or have seen an unusual shaped/coloured wild boar in Britain, please tell us. We are willing to stand corrected.

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