Pigs

A Guide to Management - Second Edition

Neville Beynon

• Editore: Crowood
• Anno: 2014
• ISBN:
  9781847977533
• Argomento: Technology & Engineering
• Categoria: Animal Husbandry

Pigs - A guide to Management - Second Edition provides a comprehensive introduction to all aspects of pig-keeping: how pigs have developed, the influence of the market on the breeds and pig-keeping systems, nutrition, the pig and its environment, reproduction, piglet birth, survival, growth and development, and the important place of artificial insemination in both modern commercial production and maintaining our rare breeds. The welfare, care and managemet of the pig through to its sale as a finished pig, along with that of the breeding sow, gilt, boar, is a central theme. Covers all aspects of pig husbandry and provides a comprehensive guide to developing pig management skills and illustrates the range of pedigree and commercial pig breeds and how they are influenced by the market. Fully illustrated with over 120 colour photographs including the current BPA-registered pig breeds.

1

The Pig and its Development

Pigs have been a feature of farms in Britain since the early Neolithic period. It is highly likely that the wild pigs of Europe and their partially domesticated cousins followed our Neolithic forefathers into the first farming villages. The pigs’ scavenging and rooting behaviour was both a help and a hindrance to these early people, and they demanded control and management. Economic pressures and developments have influenced the way in which pigs have been managed ever since these early times.

The modern domestic pig (Sus domesticus) and its proud and potentially ferocious cousin, the wild boar (Sus scrofa), both belong to the pig family (Suidae). This curious and yet fascinating mammal developed over the past 50 million years from the same type of usually even-toed animal of the order Artiodactyla. It is now known that the pig group (Suina) sub-order had already split from the camel and ruminant sub-orders by about 46 million years ago.

It is a curiosity of evolution that the pig family maintained or developed a less complex digestive system, rather similar to our own in outline, with the ability to eat food based on both plants and animals. The recent reading of the pig’s genome (genetic code) confirms that the pig has retained genes influencing this ability, and that these genes are similar to those found in our own human genome. The wild boar is frequently described as the ‘savage forest omnivore’: it is known to eat carrion, and to catch and eat rabbits and other rodents, snakes and insects, as well as using its highly developed sense of smell to locate roots and other easily digestible vegetable matter, including nuts, seeds and truffles. It is now known that pigs are genetically programmed to have a sense of smell superior to most other animals, and that these genes are continuing to change and evolve.

It is also known that they have significantly fewer bitter taste receptor genes than humans, as well as those that produce a different perception of what is sweet or ‘meaty’ – although piglets certainly appear to have a sweet tooth. Unfortunately they also have a high tolerance for things containing a lot of salt, and this can be extremely dangerous. Nevertheless, this has led to an ability to consume a range of food sources well beyond the taste range of the human omnivore, and the pig has made good use of this, despite an inability to utilize high-fibre diets as efficiently as ruminants.

Man, the hunter gatherer, must have eaten various forms of wild pig from earliest times. Cave paintings and the discovery of pig bones testify to this. The exact timing and method of the pig’s domestication is becoming easier to explain now that we have been able to read the pig’s genetic code. Supporting archaeological evidence indicates that domestication may have actually preceded crop growing.

There is also very strong evidence that domestication occurred in places such as China and Europe independently and at about the same time. Until now, there was a considerable problem in obtaining knowledge of the true descent of the domestic pig, let alone the origin of the numerous breeds that have evolved as recently as the past few centuries. The highly adaptable pig probably saw its chance some eight to twelve thousand years ago, and it is now evident that this may have been sometime before our Neolithic ancestors began to farm crops. The arrival of the village settlements in a forest clearing probably provided the ideal conditions for pigs, with their omnivorous eating habits. Acting the role of scavenger, the pig became the refuse collector of old. Some researchers believe the pioneering pig also played a significant role in clearing the forests and preparing them for pasture suitable for farming sheep and other grazing animals.

European wild boar, Sus scrofa – telephoto of a shy lone male in a central European forest in 2013.

Domestication may have evolved over four stages. First contact might have been brought about by the pigs’ inquisitive scavenging habits and by living close to humans in early settlements. The twenty-first-century citizens of Berlin, Germany, can testify to this, with around 8,000 wild boar living within the city limits in small woodland pockets. They would certainly have found it advantageous to live close to man’s new-found village-based food-production industry we now call farming. The second stage may have involved some containment and control of the troublesome pig in order for it to provide useful products. The third stage might have involved the beginnings of husbandry and selection for valued characteristics – for example, wild stock may have been used to breed for size or some other economically important characteristic. By the fourth stage, the wild pig would no longer have contributed to the types that developed into the European and Asian domesticated pigs (Sus scrofa palustris and Sus vittatus), although it is now known that their genes have had a significant role to play in modern pig breeds. Pigs the exploiters had become the exploited.

It is probable that the Chinese were the earliest pig farmers in the modern sense. Excavations at Zengpiyan, Guilin and Guangxi Zhuang confirmed that pig farming existed there 10,000 years ago. They have had a major influence on the development of pig breeds worldwide, and their breeds, based on the Asian wild pig (Sus orisatus) and the sunda pig (Sus vittatus), have developed in a unique and diverse style, with some fascinating physical characteristics. The Pig Genome project has also shown that the European wild pig and the Asian wild pig developed separately for about a million years and almost became distinct species. This has all probably added to the tremendous diversity found in the pig’s genetic make-up, and in turn the significant variation we find in the 250 or so pig breeds found worldwide.

Pig meat was, and continues to be, the most versatile of meats. As with his cousin the wild boar, the meat, fat, hair, hide, teeth and bones of the domesticated pig provided these early farmers with food, clothing, furniture, decoration, and fat for candles and lamps. Various offals may also have been used for primitive medicines. Insulin (now also synthetically produced), skin graft material and heart valves are just a few modern examples. Archaeologists have linked the presence of large collections of pig bones at Neolithic burial mounds in the UK and Europe (barrows and longmounds) with feasting and high social status settlements. There is little doubt that the pig played a significant and perhaps formerly underestimated part in the social foundations of prehistoric Britain. The pig became important in Britain during the Saxon-Norman period, when poor peasant villages clubbed together to pay for a swineherd. The social status of the swineherd in charge of the domestic pig was never high, and yet, paradoxically, the wild boar was, and is, respected in Europe as the ultimate hunt for the aristocracy.

The pig reached its peak around the Norman Conquest, and then declined due to the restriction on pannage, gradual loss of forests and the rise in importance of sheep. This led to changes in pig husbandry and urged the development of alternatives to grazing acorns and beech mast to systems based on cereals and pulses (peas and beans being fed). These were, and continue to be, expensive commodities, and an imbalance in supply and demand, often caused by harvest failures, meant that pigs were often uneconomical. They began to be housed for longer periods, often on a one per household basis, being fed predominantly on kitchen waste, and this is probably when improvement in pig type began to take place. The traditional swineherd’s medieval pig was a lanky, coarse, long-legged and hairy animal, and had features in common with his cousin the wild boar, from whom he was certainly derived. The housed pig was smaller and fatter, similar to the Chinese types.

This suggests that two distinct types of pig existed for many centuries in varying numbers, side by side, and that they were kept in different husbandry systems. There were, of course, considerable regional variations, and the maintenance of pannage rights in areas such as the New Forest helped perpetuate a strain of pig that had the constitution to forage for mast in the forest. In other areas, brewery or dairy by-products led to intensive pig production. In the eighteenth and nineteenth centuries industrial food manufacturers were buying young store pigs in their thousands and droving them to London to fatten them on starch by-products. Thriving droving industries developed; for example, Welsh drovers linked with the dairy regions of Wiltshire, Gloucestershire and Cheshire, and some of these pigs were grown on to produce ‘Wiltshire Cure’ bacon, considered the best in the country. The economic survival of the Welsh store pig producer therefore depended on the drover, and this interdependence of the weaner producer and his customer, the grower and finisher of slaughter pigs, with the location of slaughter outlets, continues to influence the structure of the pig industry to this day.

The world’s heaviest pig at 1,222kg in 1986, in Taiwan. PIG INTERNATIONAL

The seventeenth century saw the introduction and influence of Chinese and Neapolitan pigs. These were smaller and matured earlier than the Old English types, and the breeding fashion during the midnineteenth century led to the extinction of many of the larger breeds in favour of these early maturing types. The old large breeds had been recorded as growing to a massive three-quarters of a ton at two years of age, and had apparently been used exclusively for bacon production.

There were many theories about the true descent of most modern breeds. Until the recent reading of the pig genome there was very little evidence to support them. It is, however, possible to trace the emergence of the Yorkshire breed, which probably, by varying degrees of Chinese influence, developed into the Large White Yorkshire and Small White Yorkshire breeds; these were crossed in turn, and produced the Middle White breed. Certainly at the Royal Show in Birmingham in 1876 there were three distinct categories of the Yorkshire breed of White pig. We can probably thank the apparent love of Yorkshire folk for a monster pig such as the Old Yorkshire, whose genes were maintained in good measure in the Large White breed. That said, the pig genome project confirms that of the twenty-one thousand pig genes that encode protein growth and development, more than a third of them in all UK pig breeds have come from the Asian pigs that were first brought in less than 200 years ago.

As a pure breed, the Large White is probably the most important in the world (especially when the related USA Yorkshire breed is included), though we cannot thank the British farmer for this. The pioneer breeder of Yorkshires, and more specifically the Large White, was a weaver from Keighley, named Joseph Tuley. Apparently such smallscale pig keepers had an enthusiasm for improving pigs matched only by their love of pigeons and greyhound dogs. According to the Journal of the Royal Agricultural Society of 1881, by 1850 they had produced a far more refined animal than the coarse mammoth formerly seen in our show yards and now found upon some northern farms.

Unfortunately for many of the larger breeds, the show ring was working against them. The farmer breeders’ obsession with fat production, and the smaller cuts demanded by the increasingly affluent consumers, led to a period in British pig breeding which, in retrospect, was clearly based on the wrong priorities and lost opportunities (Julian Wiseman, see Further Reading). The London trade demanded a small pork pig of 40 to 70lb (31kg) carcase weight, with no more than 1¼ in (32mm) of fat, whereas the industrial regions, and particularly Birmingham, demanded larger pigs of up to 350lb (155kg); it is interesting to note that the Midlands slaughter weight remained significantly heavier until relatively recently. Apparently, those involved in manual labour and those whose work demanded the consumption of a cold meal preferred larger cuts of meat from heavier pigs. The cottager’s pig was often slaughtered at these heavy weights.

Also the development of bacon curing, based on very highly salted meat, was no longer confined to the cold months of the year, and should have inspired the breeders to produce larger, leaner pigs. This was because George Harris of Calne, in Wiltshire, had discovered an American curing process that could be carried out throughout the summer using an ice-cooled house. In 1864, together with his brother Thomas, he patented and perfected a mild cure (Wiltshire Cure) which did not require a large fat covering to take up the salt essential in hard-salt (dry) cure.

Wiltshire sides of bacon cured on the farm in an outhouse.

But the breeders, for some reason, probably associated with the ‘fancy’ of the show ring, applied the wrong priorities, and lost opportunities that were staring them in the face. Neither pork nor bacon production required fat pigs, yet the breeders continued to consider a good ‘breeding pig’ to be essentially fat. Charles Spencer stated c. 1880 that the sheep judges had the additional responsibi...