Volume 12: Livestock Farming
11. Other livestock
Relevant aspects of UK pig and poultry production
Structure of the industries
MBM in pig and poultry feed
Pig and poultry waste in cattle feed
Pigs and transmissible spongiform encephalopathies

Structure of the industries

11.13 Pig and poultry production have received less support than other livestock sectors under the CAP. The EU makes no attempt to maintain a particular market price for products from either industry, and there is no intervention buying.

Pig industry

11.14 In 1986, 819,000 breeding pigs were kept on 16,600 holdings in the UK, and 4,794,000 fattening pigs were kept on 16,300 holdings. By 1995 there were 742,000 breeding pigs on 9,700 holdings, and 4,626,000 fattening pigs on 10,300 holdings. ¹

11.15 Pig production occurs in most areas but is prevalent in eastern and northern England to take advantage of cereal production, which forms the basis of pig diets. The cereal diet is supplemented with protein from vegetable and animal sources, including MBM (up until the ban implemented on 29 March 1996), and with minerals and vitamins. Pig producers feed their pigs home-mixed rations prepared on farm or purchased from a feed compounder. Antibiotics are frequently included in commercial pig feed. This, and the high proportion of MBM used before 1996, made pig feed unsuitable for cattle, since cattle will tolerate only a low proportion of MBM in their feed.

11.16 Since the mid-1980s there has been a trend towards concentration of pigs into specialist units and larger herds, separate from other animal rearing systems. For example, the average size of a pig-breeding herd was 49 in 1986, but by 1995 had increased to about 82. ²

11.17 The age at slaughter depends on the type of meat being produced, but can vary from 14 to 18 weeks for lean and tender pork, and from 22 to 34 weeks for bacon, ham and inferior pork. ³ The majority of UK pigs are finished indoors in buildings designed for intensive production, but in recent years outdoor herds have also grown, partly in response to new welfare legislation which prohibits the tethering of sows. The average weight of slaughter pigs has progressively increased over the last decade, which has seen pigmeat production increase accordingly.

Poultry industry

11.18 In 1986 there were 63,296,000 broiler fowls (used for meat production) on 2,000 holdings, and 37,827,000 laying fowls on 44,600 holdings. By 1995 there were 76,577,000 broiler fowls on 2,300 holdings, and 31,507,000 laying fowlson 27,800 holdings. ⁴

11.19 Poultry production has expanded enormously since the 1970s, with an increase in output of over a third between 1975 and 1986. However, as with pig enterprises, the increase in production was achieved with fewer total holdings, indicating greater specialisation and intensification of production processes. ⁵

11.20 A particular feature of the poultry industry, setting it apart from other livestock industries in the UK, is its vertical integration. Around 85 per cent of poultry meat producers and 66 per cent of egg producers are 'integrated'. This means that they control all stages of production from birth to slaughter of broilers or layers, including breeding, fattening, and the production of animal feed fortheir livestock. ⁶

MBM in pig and poultry feed

11.21 An aspect of pig and poultry production particularly relevant to the BSE story is the use of MBM in pig and poultry feed. At the time BSE emerged, pig and poultry feed contained MBM, and the pigs and poultry were exposed to this throughout their whole life span. ⁷

11.22 Indeed, the pig and poultry industries were the major users of MBM in the UK prior to the ruminant feed ban. At the time of the ban's introduction, one MBM supplier estimated that only 12 to 15 per cent of its MBM went into ruminant feed, meaning that 85 per cent went primarily to poultry, and secondly to pig feed. The poultry industry has long been a major user of MBM, because of its high value asa nutrient source. ⁸

11.23 It remained legal to feed ruminant MBM to non-ruminants such as pigs and poultry up to March 1996. Accordingly, compound feed manufacturers supplying cattle, sheep, pig and poultry farms were permitted to use ruminant MBM in compound feed for pigs and poultry. This posed a risk of cross-contamination between batches of compound feed in the manufacturing process at feed mills producing the full range of feeds.

11.24 Consequently, after the ruminant feed ban was imposed in 1988, it was feasible for ruminant MBM to find its way into cattle feed throughcross-contamination at the feed mill, or in transit in the delivery lorry (see vol. 5: Animal Health, 1989-96). ⁹ Cross-contamination with MBM could also occur during preparation and storage of home-mixed rations on farms, in particular where cattle and sheep units were managed alongside pig and poultry units - in 1988 there were 34,421 holdings with both cattle and pigs or poultry, and 23,573 in 1995. ¹⁰

Pig and poultry waste in cattle feed

11.25 A large amount of pig waste from abattoirs entered rendering plants, and was used to produce MBM. The renderers could have responded to the 1988 ruminant feed ban by producing MBM containing porcine material only. Though theoretically possible, this was not done because of the complexity of the task and the difficulty in keeping porcine waste separate from ruminant waste. ¹¹ The inclusion of porcine material in ruminant feed was banned in November 1994, following the implementation of the Spongiform Encephalopathy (Miscellaneous Amendments) Order 1994. ¹²

11.26 At the time BSE emerged, poultry protein - produced in poultry meal production plants as opposed to general rendering plants - was also included in cattle feed in small amounts. The product was derived from material not entering the human food chain, such as heads, feet, manure and the carcass once it had been stripped of meat. ¹³ Another source of poultry protein for use in animal feed was hydrolysed feather meal, produced by chemically converting feathers into a digestible protein form. ¹⁴

11.27 The inclusion of poultry-derived protein in ruminant feed was relatively limited, since MBM was the cheaper option. In theory, this poultry protein can still be fed to ruminants. However, those within the rendering and feed industries suggest its use is virtually non-existent owing to a voluntary ban on using any animal protein in ruminant feed. ¹⁵

Pigs and transmissible spongiform encephalopathies

11.28 Although BSE has never been discovered naturally occurring in pigs in the industry, MAFF reported the successful experimental transmission of BSE to a pig in August 1990 through intracerebral injection. Thus far there have been no reports of pigs having contracted BSE via oral ingestion or by any other non-experimental route of infection (see vol. 2: Science).