Postweaning multisystemic wasting syndrome (PMWS) was initially described in 1991 in Saskatchewan (Canada) and has now been described in all continents rearing pigs but Oceania. Porcine circovirus type 2 (PCV2) is the aetiology of this disease, which has also been called porcine circovirosis in some countries. Although the full spectrum of clinical signs and lesions observed in natural cases of PMWS is very difficult to reproduce under experimental infections using PCV2 alone, little doubt exists on the causal relationship between the virus and the wasting syndrome. Furthermore, the clinical and pathological scope of PCV2 infection has been expanded since 1991, and it has been implicated in other conditions: reproductive disorders, porcine dermatitis and nephropathy syndrome (PDNS), the so-called porcine respiratory disease complex (PRDC), proliferative and necrotising pneumonia (PNP), and congenital tremors. The role of PCV2 in these conditions has not been fully clarified and, in some of these cases, it remains as a controversial issue. The objective of this presentation is to review some practical aspects of PMWS.

The increasing prevalence of PMWS /PDNS within global pig production since 1995 has steadily increased, UK first affected in 1999. Impact on post weaning mortality is variable with rates exceeding 30% commonly reported, no medication or treatments have proved effective or successful, vaccination is still unavailable and the industry is still striving to find the scientific answers and solutions behind this economically damaging disease. Porcine Circovirus 2 (PCV2) is widely acknowledged as the probable causal agent but still not confirmed, if so has it changed or is it a new PCV? With enhanced virulence, a definitive identification and test is urgently required. The objective is to demonstrate how successful specialised management techniques alongside a batch system is capable of reducing post-weaning mortality to pre PMWS levels and to further improve overall herd health, productivity and economic performance.

The high yields obtained in agriculture rely heavily on the use of domesticated and genetically improved breeds and varieties. Until quite recently this has not been the case for most farmed aquaculture species that, in the genetic sense, are still much closer to the wild state than are the major terrestrial animals and food crops. Less than 10 % of the total world aquaculture production is based on improved strains. Due to a growing human population and a decline in production from capture fisheries, there is therefore a great disparity between the need for increased aquaculture production and the genetic quality of the strains available to meet that need. Moreover, full benefits of investments in management improvements (feed and feeding practices, control of diseases, etc.) can only be obtained through the use of genetically improved animals.

Aquaculture is a rapidly expanding and extremely diverse form of animal production. Aquaculture takes place in systems that cover an enormous range of levels of intensification from extensively managed low input static ponds to super-intensive high exchange rate silos with liquid oxygen injection. Appropriate nutritional strategies are required for each level of intensification.

The management of disease in fish presents many challenges which are not usually encountered in terrestrial animals. The aquaculture environment poses severe limitations on general observation, examination, disease prevention and treatment. Aquaculture has been described as ‘three dimensional farming’ with recognition of health problems often reliant on surface observation, although the use of remote control camera systems is increasing. The ability to carry out adequate observation may be restricted by poor access or adverse weather.

The intestinal microflora are an integral part of the digestive system of all animals. Bacteria in the gastrointestinal tract derive most of their energy for reproduction and growth from dietary compounds, which are either resistant to attack by digestive fluids or absorbed so slowly that bacteria can successfully compete for them. Since bacterial species differ from each other in relation to their substrate preferences and growth requirements, the chemical composition and structure of the digesta largely determines the species distribution of the microbial community in the gastrointestinal tract. As a consequence, bacterial community structure is very much dependent upon the diet as the ultimate source of substrates for metabolism.

In the natural situation, the piglet’s transition from a wholly milk to a wholly non-milk diet (weaning) is gradual and paralleled by progressive, appropriate modification of gut structure. The sow’s milk provides nutritional, trophic and immune support throughout this transition thereby mediating intestinal exposure to novel nutrients and pathogenic agents whilst the gut structures necessary to process them appropriately are maintained and developed. Commercial weaning deprives the piglet of lactogenic support and simultaneously necessitates the marked acceleration of gut development if piglet health and growth are to be maintained. Intestinal mass, growth (Slade and Miller 2000) and fractional protein synthesis rate (Ks) increase significantly following weaning (Le Dividich and Seve 2000). Correspondingly, the nutrient cost of post-weaning intestinal development is high. However, weaning is invariably associated with a dramatic reduction in feed intake and, in turn, with a decline in gut efficiency characterised by a reduction in villus height and an increase in crypt depth. Perversely, the gut morphology of the weaner thus appears a limiting factor in its own development. Here we introduce a simple histological method for estimation of individual crypt-villus structure surface area and then, in conjunction with conventional histomorphological measurements, use this to relate piglet performance, nutrition and gut morphology.

Dietary carbohydrates constitute a major fraction of the diets for pigs. The carbohydrate fraction consists of mono-, di- and oligosaccharides and two broad classes of polysaccharides – starch and non-starch polysaccharides (NSP). The carbohydrate fraction has a diverse composition in terms of constituent sugars (pentoses, hexoses, deoxysugars, etc.), glycosidic linkages (alfa or beta), size (degree of polymerisation from one to several thousand), and physical form (soluble in water, insoluble, cation and adsorbing properties). It is now evidential clear that the composition of the carbohydrate fraction influences the digestion and absorption processes of carbohydrates and other nutrients in the various parts of the gastrointestinal tract, it has a profound influence on the secretory response of the gut to feed intake, the volume flow, the mucosal architecture, the composition of the gut flora and the development of the gastrointestinal tract.

The overall title for these sessions is “Reconnecting the food chain linking farmers scientists and consumers”. Reconnecting the food supply chain was probably the strongest single message to come from the UK Government’s Policy Commission on the Future of Food and Farming (Anon., 2002). Progress on the Policy Commission’s recommendation to establish a Food Chain Centre will no doubt be reported by Dr Segal from DEFRA. The real task of linking farmers, scientists and consumers, however, cannot be accomplished by Government. It is not sensible to expect Government to take on such a role: have we not all got voices?

Consumers’ Association (CA) campaigns on behalf of all UK consumers. CA is a not-for-profit organisation, funded through the sale of our Which? range of consumer information and products. We are founder members of BEUC, the European consumer organisation and Consumers International (CI), the international federation of consumer organisations.

Food has always been one of our main campaigning areas because it is so central to people’s lives. We have been key players in debates around food policy over the last twenty years and successfully campaigned for the establishment of the Food Standards Agency, following a succession of food scares and a breakdown in consumer confidence in the way that food issues were handled. The over-arching aim of our food campaign is ‘for all consumers to have access to food that is safe, nutritious of good quality and affordable, and to make healthy lifestyle and informed food choices.’ Our current campaigns, focusing on areas where we consider there to be significant consumer detriment, include: food labelling and claims, genetically modified foods, prior approval of food premises in order to help reduce food poisoning, and meat safety.

Government, supermarkets, consumers, farming leaders and opinion formers all have a clear view of what primary producers and landowners should deliver in terms of the economic and environmental goods needed to maintain a sustainable, accessible and visually attractive countryside. The trouble is that while each may have a clear vision, it is not always the same vision.

The key communication chains in the industry are between farmer-market-farmer; between farmer-taxpayer/consumer-farmer; between farmer-scientist-farmer and between farmer-government-farmer.

Genetic variation in physiological regulation has been studied in humans to explain disposition to hereditary metabolic diseases, such as diabetes, dwarfism and acromegaly. In farm animals the aim of such studies has more often focused on understanding individual variation with a view to develop physiologically based indicator traits that could help speed up genetic improvement programmes. To be efficient, any indicator trait needs to be measurable both early in life and in animals of both sexes. The advent of molecular or DNA based genetic markers has presented us with an alternative set of indicator traits. These may be seen both as competitive traits and as traits, which can be used in combination with physiological indicators.

Extensively managed grassland (predominantly hill and upland) represents three quarters of the total land area converted to organic production in the UK. This has occurred because of the availability of conversion aid payments, the downturn in conventional lamb prices towards the end of the 1990’s, and a perception that hill and upland farming is already part way towards organic. Organic farming is further encouraged through the Hill Farming Allowance (HFA) scheme, which provides a 10% enhancement for organic production.

According to the EC Regulation 1804/99, health and welfare of organic livestock should be promoted primarily by preventive measures using appropriate breeds, feeds and feeding practices and husbandry techniques for the species in question and by implementing stable social conditions for breeding animals (CEC, 1999). Whilst the EC Regulation on organic livestock production came into force fairly recently in August 2000 and has hardly had a chance to have an impact on existing organic production systems, there is a growing body of epidemiological evidence on the impact of organic management on the health and welfare of livestock. Furthermore, a three-year networking project, the Network for Animal Health and Welfare in Organic Agriculture (NAHWOA), between 17 institutes from 13 different EU countries has recently published their conclusions and recommendations on animal health and welfare in organic production systems (Anon, 2002). A recent review of literature (Hovi et al., in press) and the NAHWOA conclusions suggest that animal health situation in organic livestock systems is similar to that found in conventional systems. Some differences in the prevalence of different conditions exist. A typical example of higher dry period but lower lactation period levels of mastitis in organic than in conventional systems is presented in Figure 1. It has been suggested that the minimal organic standards and their implementation via certification procedure are likely to provide several preconditions for good living conditions for farm animals (Sundrum, 2001), and the NAHWOA concludes that the current evidence supports the claim that organic livestock production often provides better welfare than conventional production systems, particularly by providing more freedom for species-specific behaviour for livestock. It has, however, been suggested that the organic standards do not necessarily provide a balanced approach to animal welfare and that some conflicts between welfare aims and other organic farming objectives may exist (Anon, 2002). An example of how experts perceive the impact of organic standards on animal welfare is given in Figure 2.

Endoparasite control in organic and non organic livestock shares many features. The difference is that organic farmers are constrained by the requirements of the standards which regulate organic production (UKROFS, 2001). This paper reviews the alternative strategies currently available.

Knowledge of manure composition is important for farm nutrient management, either if importing manure onto a farm or transferring nutrients around the farm in ‘home produced’ manures. Many factors affect the nutrient content of the manure ready to spread onto the land (Smith & Frost, 2000): dietary input and quality, nutrient losses during housing and storage and additions of bedding material and/or water. There are many reports of average values for manures from conventionally raised livestock (e.g. Anon., 2000 for the U.K.). However, there are less data available for manures produced on organic holdings. It is probable that composition will differ from conventionally produced manures because of differences in diet and manure storage methods (composting and/or long-term storage). Therefore, we aimed to test this under U.K. conditions by analysing cattle manures from organic holdings for comparison with data on conventionally produced manures.

During the last decade, many of the developed countries have seen a rapid move toward explicit farm animal welfare standards. Three historical developments during the last half century have contributed to this move: (1) the emergence of intensive animal production systems developed on the principle of maximizing production efficiency, (2) the perception (sometimes justified, sometimes not) that animal production is becoming an industrial, technological activity substantially controlled by corporate owners, and (3) a rapid increase in humanitarian attitudes toward animals.

The rapid increase in the production and consumption of livestock and livestock products fuelled by population growth, urbanisation and increase in average per capita income has come to be known as the livestock revolution (Delgado et al 1999). A rapid growth in per capita consumption of livestock products in developing countries over the last decade (FOASTAT, 2002)

Livestock production is inherently ‘leaky’ with materials moving from the farming system into waters and the atmosphere as part of the biogeochemical cycling processes that occur in all ecosystems. Increasingly, there are national and international legislative pressures to minimise fluxes of environmentally active materials into waters and the atmosphere. Public opinion is also demanding that the husbandry and management of livestock production is adjusted to take account of the short and the long term impacts on environmental quality. Although livestock farms may be responsible for point source effects these have diminished over recent years and the greater concern is with diffuse pollution effects.

Although methane production from enteric fermentation in ruminants has been studied for many years, it is only recently that research has focused on reducing methane production in order to reduce greenhouse gas emissions. Many new and novel strategies are being researched, but this paper focuses on mitigation strategies that could currently be implemented from the knowledge already available.