Laying hens are highly cost-effective producers of polyclonal antibodies in comparison with mammals as the antibodies can be purified from egg yolk. The antibodies are called IgY to differentiate them from mammalian IgG antibodies. Avian antibodies represent both a reduction and refinement in animal use. The cost for producing IgY is lower than for mammalian antibodies as chicken housing is cheap and the isolation/separation process is economical, high yielding, uncomplicated and fast.

IgY antibodies do not cross-react with Fc receptors, mammalian immunoglobulins such as RF and HAMA or activate the complement system and thereby reducing the cause of false positive results in immunological assays. These properties have also made them attractive for peroral immunotherapy for a variety of gastrointestinal diseases, such as human rotaviruses, enterotoxigenic Escherichia coli and Salmonella spp. In the future the IgY technology offers great opportunities to be more widely used in immunotherapy, diagnostics and research.

Force-feeding is a very old practice, first recorded in ancient Egypt, but until the 1950's foie gras production remained somewhat limited in volume. Foie gras is currently produced in various countries but approximately 80% of world production and consumption takes place in France.

Geese, which were the most common specie been force-fed until recently, now account for less than 10% of the total world foie gras production. Ducks such as the Muscovy duck (Cairina moschata) account for less than 5%, and mule ducks for the rest. Thus, over 35 million mule ducks were force-fed in France in 2001, accounting for nearly 95% of the domestic foie gras production. This increase was made possible by technical progress in specific breeding programmes and force-feeding practice.

However, the future of this production is uncertain, at least in Europe. Indeed, although a number of experimental approaches have shown that there is no scientific evidence that validates such adverse comment, this procedure is highly criticised in terms of animal welfare. The Council of Europe therefore adopted two specific recommendations in 1999 and although its practice is not banned at present, it is limited to the areas where it is already practised and only under specific rearing conditions. Therefore, the question is: will it be still possible to produce foie gras in France or elsewhere in Europe in the future and, if not, where and how will it be produced?

The Protocol on Animal Welfare annexed to the EC Treaty in 1999 obliges the European Institutions to fully consider animal welfare in the drafting and implementation of Community legislation. The reform of the common agricultural policies (CAP) foreseen by Agenda 2000 follows the trend of more market oriented measures decoupling subsidies from production. Farming is seen as fundamental to other key societal goals such as food safety and quality, animal welfare, rural development, sustainability etc.

Over the years, recommendations of the Council of Europe and EU Directives specifically concerning farm animal welfare were developed and these are becoming increasingly stringent. European regulations relevant for poultry include Directives on the housing of laying hens, transport and slaughter.

Recently, the World Organisation for Animal Health (OIE) identified animal welfare as a high priority for the coming years. Actions include the development of internationally applicable guiding principles and standards for good animal welfare practice.

Animal welfare is an issue of increasing significance for European consumers and citizens. Since the consumer is the end-user, his or her requirements form the bottom-line for any effort intended to achieve the ultimate fine-tuning necessary to assure societal and economic sustainability of agri- and food-chains (‘from farn to fork’). This means that efforts to inform the consumers and to address their concerns about animal welfare need to be at the forefront of policy and industry agendas.

The control of excreta/litter moisture and quality is a priority in the modern poultry industry, to avoid environmental and animal welfare problems and to reduce productivity losses. Control implies the reduction of their amounts and moisture content. Several factors can affect them, some related to management and housing, others related to diseases and finally, dietary factors. The paper reviews some nutritional aspects that could interfere with the moisture and quality of poultry excreta/litter, focusing on dietary factors affecting water consumption, water excretion and the amount and composition of excreta: dietary protein level, electrolyte balance, ionophores, cereals causing viscosity problems or containing high levels of non-digestible fibre fractions, unusual ingredients or by-products and finally some feed technological treatments.

Avian embryos develop within the confines of an eggshell independent of maternal physiological functions. The eggshell provides not only an airway for diffusive gas exchange of the embryo, but also a wide space available for measurements of physiological functions and makes it possible to regulate directly external nvironments for physiological study. Firstly, in materials and methods section are shown measurements of various cardiogenic and electrical signals while maintaining dequate gas exchange through the eggshell. Secondly, the report summarizes mainly our studies on embryonic gas exchange and measurements of circulatory variables with an emphasis on the embryonic heart rate which we measured taking advantage of the hard eggshell. Lastly, development of thermoregulatory competence in avian embryos is briefly summarized.

A comparative study was undertaken on the performance of Khaki Campbell, Desi ducks and their reciprocal crosses in the Darrang District of Assam (India). Four hundred and seventy ducks were studied for certain economic traits. Results of the study in respect of age at maturity, body weight, egg production, egg quality, mortality and economic performance from the flocks are highlighted.

Bacteria in nature appear as diverse communities, which may comprise of hundreds of different species. The shared capacity of the bacterial communities to adapt in any imaginable set of conditions is remarkable. Many bacteria have growth requirements, as yet undiscovered, which are fulfilled by their natural habitats. Indeed, bacterial communities have members specialized on different functions and providing vital elements to other bacteria living in the same community. Therefore, most bacteria cannot easily be isolated from their habitats by the routine culturing methods used in most laboratories today. To overcome the difficulties in culturing of individual microbes, modern approaches analyse the structure of bacterial communities by determining the characteristic features of the microbial DNA extracted from the community samples. Using such techniques we have found that 90% of the bacteria in the chicken gastrointestinal tract represent previously unknown species. Furthermore, more than half of the 640 different species found represent previously unknown bacterial genera. Bacteria in the gastrointestinal tract derive most of their carbon and energy from dietary compounds which are either resistant to attack by digestive fluids or absorbed so slowly by the host that bacteria can successfully compete for them. The performance improvements on use of a growth promoting feed antibiotic is due to factors such as reduced competition for nutrients in the small intestine, reduced local inflammation due to control of pathogens, and reduced size of intestine. Since bacterial species differ in their substrate preferences and growth requirements, the chemical composition and structure of the digesta largely determines the species distribution of the bacterial community in the gastrointestinal tract. Consequently, it should be possible to shift the microbial community from harmful to non-harmful bacteria by changing the diet.

Reasons for starch digestibility variations are reviewed by considering starch granule structure, antinutritional factors and access problems in coarse particles. Feed technology treatments that can overcome low starch digestibilities are also reviewed. Before considering these factors, the particular features of the digestive system of chickens are briefly reviewed.

The digestive system of chickens for starch hydrolysis is characterised by a high enzymatic potential. However, in contrast with mammals, the potential of chickens for completing starch digestion by microbial degradation in the distal part of the digestive tract is very low.

Variations in starch granule structure especially concern legume seeds compared to cereals, with greater resistance observed for the former. Plant mutants may result in variations in amylose contents of starch granules. Those with high amylose content (70%) produce low starch digestibilities. Cereals with no amylose (waxy starch) do not show strong evidence of benefit despite lower resistance of starch granules.

In practical conditions, antinutritional factors such as proteinaceous α-amylase inhibitors, condensed tannins and viscous water-soluble non-starch polysaccharides generally result in low effects on starch digestibility. However, viscosity may induce a noticeable effect with high viscosity barleys. There is much less evidence that viscosity can explain the low starch digestibilities (<94%) which are observed with some wheat samples. Positive effects of enzyme additives on starch digestibility of cereals probably result from effects both on viscosity and on disruption of coarse particles.

Access problems in coarse particles are responsible for low starch digestibilities observed with legume seeds. However, mechanical treatments such as fine grinding and pelleting can readily overcome this problem. Access problem in coarse particles is also probably the reason that explains low starch digestibilities in some cereal samples, as shown by negative relationships between hardness and starch digestibility of wheats. However, grinding and pelleting of cereals seem to be less efficient than with legume seeds. Interactions with feeding behaviour and genetic origin of birds have also to be considered for explaining variations in starch digestibility of cereals.

Formal knowledge about traditional free-range chicken production in tropical countries is increasing but still limited. However, it appears from literature studied connection with these studies, that management, and thus production performance, in general is comparable in different countries and affected by similar factors. Further, poultry production has shown to be a very important income generating activity, predominantly run by women. On the basis of three studies (A, B and C), the paper describes local chicken production in a communal area of Zimbabwe and highlights production characteristics. Study A is an investigation of the management and production through questionnaires and semi-structured interviews. Study B is a phenotypic description of 360 chickens and a description of feed availability. Study C is records of production during 6 months. Findings confirmed that women owned most chicken flocks and that income generated from chicken production was spent to better nutrition, health and education of the family. High mortality and slow growth were, by farmers perceived to be the major constraints to production. This was supported by production records, which showed that survival among young chickens was low (45% until 16 weeks of age). Most deaths (69%) occurred during the first 3 weeks after hatching. Most common mortality causes were diseases, predation, external parasites and accidents. Few clutches per hen per year with long brooding periods resulted in low production of chickens ready for slaughter or sale. Growth rates until 10 weeks of age were just over 6 g/day. Production results are discussed in relation to other literature.

Poultry carcasses resulting from death by natural occurrences at high levels of production represents a tremendous amount of organic matter that requires environmentally and biologically safe disposal or utilization. Methods for disposal of poultry carcasses include burial, incineration, composting, and rendering. Burial pits used for carcass disposal pose concerns that include the decline in ground water quality where pits are located and residue remaining in pits after years of use. Burial is no longer permitted in some poultry producing areas of the United States except in he case of catastrophic loss. Incineration is a biologically safe method of disposal; however, it tends to be slow and expensive even when highly efficient incinerators are used. Burial and incineration impose environmental concerns that are becoming less acceptable. Research has been conducted during the past decade in support of composting for carcass disposal. When poultry carcass composting is properly conducted, disease-causing microorganisms do not survive the process and the composted material can be used as a soil amendment. Composting is environmentally sound, relatively inexpensive, and has gained widespread acceptance. Rendering carcasses into a protein by-product meal is an alternative in the United States, but is not permitted in the European Union. Poultry carcasses can be removed from the farm, but the spread of pathogenic microorganisms during routine pickup and transportation to a rendering facility may present a substantial threat. Refrigeration, principally freezing, has potential for short-term storage prior to rendering, but costs of operation and transportation need careful consideration. Lactic acid fermentation of poultry carcasses prior to transportation stabilizes carcass deterioration and minimizes pathogen threat. Fermentation allows for longterm on-farm storage of poultry carcasses, reduced transportation costs and results in a usable feed ingredient. When coupled with rendering, fermentation is an excellent alternative for storing and transporting pathogen-free poultry carcasses. All methods that allow for the environmentally safe and bio-secure disposal of poultry carcasses should be considered. No single method will completely solve the problem.

Interactions between nutrition and immunity are diverse and have profound implications on animal growth and productivity. The innate immune system provides protection during the initial stages of infection and is responsible for mediating many of the alterations in nutrient metabolism. The macrophage is the key sensory and regulatory cell of the innate immune system. Their pro-inflammatory cytokines coordinate local immunity to pathogens, yet also act systemically to alter metabolic homeostasis and decrease food intake and growth rate. Altered energy, amino acid, lipid, and mineral metabolism have nutritionally important implications. For example, an innate immune response results in decreased uptake of amino acids by skeletal muscles and a corresponding increase in uptake by the liver and to a lesser extent by leukocytes. The net result is a decrease in amino acid requirements with no change in the efficiency of their use for growth. The shift in the priority of individual tissues for nutrients appears to be accomplished by changes in the types and amounts of their nutrient transporters and storage proteins. Adaptive immune responses result in considerably more subtle changes in nutrient metabolism than innate responses.

Preliminary observations on the socio-economic status of poultry farmers in rural areas in Assam and the demographic distribution of the poultry, indicated that a large section of unemployed youth, landless labour and housewives, earned their livelihood through poultry (broiler) farming. Apart from good quality stock and feed, these farmers were also very enthusiastic to rear their birds in low-cost comfortable housing with optimum stocking density, in order to have a better remuneration for their product. Keeping this in mind, a study was conducted on the effect of different roofing materials (polythene sheet, corrugated iron sheet and thatch) and stocking densities (0.75 and 1.00 sq. ft. per bird) on the performance of broilers in rural conditions in Assam. Results of the study in respect of socioeconomic status of the farmers, demographic distribution and productive performance in terms of body weight, weight gain, feed consumption, feed conversion ratio and mortality and economy are highlighted. A total of 600-day-old commercial broiler chicks, in five groups, were used in the study.

Japanese quail research measured by the number of published papers has gradually diminished over the past 10 years, and the trend appears to be due to the decrease of works using Japanese quail as an animal model or for biological studies. The flow of avian science-related papers on quail published in international journals remains about co nstant and low over the same period as the number of teams or laboratories with a quail research programme are few. On the other hand, commercial production of Japanese quail for eggs and meat is difficult to track precisely, and it is quite unequal across countries and continents, with increasing production in a few places, like Brazil. The futures of quail research and of quail production are not independent, however, and better links between both activities are needed to promote relevant research, explore new avenues of quail production, and help maintain this bird as an essential animal model.

Several factors may limit the development and viability of late-term embryos and hatchlings: 1 The nutrient content of the egg needed for the development of tissues and nutrient reserves (glycogen, muscle, yolk) of the embryo through to hatch; 2 The ability of the gastrointestinal tract to digest utilize nutrients from an external carbohydrate and protein-rich diet; and 3 The ability of chicks and poults to rely on the residual nutrients in the yolk sac during the first few days post-hatch. These limitations are manifested by in the “chick or poult quality” phenomena. Approximately 2% to 5% of hatchlings do not survive the critical post-hatch “adjustment” period and many survivors exhibit stunted growth, inefficient feed utilization, reduced disease resistance, or poor meat yield. These limitations can be alleviated by the administration of food in the hatchery immediately post-hatch, a technology termed “Early Feeding”, or by administration of food into the amnion of late term embryo, what we define as “In Ovo Feeding”. A great potential exists in “combining” the early feeding and the in ovo feeding methods. Since the modern broiler increases its body weight by 50-fold from hatch until market age at 42 days, the first few critical days of “adjustment” represent a much greater proportion of the bird's life span than in the past. Consequently, early feeding methods will have a great impact on overall growth and well-being of the bird, particularly as genetic selection for increased growth performance continues in the future.

Contamination of poultry meat products with Salmonella and Cumpylobucter spp. continues to be the main microbiological problem affecting both industry and consumers. In some countries, control measures appear to have reduced flock infection with Sulmonella, but other issues have arisen; these include an increase in multiple resistance to antimicrobials in certain serotypes and the recent emergence of S. Paratyphi B variant Java, also frequently multi-resistant. For intensive production systems, there is much information on sources and routes of Salmonella transmission and the relative risk of infection/contamination at different stages of production. Some possible reasons for control failures are discussed. In contrast, less is known about Campylobacter in these respects, and a better understanding is needed of the physiology and host-interactions of the organisms, and of their behaviour in poultry operations. On such knowledge may depend the future development of effective controls.

Genetic selection for growth parameters in broiler stocks has created parent stocks that are unable to self-regulate feed intake to a level that permits reproductive function. Modern broiler breeders are feed restricted to limit the incidence of reproductive disorders and excessive body weight gain. A high degree of feed restriction is common during the pullet phase, which has been identified as a welfare issue. This paper examines the productive and welfare implications of feed restriction in modern breeders and the implications of returning to ad libitum (AL) feeding conditions. Feed restricted hens are compared to ALfed hens to demonstrate the full range in potential results from eliminating or reducing the degree of feed restriction in broiler breeder management. Both full feeding and restricted feeding programmes impact bird welfare. The contrast of these methods is intended to provide background information for the development of a definition of what a normal or appropriate growth profile is for broiler breeders. The implications of overfeeding on the well-being of the birds make current feed restriction programmes the more welfare-friendly alternative, despite apparent drawbacks.

The low-input:low-output scavenging systems in Africa, Asia and Latin America and the pastured and organic farming systems in Europe and North America depend on the free-range. Nutrient resources available in free-range and scavenging systems can be assessed by three parameters: Scavengeable Feed Resource Inventory (SFRI); Range Coverage (RC); and Scavengeable Feed Resource Harvest (SFRH). SFRI is estimated by 4 procedures: determination of the quantity of Household Leftovers (HHL) added to the range and determination of the quantity of scavengeable flora and fauna using Pitfall Traps; Transect Mappings; and Quadrants. RC is assessed by 3 procedures: visual inspection; physical space measurement; and automatic monitoring of birds by telemetry. SFRH, or the intake of scavengeable materials (HHL, plants, insects and metazoans) from the range, is estimated by applying 3 procedures to the content of the crops of scavenging birds: visual identification; physical separation and weighing; and chemical analysis. The assessment methods and parameters are still rudimentary and require a lot of improvement in accuracy and repeatability.