Hydropericardium syndrome has caused huge economic losses to the poultry industry in Pakistan. The disease was reported for the first time in 1987 at Angara Goth, a broiler producing area near Karachi and given the name Angara disease. The disease is prevalent in 3–7 week old broilers and characterized by its sudden onset, accumulation of a jelly like fluid in the pericardial sac, inflamed liver with basophilic intranuclear inclusion bodies, congested kidneys and up to 70% mortality rates. Fowl adenovirus 4 has been found to be the causative agent. In Pakistan, the status of scientific research on various aspects of hydropericardium syndrome is quite unsatisfactory. There is an extensive use of formalin inactivated liver homogenate vaccines for the prevention and control of disease. Moreover, the gross lesions seen in post mortem examination are only the criteria for the clinical diagnosis of disease. Keeping in view the economic significance of hydropericardium syndrome, the need for additional scientific research on proper diagnosis and control of disease is suggested.

Well known as the cause of necrotic enteritis, C. perfringens (CP) is now recognized as causing a spectrum of effects including subclinical infection, mild disease with focal intestinal necrosis, diarrhoeal illness and liver disease, as well as the classic form of acute fulminant necrotizing enteritis. The mild and subclinical forms of infection appear to be widespread, and, possibly increasing in incidence. Furthermore, bacterial enteritis is increasingly being recognized less as an invasion by pathogenic organisms per se and more as an expression of the normal process by which the intestinal bacterial population changes overtime in response to changes in the intestinal environment. Such shifts in enteric bacterial populations have been referred to as dysbacteriosis. Management of the microbial ecology of the intestinal tract is therefore an important element of preventing disease, enhancing performance, and preventing foodborne illness. Diagnosis of emerging forms of bacterial enteritis including CP infection can be challenging and involves a comprehensive analysis of flock history and condemnation records, clinical signs, gross and histopathology, bacterial culture and empirical response to treatment, augmented by molecular techniques where available. Control measures are at present based on extensions of validated approaches to the control of the classical form of the disease: managing known risk factors for necrotic enteritis (coccidiosis, diet and litter quality) and the use of approved antimicrobial agents with proven efficacy against CP.

Rural poultry flocks in developing countries make little use of conventional vaccines or therapies. Appropriate vaccines must be robust, cheap and suited for local production in relatively unsophisticated laboratories. Only diseases producing high mortalities warrant attention. Appropriate therapies depend on local ethnoveterinary knowledge.

Newcastle disease is the most important constraint to the productivity of village chicken flocks. The Australian Centre for International Agricultural Research (ACIAR) initiated projects on vaccines to control this disease in rural flocks in 1984. Thermostable variants of the avirulent strains V4 and I-2 were developed and shown to be safe and effective in laboratory and village trials. Master seed of I-2 vaccine is made available without cost to developing countries. Vaccine is produced by a seed-lot system and involves allantoic sac inoculation of non-SPFeggs. Harvested allantoic fluid is the basis of the vaccine. Sustainable vaccination campaigns require components other than an appropriate vaccine. Appropriate extension messages must be developed to target the neglected village flocks, and the women who usually control them. Systems of cost recovery must be developed. Appropriate training must be available at all levels – to administrators, laboratory staff and village vaccinators. With the control of Newcastle disease, villagers can be convinced of the full potential of their flocks to produce food and income. Other interventions including housing, nutrition and control of otherdiseases can be introduced.

The thermostable vaccines have been tested in at least 30 developing countries and produced on a large scale in at least 9. International agencies otherthan ACIAR and various NGOs have supported the projects. The next village vaccine could be fowlpox, with virus adapted to production in the allantoic cavity.

The major killing disease of duck flocks in Asia is duck plague. An ACIAR project has seen the development of an improved vaccine in Vietnam The vaccine, adapted to grow in cultured chick embryo fibroblasts, is registered foe use throughout Vietnam. Various remedies, mainly herbal, are used on village flocks to improve performance. These probably do not assist in treating established disease.

The commercial industry could ask, are our vaccines too sophisticated and expensive, is there a place for food vaccines, should we investigate herbal remedies and how can we help the rural poor?

FPD is a common condition amongst commercially grown turkey poults. It causes the skin of the footpad to become hard and scaly, often developing horn-like pegs of abnormal keratin. The footpad can become swollen, frequently splitting. In the centre of the lesion the epidermis separates, and is often totally necrotic. Heterophils filter into the stratum germinativum.

The cause of FPD is complex, but many contributing factors have been suggested, such as dietary intake, skin structure, bird weight and sex, litter moisture and litter type. Litter quality is affected by many other factors such as stocking density, air temperature and moisture, season, consistency and amount of faeces (affected by diet), and drinker design.

Wet litter is the most likely factor affecting FPD, followed by biotin deficiency. Experimental evidence suggests that biotin deficiency causes FPD, and that commercial rations do not contain enough biotin to prevent these lesions. Supplementations of biotin have been shown to reduce the severity and incidence of lesions. Wet litter has also been identified as a possible causative agent. Broilers and poults reared on wet litter have an increased incidence and severity of FPD lesions, but the problem is alleviated by replacing the wet litter with dry. Biotin supplementations are able to reduce FPD to a certain extent if birds are reared on dry litter, but if on wet litter, lesions may still occur. Biotin intake and wet litter appear to be the factors most likely to influence the development of FPD.

Experimental results are difficult to compare because rearing conditions differ. Further experimentation is needed to determine the optimum amount of biotin required for healthy growth and lesion free foot pads, and to ascertain the real effects of other suggested causes.

Egg production in the EU (15) increased by 12.2% over the last decade. In 2003 it reached a volume of 96.4 billion pieces. The leading countries in shell egg production are Spain with a share of 20.1%, France and Italy with a share of 17% respectively 14%. The self-sufficiency rate for eggs shows a great variety in the EU. In 2003, The Netherlands had the highest surplus with a rate of 175%, whereas Germany showed the highest deficit with a self-sufficiency rate of only 71%. Shell eggs are traded mostly within the common market of the EU. The Netherlands is the leading exporting country; Germany is the leading importing country.

Organic egg production has also increased continuously over the last decade, without, however, reaching higher market shares. The contribution of organic egg production differs considerably among EU member states. Denmark has the highest share, followed by Austria and the United Kingdom; on the other hand, in southern European countries, organic egg production only plays a minor role. In spite of the increasing production volume, trade with organic eggs is still relatively unimportant in the EU.

The new EU directive for laying hen husbandry and the new German directive will have far reaching impacts on egg production and egg trade in the EU. Due to the banning of conventional cages from 2007 on in Germany the amount of alternative egg production will increase dramatically in this country, but it is a still open question if the consumers will buy these more expensive eggs. The self-sufficiency rate for eggs will decrease from 71% to about 35% and force Germany to import about 10 billion shell eggs per year or about two thirds of all eggs that are being traded on the world market.

Any approach which aims to improve the quality and safety of eggs, is of limited value unless it can relate to the incidence of breakages in the field, and can be applied either directly to breeding programmes or used as online tools for quality assurance. Online systems require the method of assessment to be non-destructive. This is probably not so important for breeding companies who tend to gauge the usefulness of an eggshell quality measurement by its ease of measurement, its heritability and, its genetic correlation with other phenotypic traits. Historically, qualitative measures such as shell breaking or puncture strength, non-destructive deformation and specific gravity have been widely adopted as tools in selection programmes. The dynamic stiffness is a novel eggshell quality measurement, which could be utilised by poultry breeders as it has a moderate heritability and high genetic and phenotypic correlation with other shell quality traits including eggshell breaking strength. This non-destructive measurement could also be applied on-line to monitor shell quality. An alternative approach is to use genetic markers as tools to aid conventional breeding programmes where an important eggshell quality trait is practically too difficult or expensive to fully exploit. Marker-assisted selection for the genes coding for organic matrix proteins may provide a way of incorporating other beneficial egg quality traits into selection programmes in the future.

Poultry is a major reservoir of Campylobacter jejuni, which is currently the leading cause of acute bacterial diarrhoea in western countries. This results in substantial accumulated economic loss due clinical costs and lost working hours. In developed countries reinforcement of hygienic practices and consumer education have so far been inadequate to significantly decrease numbers of human cases of campylobacteriosis. The control of poultry associated infection in humans may also depend upon the control of Campylobacter colonization in broiler flocks. However, sources of C. jejuni and the transmission routes through which broilers become colonized are not clearly defined. A better understanding of C. jejuni epidemiology is urgently needed. This review summarizes current theories on the epidemiology of C. jejuni broiler colonization.

The global poultry sector is divided into a large-scale commercial sub-sector dominated by international, vertically integrated companies, and a small-scale subsector that provides up to 90 percent of total poultry production in some of the least developed countries. The fast reproduction cycle, low unit costs, economies of scale in research and appropriation, and control of the produce are driving factors in the commercial sector. Private research concentrates on technologies that are likely to result in market applications and returns to investment. Private incentives for animal research are strongest where markets for improved technology are large, technical advances can be made quickly, and intellectual property can be protected. To date, technological protection strategies and contractual practices, rather than formal intellectual property rights strategies, have dominated in the commercial poultry sector. Poultry breeding companies have developed a highly successful way of protecting their intellectual property investment in superior breeds by exploiting heterosis, and the deleterious segregation of hybrid stocks in the next generation. Thus, by restricting access to the pure parent line stock (a form of trade secret) and by selling F1 generation birds, a breeding company remains the sole supplier of useful material. Patents do not yet play a role in poultry breeding, but breeding for disease resistance might change this in the future.

This paper explores the flow of poultry genetic material between developed and developing countries, investments in the poultry sector in developing countries, and economic and legal issues involved. In terms of genetic resources, the main questions concern how the division in the poultry sector affects the full portfolio of poultry genetic resources and if this division has an impact on the traditional small-scale subsector. The analysis is based on country reports to the First Report on the State of the World's Animal Genetic Resources process, studies on flow of genetic material and commercial transactions, and genetic distancing.

Commercial broilers are increasingly being subjected to environmental temperatures that are above their comfort zone. This is mainly because birds are growing faster than before and are therefore larger at any given age, but also because broiler production is being introduced as a farming system in environments that are unsuitable for such production. It is not economic for most producers to modify the environment within the broiler house to account for these problems and so it would be useful to know of nutritional strategies that could be used to reduce the effects of heat on broilers in the finishing stage.

Nutritional strategies discussed in this paper include the use of feeds with a high ratio of net energy to metabolisable energy, feeds whose amino acid composition is closer to that required by the birds, feeds with additional salts or vitamins and the use of pelleted feed and timed feeding. However, dietary modification will increase the cost of feed and the producer will usually not reap a net benefit. Some advantage may be gained by adding vitamins C or E to the feed, because of their action in reducing lipid peroxidation resulting from the increased body temperature of the bird: but it is impractical to reduce the heat increment of a broiler feed unless poor quality ingredients are currently being used. Heat production by the broiler may be lowered by reducing activity, by feeding pellets instead of mash, or by withholding access to feed before the temperature increases to stressful levels. Some improvement in performance can be obtained by increasing water intake. This can be achieved by cooling the drinking water and by adding salts, though these are only effective if the water is kept cool.

Most nutritional strategies that have been proposed as a means of reducing the heat of digestion in the broiler result in a maximum theoretical saving in metabolic heat production equal to the effect of lowering dry bulb temperature in the broiler house by about 1°C. None of these strategies is as effective in terms of growth rate, feed conversion, liveability or carcass quality as reducing the radiant heat load on the birds by making appropriate modifications to the structure of the broiler house and to the husbandry practices employed.

In the near future EU-legislation will ban the use of conventional battery cages, while national legislation in some countries in Western Europe will ban beak trimming as well. The ban on battery cages and beak trimming causes an increased risk of feather pecking and cannibalism in laying hens. Many factors influence feather pecking behaviour, but this paper focuses on nutritional factors. Nutritional factors can have positive and negative effects on feather pecking behaviour in laying hens. Severe feather pecking has been demonstrated in birds that were fed a too low mineral level in the diet, a too low protein level or a too low amino acid level (methionine, arginine). Sometimes somewhat more feather pecking was found when layers were fed diets with mainly vegetable protein sources as compared with diets with protein from animal origin. Also more feather pecking may occur when the diets were fed restrictedly, fed coarsely ground, or fed as pellets. Feeding high-fibre diets, low energy diets, or roughages reduced feather pecking. Providing additional grain or straw in the litter during rearing could result in lower levels of feather pecking behaviour in adult stages. Some of these positive effects on feather pecking seem to be related to the time birds spend on feed intake and foraging. This paper gives an overview of the relationships between the occurrence of feather pecking behaviour and nutritional factors, such as diet composition and feeding strategies in laying hens.

An increased knowledge of endocrine systems during incubation not only results in a better understanding of fundamental aspects of embryonic development, but also may lead to new practical applications. A first and immediate aspect is the possibility of early sex diagnosis based on current knowledge of sex determination. The current practice of killing day-old male chicks of layers results essentially from the improved efficiency of modern egg and meat lines, which were selected in opposite directions. The disposal of unwanted male chicks from layer lines causes increased welfare and ethical concern. Therefore, attempts have been made to interfere with sex determination or to identify the unwanted gender of the embryo at a certain stage of development (e.g. based on endocrine differences) where public concern is no longer a point of resistance against elimination. Thyroid hormones as well as glucocorticoids are known to be involved in several events leading to hatch and in the quality of the hatchling. Both seem to be strongly influenced by a common hypothalamic factor in the late chick embryo: corticotrophin-releasing hormone (CRH), CRH-related urocortines or analogues for CRH-receptor activity may be combined with in ovo vaccination for stimulating or synchronizing hatching activity. A next question to be asked is whether incubation conditions that produce the best hatchability also automatically result in chicks of the highest quality with the best desired postnatal performance. During prenatal development, most of the functional systems develop from an open loop system without feedback into a closed control system with feedback. This is already documented for endocrine systems such as the thyroid, the corticotroph and the gonadal axis. For functional systems, critical periods seem to exist and it is presumed that these coincide with the transition from an open into a closed feedback control system. In consequence, variation in incubation conditions such as temperature may induce a lifelong determination of physiological control systems, most probably via long-term changes in the expression of related effector genes and this may be defined as epigenetic adaptation. This opens possibilities to improve incubation conditions, not only in view of hatchability/chick quality but also taking long-term effects into account. Also it may redirect, at least to some extent, development as a function of the aims set forward, e.g. metabolic conditioning.

Tibial Dyschondroplasia (TD) is one of the most prevalent skeletal abnormalities observed in avian species; it causes enormous economic losses and is a major animal welfare problem. It is characterized by lesions composed of uncalcified, unvascularized cartilage that can extend from the epiphyseal growth plate into the metaphysis. The disease development and progress have been attributed to dietary, environmental and genetic factors. Irregular cell differentiation of the chondrocytes that populate the growth plate, with consequently aberrant cartilage vascularization and mineralization, has been hypothesized to be involved in the etiology of the disease.

Various tools available for the study of TD are described in the present review, and their advantages and limitations are discussed. We describe the morphology of the growth plate, with especial emphasis on the differences between the mammalian and the avian ones. We highlight vascularization as a possible cause of TD, and suggest that matrix metalloproteinases (MMPs) play an important role in cartilage vascularization and TD development. The disparity between broilers and turkeys MMPs suggests that they differ in their regulation of vascularization, so that different strategies may be required in dealing with TD in broilers and in turkeys. The high body mass of the modern meat-type birds has been implicated in the development of TD. A model was established to evaluate the effect of mechanical loading on the bones of young chickens, without any dietary manipulations: increased loading caused enhanced vascularization of the growth plate together with increased MMP-9 expression, without any changes in the incidence of TD, which suggests that the increased loading is not in itself the cause of TD.

At present, the cause of TD is not known, but multidisciplinary research at various levels such as a genomic approach based on microarray technology and the chicken genome project, together with cell and organ culture methodology, genetic selection, nutritional manipulation and environmental approaches will provide us with better understanding of the molecular mechanisms underlying TD, and should pave the way for future reduction in its incidence.

Except for conventional cages, the most common housing systems for laying hens comprise deep litter, aviaries and more recently furnished cages. Layers in floor systems may also include out-door keeping. Furnished cages will be the only legal form of cages in the EU from 2012 (1999 EU-directive) but have as yet only been installed in significant numbers in Sweden and partly in Norway, Germany and Great Britain. Climate, feed, bird genotype, group size as well as the legal possibility to beak trim or to use certain medical treatments (mainly against endo- and ectoparasites) or not, are all conditions affecting results with different housing systems in different countries. Offering benefits to the bird as regards increase in behavioural repertoire as well as providing more space, all alternatives to conventional cages, require new orspecial knowledge of management. This is due to the fact that these systems often include higher potential risks in production and health of layers. This especially applies to non-cage systems (Petermann, 2003). The main issues to control in largergroup floorhousing are parasitic disorders, outbreak and spreading of cannibalistic pecking, increased feed intake, misplaced eggs, catching of spent hens and airquality (dust and ammonia levels). Many management practices to reduce some of these risks have been presented including rearing method, medication, vaccination, light intensity, genotype, feed composition, beak trimming and – for improved air quality – the use of spraying/fogging with water or oil as well as more frequent manure removal at closerintervals have been practised. Coming in a wide range of models and group sizes, the furnished cages attempt to combine the benefits and reduce the disadvantages of floorkeeping and conventional cages. The most developed models of furnished cages provide similar production results to conventional cages. However, differences still exists e.g. in egg quality traits between models. Design and location of nests, perches and litter are all important factors.

In conclusion, future trends in investments forhousing system in egg production will have to take into account several factors apart from the degree of success from technical development of each system. These will probably involve national directives regarding beak trimming, stocking densities, directives of withdrawal times of medication and occupational safety on one side and national markets and trades fordifferent categories of eggs on the other.

An investigation was undertaken to study the farming system of Nageswari ducks in the North Eastern part of India (Assam), where this important egg-type native variety of duck was found only in few areas of the Cachar and Karimganj districts of Barak Valley zone. A total of 1702 respondents were selected randomly covering 40 villages spread over 8 zones within two districts. Results of the study in respect of socio-economic status of the farmer, geographic and demographic distribution, husbandry and feeding practices, production performance, incidence of diseases, mortality pattern and health protection programmes, marketing, finance and costs and returns from the flocks are highlighted.

Intact eggs can become contaminated with Salmonella as a result of infections of the reproductive tissues of the laying hens but also by penetration through the shell. In this paper, the penetration of Salmonella through the shell of hen eggs is reviewed. A description is given of the advantages and disadvantages of the various methods used to study bacterial penetration through the shell and membranes. The possibility of Salmonella contamination of the shell after lay is included because shell contamination is the first requisite for penetration. Various factors affect the probability of bacterial penetration. Both the intrinsic and extrinsic factors are highlighted. For the extrinsic factors, the influence of bacterial strain and number of organisms, temperature, moisture and immersion and storage conditions on the probability of Salmonella penetration through the shell is described. With regard to intrinsic factors, the presence of cuticle, shell characteristics (shell quality, porosity, shell defects) and membrane properties are summarized.

Delivery methods for commercial scale applications must be simple, inexpensive and cost-effective. The use of live vectors such as fowl adenoviruses (FAV) has previously been proven successful for the effective oral delivery of chicken interferon gamma to broilers under commercial growing conditions. FAV can be delivered via food or water or can be used as a spray. The ability of cytokines to modulate immune responses to vaccines and their therapeutic and growth promoting capability makes them an important component in future health management strategies for poultry. In this report, we describe the development of recombinant FAV vectors expressing chicken interleukin-2 (ChIL-2) and chicken myelomonocytic growth factor(cMGF). The ChIL-2 and cMGF genes were cloned into the right hand terminal region of FAV serotype 8, under the control of the adenovirus major late promoter. The in vitro biological activity of FAV-ChIL-2 and FAV-cMGF was comparable to that of the corresponding recombinant proteins expressed in prokaryotic (E. coli) and eukaryotic (COS cell) systems. These constructs may be particularly useful as therapeutics formucosal infections.

Corn and soyabeans may not be available in many countries particularly those which do not have sufficient foreign currency or the capacity to grow them. This paper outlines strategies that may be important under these circumstances. Alternative feedstuffs and various feeding systems may be used to support poultry production. Alternative ingredients such as rice bran, pearl millet, cottonseed meal and grain legumes are discussed. Evidence is presented showing that amino acid requirements of layers and broilers may be too generous particularly in countries where climate, management and disease can impose production constraints. The ability of finishing broilers to perform well on very low-energy diets allows the inclusion of alternative feeds and by-products into formulations. Very low protein diets based on cereals and free amino acids can be used for layers without loss of performance. Self-selection of feedstuffs may be an important strategy in reducing feed costs of broilers and layers. The concept of matching production with available feed resources may compromise broiler growth and egg production, but in many countries this may be the most economical choice. Countries in the humid tropics usually have reduced poultry performance. The effects of high temperature and humidity are difficult to overcome. The vexed questions of the escalation in the price of fossil fuel and the outbreak of avian influenza, both seemingly without a solution, are clouds hanging over an otherwise buoyant industry.