Chickens (Gallus gallus) were the first avian species selected for whole genome sequencing because of their economic value, use as a food source, livelihood security and research importance. Any living organism contains a galaxy of genes which express all the phenotypes or characters by encoding proteins and peptides, and playing regulatory roles in the biological system. Functional genomics in turn, is a multidisciplinary approach to identify and demonstrate the functional roles of genes and other regulatory molecules such as microRNA and CpG methylation in biological pathways. In the last two decades, the chicken genome database has made significant advancements in accruing large amounts of genomic information through employing advanced bio-informatic tools. Several techniques such as cDNA microarray, serial analysis of gene expression, massively parallel signature sequencing, cDNA subtractive hybridisation and next generation sequencing have been utilised to investigate the genome-wide expression profile instead of revealing expression pattern of one or a few genes in various avian species. Expressed sequence tag or cDNA sequences are the key factors for identification of novel genes and understanding the complex molecular cascades of ontology. A large-scale cDNA library has been constructed from embryonic and adult tissues and consequently identified the presence of about 19,000 functional genes in chickens. The micro RNAs play crucial role in gene expression and to date, approximately 496 micro RNAs have been characterised. The non-coding RNA alters gene expression involved in cellular process, by modulating the chromatin architecture, transcription, RNA splicing, editing, translation and turnover. Functional genomics studies have been extensively used to identify genes associated with several production traits, immuno-genetic mechanism, host-pathogen interaction, pathogen biology etc. Nutrigenomics have determined the genomic mechanism involved in feed utilisation, metabolism and cholesterol synthesis etc., which ultimately reveal potential applications for improving the nutritional efficiency of birds. This review discusses the tools and utility of functional genomics approaches in chicken.

This review examines methods for culling small numbers of poultry on farm, considering both common techniques and methods that are yet to be tested on poultry. The aim of this review is to inform the design of experiments that will assess the pros and cons of culling techniques. The methods reviewed include manual and mechanical cervical dislocation, crushing methods (such as burdizzos or pliers), percussive devices, blunt force trauma and a brain-stem piercing device. Previous work on these approaches, of which there is a limited dataset, has relied on behavioural and brain activity as proxy measures of unconsciousness (insensibility) and death, however there remains some uncertainty as to when birds can be considered unequivocally insensible. These factors will be considered when deciding which of the methods will be recommended to be taken forward for further assessment.

The meat industry is one of the most competitive international branches and is currently in its mature stage of development. This paper concentrates on the prospects for European meat market trends and on results from primary quantitative research which was carried out using a method of individual personal interviews in a sample of 800 poultry meat consumers, aged between 18 and 65 years and in Slovenia. The aim of this paper is to present trends and projections on production and consumption of poultry meat, regardless of the fluctuations in the previous years, and to enable a better understanding of consumers' attitude and perception towards poultry meat. Taking into account that research has been conducted in the poultry sector in Slovenia generally and on consumer perceptions specifically, the results of this research may be used for planning further marketing activities.

In recent years changing public perceptions and attitudes, as well as a dynamic economic climate, have combined to potentially modify UK consumer behaviour relating to poultry meat. This paper reviews information relating to purchasing patterns, perceptions and decision making factors for in-home poultry meat consumption in the UK. The findings will be of interest to marketing practitioners as well as policy makers, academics and others with an interest in the poultry sector.

Depending on the bird species, about 33-86% of the egg content consists of albumen. In eggs from domestic fowl, albumen contains about 10.5% protein and 88.5% of water and may be regarded as the main water source for the developing embryo. Besides carbohydrates, lipids, and inorganic ions, over 90% of the solids in the albumen are proteins. Several factors are known to influence the amount and composition of the albumen: egg weight, age and genetics of the parent flock, amount and quality of the feed provided, environmental factors (e.g. temperature, light), position in laying sequence, and also storage conditions of eggs prior to incubation. The albumen content of an egg plays an important role during embryonic development. Not only for formation of sub-embryonic fluid, but albumen proteins are known to flow into the amniotic cavity, the yolk sac and finally the digestive tract of the embryo and are used as the main source of proteins for tissue synthesis. Partial removal of albumen had negative consequences on chick weight at hatch, reduced the amount of amniotic and allantoic fluid and may reduce the water content of the chick and the residual yolk. Replacing the removed albumen with saline, however, reduced the residual yolk weight without differences in water content, suggesting increased uptake and utilisation of yolk, possibly as a compensation for the removed albumen proteins. In addition to reduced chick weight at hatch, some authors report an asymmetric growth restriction where nutrients are diverted away from non-vital organs in favour of brain and heart, with a relative ‘sparing’ of these latter two organs. Partial albumen removal led to a reduced whole-body protein synthesis, similar to eggs containing naturally less albumen. Importantly, several studies reported some long-term effects of albumen removal on growth, indicating that prenatal environment will have life-long consequences.

The purpose of the present review is to examine the available data on the prevalence of some major axial skeleton pathologies in broiler chickens, which have a negative effect on welfare Data from literature and from our own research on the incidence of spondylolisthesis, spondylosis, spondylitis and scoliosis are included. Although it has a lesser extent on welfare compared to other skeletal abnormalities (mainly associated with leg problems), the axial skeleton pathology has a definite impact on broiler chicken flocks. Although some reports claim that skeletal abnormalities in broilers chickens are related to the genetic background of the birds and can be decreased by selection, they are still an important cause of pathology cases in the broiler chicken industry. The analysis of available literature has suggested that the prevailing axial skeleton abnormality in commercial broiler chickens was spondylolisthesis, followed by spondylosis, spondylitis and scoliosis.

The changes in the immune function of birds obtained during decades of intensive selection are rather disadvantageous. Today's chickens and turkeys are more susceptible to different infectious and metabolic diseases and exhibit a high mortality rate. Subsequently in recent years there is growing interest in the use of feed additives with immunomodulatory properties in intensive poultry production. This article reviews and discusses the results of current studies on the effects of yeast cell products on the different mechanisms of the immune system in poultry. The majority of the experiments presented in this review indicate that the use of yeast derivatives may have a beneficial influence on the immune system and resistance to the colonisation of pathogenic microorganisms. However, the positive effect of yeast derivatives on the immune system is not always reflected in an improvement in production parameters, especially when the experiments are conducted on healthy (non-challenged) birds.

Immunosuppressive viral diseases have become a major cause of mortality and economic losses in poultry industry mainly because of increased susceptibility of second bacterial infections and low response to vaccination. Nowadays chicken infectious anaemia is a great threat to poultry industry due to the large number of deaths and immuno-suppression it causes. Chicken anaemia virus replicates in erythroid and lymphoid progenitor cells, causing an apparent, sub-clinical infection that leads to depletion of these cells with consequent immunosuppressive effects. This review will summarise the currently available information about the chicken infectious anaemia virus and subsequent disease. Secondly, it will address the possible immune-pathogenic and immune-suppressive effects of chicken infectious anaemia in birds, including commercial poultry. Finally, the future prospects of vaccination against chicken infectious anaemia and other possible novel methods for the control of chicken anaemia virus are discussed.

Salmonellosis is one of the most frequent zoonotic diseases in humans and is associated with major public health and economic losses globally. Eggs and poultry meat represent one of the main sources of infection. Chickens are considered as a main carrier for salmonella and infected birds rarely show any clinical signs. The control of salmonella in commercial poultry production is essential because of the economic and public health consequences. Accordingly, the current European approach is based on a farm-to-fork strategy, in which each sector implements measures to minimise or reduce salmonella contamination. Control measures are most effective at the source, i.e. at farm level. Measures to decrease the prevalence of Salmonella enterica in poultry farms are expected to result in a lower incidence of human salmonellosis. The pre-harvest phase involves the use of all available tools, such as vaccination, implementation of biosecurity measures and additional efforts to achieve salmonella-free feed production. Amongst those tools, nutritional approaches can greatly contribute to reduce salmonella shedding and to minimise salmonella during processing, thereby producing safer food. Due to the high number of introductory sources for salmonella to infect a flock, various intervention strategies have to be implemented to minimise risks. Recently, it has been shown that salmonella impacts the gut integrity in chickens, therefore it is important to develop new strategies or combine different strategies to improve gut barrier function and gut health. This review describes certain selected strategies that may be used in farm control programmes in poultry.

Pheasants and peafowl have been used as ornamental birds worldwide because of their beauty and use as game birds. They can be hampered by the disease mycoplasmosis in breeding pens, wildlife parks and zoos. This review paper describes the prevalence, diagnostic procedures and different combinations of treatments for mycoplasmosis in these birds. This paper also discusses the association of prevalence with management practices.

Genomic selection is a recent paradigm shift for both animal and plant breeding. The availability of hundreds of thousands of markers covering the entire genome has provided an opportunity to increase the accuracy of estimated breeding values, better manage genetic variation and shorten generation intervals. This paper summarises how these new technologies can be applied to poultry breeding programmes to enhance genetic improvement.

This review examines the emergence of drift variants of low pathogenic avian influenza (LPAI) viruses, with particular focus on their occurrence in India. Influenza viruses are dynamic and continuously evolving, and variants emerge from the instability of these viruses due to their constant mutations through antigenic drift. The drift variants emerging from the LPAI viruses gradually acquire higher virulence, inflicting heavy mortality and severe economic losses. Different aspects covered in reference to the Indian observations include mortality, clinical signs, post mortem lesions, and differential diagnosis. In addition, the cause of death based on the typical lesions encountered, and the limitations of any vaccination programme to control the variants are discussed in a global context.

A gravity model was used to determine the impact of exchange rate volatility on turkey trade flows. Previous analyses of aggregate agricultural sectors or products have assumed the effect of exchange rate volatility is uniform, that is, it impacts the individual components of the aggregates in the same way. This is highly unlikely, given the differences in biological and marketing factors across commodities and sectors. In order to address this issue, we examined how exchange rate volatility affects international turkey trade rather than the more commonly analysed ‘poultry’ trade. Findings revealed that the effects of short- and long-run exchange rate volatility on bilateral turkey trade are positive and statistically significant. Increasing distance between importing and exporting countries has a negative effect on turkey trade flows, while being a member of NAFTA and EU-27 has positive impacts on those flows.

There has been growing interest in the development of natural methods of coccidiosis prophylaxis. Vaccination against coccidiosis with live oocysts is regarded as effective in the control of avian coccidiosis, but in some conditions, such as poor sanitary management or incorrect application of the vaccine, may lead to poorer performance, measured as reduced weight gain and feed efficiency, in comparison with prophylactically medicated birds. Such reports are the reason for widespread reluctance to use anticoccidial vaccine in broilers. This paper reviews broiler studies in which nutritional methods as performance and/or immune-supporting factor with regard to anticoccidial vaccination were investigated. The results of some of the studies presented in the article indicate that feed additives with immunostimulating properties, along with proper protein levels in the diet, may have a beneficial effect in cocci-vaccinated broilers.

The world poultry industry is under great stress due to parasitic diseases; coccidiosis being one which is responsible for substantial economic losses worldwide. In 1948 the first research paper was published about the treatment of coccidiosis with sulphaquinoxaline. After six decades, researcher's attention has focused on DNA vaccination, especially as certain anticoccidials have failed due to drug resistance and residues. Thus far vaccination is partially successful but is accompanied by disadvantages: e.g. instability, inferiority control, cost-effectiveness, and inefficiency in opposition to a large number of coccidian strains which are prevalent in different geographical areas. Due to developments whereby genetically engineered DNA can be administered in vaccine form to provoke cellular and humoral immune responses; there has been huge development in the practical application of this field. In the last decade a number of DNA vaccines employing different strategies have been tested to produce appropriate immune responses against coccidiosis. The DNA fragments taken from all the four important species, E. tenella, E. necatrix, E. maxima and E. acervulina were able to provoke appropriate immune responses against challenging infections with homologous species; however, most of them were not able to provoke a response with heterologous infection. The shared DNA antigen in two different species of Eimeria; E. tenella and E. acervulina was able to produce sufficient immune responses, not only against these species but also against E. necatrix, but not against E. maxima. E. maximum is the biggest and most complex of all the seven species and it has come ahead as a challenge for DNA vaccine researchers.

Because the production of oat geese in Poland, destined mostly for markets of Western Europe, has increased, there is a need for a review on the performance traits of these geese and on the quality of their meat and fat. Goose production is based on a genotype of Italian geese brought to Poland in 1962 and selected for improving their reproduction and meat traits. Currently the population of geese, their reproduction and the commercial birds derived from them, are referred to as White Kołudzka® geese. Selection of these birds is based on a programme based on genetic improvement of strains W11 (reproduction traits) and W33 (meat traits). The programme's aim is not only to enhance breeding and the performance value of these strains, but to produce, as a result of cross breeding, good quality of meat and fat in the form of the crossbred W31, and thus to produce oat geese that meet today's market requirements. Poland is one of the largest goose producers in Europe. Goose meat and fat show high nutritional quality due to the specific nutrition and conditions in which the geese are kept, i.e. in open-air runs and at pasture. Recently, goose meat has become increasingly popular and has attracted much consumer interest. This increase in demand requires more knowledge about the meat's nutritional value. Polish oat geese are reared up to 14 weeks of age, then fattened freely with oats up to the 17th week of age. Fattening with oats results in good quality meat and fat, with excellent sensory properties. The following paper reviews the rearing systems, slaughter value and quality of meat and fat of White Kołudzka® geese kept under semi-intensive systems.

Light presents one of the considerable factors after nutrition and genetics in bird health and welfare. Therefore poultry producers are continuously looking for new and innovative tools to apply in poultry production in order to economise rearing costs and save rising energy concerns. Changes in the light regimen, intensity, duration and wavelength have a profound effect on the behaviour, physiology and production performance of poultry. Moreover, bird welfare is a major controversial issue and the adaptation of a lighting programme with a proper lighting tool could impart a possible solution for the betterment of poultry welfare. Light emitting diodes (LED), due to their various beneficial characteristics over traditional incandescent and fluorescent bulbs; are gaining popularity with poultry farmers. Therefore, it can be suggested that the use of LED in poultry housing is advantageous due to its energy efficiency and long life as compared to the conventional light sources, and with the added benefit of its various colours and higher productivity.

In developed countries, small farmer entrepreneurs contemplating poultry production are becoming more interested in assessing mobile poultry processing units (MPPU) to add additional value to the birds they sell in urban or farmers’ markets. However, there continues to be a lack of viable poultry processing options for small flocks as evidenced by the recent United States Department of Agriculture map, which depicts the locations of both small farms and processing facilities, county by county, across the United States. This map substantiates the need for more affordable poultry processing options to serve small-scale farmers. Many small-scale farmers operate MPPUs under federal exemptions that exclude them from continuous inspections by the USDA's Food Safety and Inspection Service, but they are still required to meet all sanitation and wholesomeness requirements. Costs associated with processing are somewhat less under this exemption, but one is unable to sell poultry as having been inspected in the open market. The USDA-FSIS has also created a mobile slaughter unit compliance guide for those who wish to be USDA regulated. Either way, regulated or unregulated, the MPPU may be an affordable and efficient solution to add value to small flock production. Small-scale poultry farmers, both organic and pastured, may benefit from the opportunities associated with mobile processing.

Laying hen rearing systems have been the focus of scientific research for many years. Over the last few decades, new laying hen rearing systems have been rapidly introduced in an effort to harmonise poultry health and welfare with consumer, producer, industry and environmental demands. Given the above situation, the subject matter of this paper was a comparative review of the results obtained by different authors on the effect of rearing system on productive traits (egg production and mortality) and egg quality characteristics (egg weight, proportions of main egg parts, Haugh units, yolk colour and carotenoids) in laying hens. Although productive performance in alternative systems is often lower compared to conventional, intensive layers, eggs from alternative systems have been proven in numerous studies to have better nutritional properties. Moreover, research results indicate differences within rearing systems. In view of this, this overview of the literature on the use of different rearing systems in table egg production can serve as a tool in determining the future direction of research as well as an indicator of its practical application.

Recent progress has been achieved in the identification of quantitative trait loci (QTLs) and candidate genes, and they have been found to be very important for the production of chickens with more desirable meat characteristics. The major economic traits of chicken meat production were divided into two major categories, namely growth and carcass condition. In this paper, the QTL locations and candidate genes for the above mentioned traits are reviewed. The results presented here will provide guidelines for the selection of high quality and highly productive chickens through the marker assisted selection (MAS), which should be extensively used by poultry breeders and companies.