Well it’s been a busy time here in the office – as I have been off having bone graft surgery at the end of June and am now having to put up with a slow, but necessary recovery. Many thanks to all of you who have been in touch sending best wishes for my recovery.

There have been some excellent conferences – including the European Poultry Congress in Norway recently, which was a great success and has generated interest from authors wishing to submit review papers to WPSJ. Thanks to the organisers for publicising the opportunity for full publication with us and for anyone else organising such meetings, do be aware that WPSJ is always happy to consider suitable reviews for the Journal. Any papers that have been previously presented at a conference are issued with footnotes detailing which meetings they were given at originally.

Looking ahead, the board is holding their annual meeting in Korea at Jeju Island – which is apparently a very beautiful part of the world and somewhere worthwhile taking the time to explore outside of the Asian Pacific Poultry Conference, to be held in the third week of October.

The current issue contains papers covering a spread of topics, from disease through lighting systems, consumer preferences as well as some specialist nutrition papers. One problem we have recently had to deal with is papers coming in that are far too broad in their scope, considering the advances in many area of poultry science in the last twenty years. So we are now only taking more specific reviews on aspects, especially those relating to nutrition and zootechnical supplements. In addition, authors increasingly expect papers to be published quickly – however this is not possible with this type of Journal, as we are always running six to nine months ahead in terms of publication. So please be aware that, even with a fast turnaround on an individual paper, it will not appear for at least 2-3 issues that are published.

Looking forward to seeing many of you in Korea in October.

Dr Lucy Waldron

Editor

Over the years a large body of information has accumulated for the amino acid glycine, which prove that this amino acid is critical to animal nutrition in order for feeding to be more economic, eco-sustainable and supportive of animal health and food safety. Underpinning these glycine efficacies are its multifaceted metabolic interrelationships with other essential amino acids, and the resultant physiological responses. Key among these interactions is the inter-convertibility between glycine and serine, the participation of glycine in sulphur amino acid metabolism, and its biochemical linkages with arginine. Crucial to this is the metabolic release of glycine in threonine catabolism and cellular application in N detoxification- all linked to body amino acid homoeostasis. This is the first of a two-paper series reviewing the biochemistry and multifunctional metabolic involvements of glycine and the impacts on physiological efficiency of sulphur amino acids, threonine, arginine and total crude protein, mainly in broilers.

The aim of this review paper is to update, present and discuss the current research findings from recent studies regarding the efficacy of organic sources of microelements in poultry nutrition. Most intensively evaluated in poultry feeding studies have been organic forms, i.e., proteinates and amino acids complexes and chelates, of such microelements as Zn, Mn and Cu. The results of these studies are not always consistent, particularly in regard to performance indices; however, the majority of the findings from recent experiments indicate that organic minerals are an effective source of microelements, and can replace, with some advantages, inorganic forms of minerals in poultry diets. One of the main benefits is the option to use lower inclusion levels of minerals added in organic forms, which may reduce the mineral content in the resulting poultry excreta.

Haemorrhagic Nephritis Enteritis (HNEG) is caused by infection with haemorrhagic polyomavirus (GHPV) and is one of the major diseases of geese in Europe. Young geese (four to 10 weeks old) are susceptible to infection, and both horizontal and vertical transmission of GHPV has been confirmed. Infections result in significant gosling losses, with reports of up to 80% mortality. The most frequent pathological changes; haemorrhagic enteritis and inflammation of the kidneys give the disease its name. Additionally, oedema of subcutaneous tissues and visceral gout has been observed. Although it has been shown that GHPV infects Muscovy and mule ducks, these do not present with clinical symptoms, but can serve as reservoirs of infection for other species, including geese. There are no effective treatments for HNEG, however, data suggest that vaccination of breeders confers maternal immunity to goslings and that vaccination of day old goslings may prevent disease. In addition, reducing stress levels in these animals may prevent progression of HNEG.

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.

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.

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.

The use of light emitting diodes (LEDs) as a source of monochromatic light to determine its impact on immunity and meat quality in poultry is investigated in the current review. The use of LEDs in poultry housing is preferred over other conventional light sources. LEDs emitting blue, green and yellow wavelength have been shown to improve the immunity and meat quality responses in broilers. Blue and green light help to promote greater antibody production and immune function, compared to red light. Keeping birds under yellow and green-blue mixed lighting has resulted in softer breast and drumstick muscles while white light improved lean meat and amino acid content of meat. From the available research it can be inferred that birds perform better in terms of meat quality and immunity if reared under the environment of monochromatic light produced by LED for cost-effective and advanced poultry production.

During chick embryo development, there exists an antioxidant-oxidant balance in the tissues, which supports normal embryonic development and post-hatch chick viability. This balance is maintained by natural antioxidants including vitamins A, E, C and carotenoids, glutathione peroxidase (GSH-PX), catalase (CAT) and superoxide dismutase (SOD). Chick viability is an important factor in determining post-hatch health and profitability. Factors that interrupt growth and development during the embryonic period affect the overall performance and health during the post-hatch period. During the 21-day incubation period for chickens, antioxidant defence systems protect the embryo against the lipid peroxidation (LPO) derived from undesirable conditions. The purpose of this review is to explain the antioxidant mechanisms that contribute to chick embryo development resulting in a healthy hatchling.

Glycine is a multi-tasking amino acid involved in multiple metabolic and functional systems, including sulphur amino acids, proteins and immunoglobulins syntheses, blood haem and bile production. Glycine is also capable of eliciting responses at whole animal level, such as those promoting gut and immune health, animal welfare as well as feed/food safety. Empirical evidence shows that glycine supplementation can arrest systemic inflammation via deletion of cytokine production. Some investigators have corrected gut wall damage in challenge studies via gastric infusion of glycine. Efficacy data further document that glycine aids bone accretion in broilers fed reduced protein diets. Given these glycine bioefficacies, particularly in broilers, its nutrition needs to be critically assessed in the light of modern paradigms of animal welfare, feed-food safety, efficiency, reduced antibiotic application, and eco-sustainability. Such efforts should concentrate on precise estimation of inevitable ileal flow of glycine so as to generate a database on the digestible glycine levels in feedstuffs. Only this can provide for proper control of feed glycine density.

Controversies on dietary glycine optimum for broilers also need to be addressed, as this has significant ramifications for raw materials selection and eco-sustainability. Based on a meta-analysis of published reports a range of 1.91-2.27% of total glycine+serine is recommended in young broilers diets, depending on production goals. But clarity is still needed on how this may be modified by practical stress conditions. The efficacy of copious supplementation of crystalline glycine to promote key parameters of poultry health and zootechnical performance under different rearing conditions still needs to be resolved.

The nutritional benefits of consuming long chain ω-3 polyunsaturated fatty acids (PUFA), which are found predominantly in linseed for example, are well known. The consumption of poultry meat has increased in consumption by 80% in the last three decades. The best method of increasing long chain ω-3 PUFA consumption would be to increase the long chain ω-3 PUFA content in the edible tissues of poultry aimed for human diets. It has been shown that heart and blood vessel diseases, as well as the occurrence of atherosclerosis are a direct consequence of consuming products of animal origin in human nutrition which contain a high content of lipids rich in saturated fatty acids (SFA), which are the main causes of these diseases. For these reasons healthy foods enriched in PUFAs, particularly ω-3 fatty acids, have gained high importance because of their beneficial effects on human health.

Apart from the importance of being able to predict chicken carcass conformation it is also necessary to calculate the required level of fatty acids in the chicken diet that are incorporated into the edible tissues. Regression analysis is most often used for this prediction. The goal in regression analysis is to create a mathematical model that can be used to predict the values of a dependent variable based upon the values of an independent variable. The aim of this paper is to show possible solutions for broiler edible tissue enrichment with ω-3 fatty acids from linseed, and to give possible solutions to the inclusion level of fatty acids in the diets using regression analyses.

The importance of scavenging chicken production in the national economy of developing nations of Africa and its role in improving the nutritional status and income of many smallholder farmers has been recognised by several scholars and policy makers the world around. Scavenging chicken production is a profitable enterprise that contributes to poverty reduction especially among the resource challenged rural communities in most parts of the developing world. It is particularly suitable to smallholder farmers and landless peasants due to low capital investment, high cost efficiency, flexible production systems and low production risks. It has also a symbolic significance within the context of socio-cultural as well as religious functions and economically empowers the rural youth and women. Chicken meat and eggs provide a readily available, high-quality source of proteins, vitamins and micronutrients which are particularly essential for children, pregnant women and nursing mothers. Moreover, meat and egg from scavenging chicken present one of the most environmentally efficient animal protein production systems.

The major challenges of the scavenging chicken production in Africa include high chicken mortality due to predation and regular outbreaks of diseases notably Newcastle disease; imbalanced nutrition due to poor quality and quantity of feed materials; lack of organised marketing system and low performance related genetic potentials. The growing demand for scavenging chicken products in urban areas, identification and promotion of ethno-veterinary medicines, developing locally made and appropriate housing structures, selection among the scavenging chickens, organising farmers to increase bargaining power and shortening the marketing chain are considered as the major opportunities for the improvement of scavenging chicken production in Africa. The significance of indigenous chickens for farmers in African countries combined with many consumers’ preference for their eggs and meat suggests that these genetic resources are promising options for food security in the rural communities.

Although being the main bottlenecks for commercial poultry development in Togo, feeding and management practices retain little attention. Indeed, there is no proficient feed miller unit which can provide high quality feed according to the needs of the farmers. This is due to a lack of information on nutrition and relevant management tools or people trained as poultry farm managers. With the aim to alleviate poverty and hunger in Togo, an inter-university project [Catholic University of Leuven (KUL) and University of Lome (UL)] as a model for poultry development was being run from June 2006 to May 2012. Specific objectives of the project are 1) to provide insights and disseminate guidelines and information on adapted methods to improve poultry production and 2) to focus on development of new technologies in poultry production and implementation of research on better poultry nutrition, feeding and management practices.

Coastal and rural parts of Odisha are home to indigenous ducks, which are mostly reared for meat and egg production. Cross performance of the indigenous duck with exotic breeds, along with the suitability of crossbreeds for commercial rearing in the region are highlighted in this review paper. The crossbreeds perform comparatively better for most economic traits compared to the indigenous duck. The cross of the indigenous duck (male) with the Khaki Campbell (female) perform better in respect to different growth and production traits. Indigenous ducks in combination with White Pekin perform better in respect to juvenile growth, carcass quality and egg production. Most of the economic traits have showed desirable heterosis in crossbreds. The performance of indigenous ducks kept under free range conditions, molecular characteristics, mortality pattern and disease incidence, nutritional, and haematological studies are included in this review.

The World’s Poultry Science Journal is indebted to Prof J.A. Castello, Prof D.K. Flock, Dr D. Grastilleur, Dr S. Cherepanov and Prof N. Yang for the translations of these summaries.