Well the conference season is once again upon us, and, at the time of writing, I have already attended two conferences for WPSA, and will also be at the Turkish meeting towards the end of the year, with fellow board members. It’s interesting to see how fast things can sometimes change within an organisation. The latest statistics show that we have several new branches, notably in developing countries, whilst in some more established regions we are actually seeing a decline in membership. As members are the lifeblood of any organisation, it’s essential to promote the WPSA and create an environment of enthusiasm for the future of poultry science. Indeed, we have much to celebrate, for plans to commemorate the 100th Anniversary of the WPSA for 2012 are already in the pipeline. Certainly the Journal will be hosting special inclusions to mark the centenary, so watch this space! However there are also many other technological aspects to the WPSJ now available for members – making it easier and more efficient for you to get hold of the information and papers we have on offer. Have a look at the information in this issue to see how you can get the most out of the Journal. For any of you who are not already registered, online subscription is a fast, convenient way to access information and papers. We are now also working towards access to the WPSJ via mobile phones – which is a great way for members in developing countries, where the postal system or computer access may be unreliable. As the world of science gets faster and broader, we all need a reliable, quick way to access papers and literature information, so please do take advantage of these technological tools to ensure you’re not missing out on any information relevant to your specific field of work.

The Journal continues to grow in terms of quality, standing amongst peer publications and general popularity – which is a great result for all involved. At the end of June we will have our next citation rating (impact factor), which has consistently improved over the last few years, and we hope it continues to do so. Please keep those papers coming in. I’m always looking for extra variety in topics covered, and don’t be afraid to send in a review that’s maybe not mainstream – we are always open to new areas of poultry science.

So, please take a few minutes to go online and have a look at how you can get best use from the information we have in the Journal and on the WPSA website.

Dr Lucy Waldron

Editor

The gizzard has a number of important functions, such as aiding digestion by particle size reduction, chemical degradation of nutrients and regulation of feed flow, and responds rapidly to changes in the coarseness of the diet. This review summarises findings on the function of the gizzard, the interaction between diet and gizzard function, and the nutritional consequences of these interactions. Due to the reported improvements in nutrient availability when structural components which stimulate gizzard development has been added to the diet, it may be recommended to include at least 20 to 30% cereal particles larger than 1 mm in size, or to include at least 3% coarse fibres such as oat hulls, in the diet.

Phytases have been used commercially since the early 1990s and have been the focus of considerable and sustained research for many decades. Despite this heroic effort there are still areas of persistent uncertainty such as the obscurity surrounding total compared with digestible calcium, appropriate modification to dietary sodium (and other electrolyte) concentrations, the usefulness of the amino acid and energy digestibility improvements and ultimately the effect of phytase on nutrient requirement. One further area which has attracted some attention recently is the effect of unconventionally high doses of phytase (i.e. >2,500 FTU/kg from Aspergillus niger or Escherichia coli) in an attempt to ostensibly ‘de-phytinise’ the diet. The effects of such ‘super’ doses of phytase can be considerable, and often beyond that which may be reasonably expected based on improvement in P digestibility per se. This review article addresses these effects and suggests mechanisms by which they may be explained.

The article details the results of a quantitative survey which was carried out by personal interview of 3200 fresh chicken meat consumers ranging between 15 and 65 years of age and residing in the selected countries of Central and South-eastern Europe. A positive perception of fresh chicken meat was determined in all the countries sampled, with consumers reporting it as a tasty and healthy meat source. Special attention was devoted to the importance of meat origin in the purchase-decision-making process. The importance of fresh chicken meat origin in the purchase-decision-making process were evident in all analysed countries of Central and South-eastern Europe.

Protein metabolism is considered to be regulated by amino acids, with major consequences on tissue development. There is evidence that lysine greatly affects carcass composition and muscle growth. In particular, a drastic effect of dietary provision of lysine has been observed on breast muscle development in chickens. Other essential amino acids, such as threonine and valine, do not have as pronounced an effect as lysine on body composition. Increasing lysine can also improve chicken breast muscle quality by increasing its ultimate pH and water holding capacity, but the underlying mechanisms are still unknown. Studies conducted over the last ten years indicate that, in addition to being substrates for protein synthesis, amino acids act as modulators of signal transduction pathways that control metabolism and cell functions. For instance, certain amino acids can modulate the activity of the intracellular protein kinases involved in the control of mRNA translation. Interestingly, enhanced responses to amino acids have been reported during the neonatal period, suggesting that early protein nutrition impacts on the development of broiler chicks. Methionine and cysteine have a very significant place among amino acids because they have several additional roles: they are precursors of essential molecules, for example cysteine is used for the synthesis of the antioxidant glutathione, and thus participates in the control of oxidative status, methionine is a source of the methyl groups needed for all biological methylation reactions, including methylation of DNA and histones, etc. These findings together indicate the importance of optimizing amino acid nutrition and providing a rationale for nutritional advice.

Moulting is a natural phenomenon in birds. Temperature variation and photoperiodic changes induce circadian and circannual rhythms, manifested by changes in the neural and endocrine systems, ultimately causing physiological processes resulting in a moult. The concept of induced moulting by feed deprivation arose during the early part of the 20th century as a solution to economic challenges of decreased egg production in commercial layer flocks toward the end of the first laying cycle as they approached the moult phase. Efficiency of feed removal programs in enhancing post moult productivity and economical feasibility insured a gain in popularity by the 1930's. In 2003, more than 75% of all flocks were moulted in the U.S. However, moulting with feed withdrawal caused risk to the health of birds by impairing the immune system and increasing susceptibility to various pathogens, especially Salmonella enteritidis (SE). During the 1980s, increased incidence of gastroenteritis due to SE was linked to forced moulting. The importance of challenges for conventional forced moulting was realized and animal activists, welfare organizations, researchers, consumers, and producers realized that alternative moulting methods were necessary. Ultimately, the United Egg Producers Scientific Advisory Committee, having dealt with the issue of feed withdrawal for moulting since the early 1990's, amended the Animal Husbandry Guidelines for U.S. Egg Laying Flocks to specify the use of non feed withdrawal moult methods after January 1, 2006. Furthermore, moulting hens would have to be fed nutritionally adequate and palatable food suitable for non-egg producing hens. Though metals or hormones are efficient moult inducers, results of studies showed that they had disadvantages like residual effects and physiological alterations, respectively. Diets supplemented with low nutritious feed ingredients are safe and demonstrate promising outcomes. Unconventional feedstuffs such as coconut meal and cumin seed meal are successfully used in layer and non feed removal moults in Asian and Middle Eastern countries. In the western U.S. (especially in California), local ingredients like safflower meal and tomato pomace are promising alternatives.

The following review details the development and current status of poultry meat in terms of marketing, purchasing and consumer decisions within the country of Greece. The aim of this paper is to identify Greek consumers’ perceptions of poultry meat. Taking into account that little research has been conducted in the poultry sector in Greece generally and on consumer perceptions specifically, these results will help to provide solutions in strategic marketing.

L-carnitine has indispensable functions in intermediary metabolism and is received by endogenous synthesis and from exogenous sources. It plays an obligate role in fatty acid metabolism by directing fatty acids into the mitochondrial oxidative pathway through the action of specialised acyltransferases. In poultry production, L-carnitine has a multi functional purpose, which includes: growth promotion, strengthening the immune system, antioxidant effects and improving semen quality. The concentration of L-carnitine in animals varies widely across species, tissue type, and nutritional status of the animal. It has been suggested that the L-carnitine requirement may be increased under certain circumstances such as via higher performance, various stress conditions and where the diet is deficient in animal protein sources. The review of L-carnitine functions uniquely includes the main aspects of this consequential feed supplementary inclusion in poultry nutrition.

Avian spermatozoa are characterised by high proportions of polyunsaturated fatty acids (PUFAs) which is associated with increased susceptibility to reactive oxygen species (ROS) and lipid peroxidation. Recent advances in avian reproduction have focused on the potential of ROS as one of the prime mediators of infertility. Although ROS are involved in many physiological functions of spermatozoa, their excessive production may result in oxidative stress. The production of ROS is enhanced during unfavourable environmental and stressful conditions, and an effective scavenging system is essential to counter the production of ROS. Antioxidants are compounds that suppress the formation of ROS. Enzymatic and non-enzymatic antioxidants build a powerful antioxidant system in avian semen which is able to protect it against ROS and lipid peroxidation. The balance between ROS and antioxidants in avian semen is a fundamental determinant of membrane integrity, sperm viability and fertilising ability. A regulating role of ROS in sperm function in mammalian sperm along with their counteractive mechanisms have been extensively studied; but their role for avian species reproduction remains to be elucidated. Various antioxidants belonging both to enzymatic and non-enzymatic groups can counter oxidative stress. Hence the rationale of using antioxidants is advocated.

The following review considers the history of poultry breeding to date, and the contribution of both traditional and molecular genetic methods in the selection of breeding stock and in performance improvements. The genetic aspects of eradicating disease and stress-related problems in broilers are discussed in detail.

The development of drug resistance in Eimeria is common because of extensive use of anticoccidial drugs for the control of avian coccidiosis. The significance of chemotherapy is evident from the fact that, in spite of advancement in the field of immunological, biotechnological and genetic methods, prophylactic chemotherapy with anticoccidial drugs is still widely used for the control of coccidiosis. In such situations, new drugs should be available to replace the older ones against which resistance has developed, however it takes a long time to develop any new compounds. It is therefore currently necessary to develop strategies to minimise the emergence of resistance in Eimeria strains and to prolong the effect of available anticoccidial drugs. This paper summarises the resistance status of Eimeria species in different parts of the world and reviews different types of resistance, mechanism of resistance development, factors involved in the development and spread of resistance, management of resistant strains and strategies to preserve the efficacy of the available anticoccidial drugs. Use of vaccines, synthetic and botanical anticoccidials and educating farmers about recommended coccidiosis control practices are discussed in this review, along with the integration of currently available options for the management of drug resistance and, ultimately, the control of coccidiosis.

Welfare issues and approaches are compared in the following review, for all major meat chicken producing countries. In certain countries, such as the United States and Australia, the industry comprises a small number of integrated, self-regulated companies, whereas in Europe the industry is more diverse, with greater competition, and more government regulation. There is much more meat chicken welfare research and regulation in Europe, and in particular the United Kingdom, than in countries with self-regulated industries, such as the United States, even taking into account the level of meat chicken production in the relevant areas. By contrast, welfare regulation in two of the world's major meat chicken producing countries; namely Brazil and China, is negligible. Some welfare issues are regional, such as high temperatures which are particularly problematic for free range birds, breeds selected for rapid growth and when birds are removed from fully-housed systems. However, similar welfare issues affect intensively-housed birds worldwide, which comprise the majority of animals produced. These include rapid growth rates, predisposing birds to heart and leg problems, especially ascites and sudden death syndrome, and high stocking densities, which inhibit locomotion and environmental exploration, predisposing birds to contact dermatitis. Welfare research in Europe has shown that highly stocked birds spend longer sleeping, congregate around feeders and are more fearful, as well as experiencing higher ammonia levels, which irritate their eyes and respiratory systems. The review concludes that intensive systems present similar welfare issues worldwide; however, European research is more directed to the behavioural and cognitive requirements of the birds, than in self-regulated countries. This will enable their industry to respond better to future welfare requirements from consumers.

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.