As I sit here at the turn of the year, it’s been interesting to reflect on how things have changed in the last few years I have been editing the WPSJ. Certainly there have been technological advances, with the creation of the online submission system, advances in search facilities via new technology at Cambridge University Press, and better and more affordable accessing of papers, including the recent ‘hiring’ of full papers for a 24 hour period at a very affordable price. In addition, the editorial team have enjoyed the support from the WPSA Board members, who have been very encouraging to our small team, for which I would like to extent my gratitude. We have seen the journal go from the strength to strength, first increasing and then maintaining a good impact factor year on year. As a small journal, which is rather specialised and only comes out four times a year, we do rather well in keeping up there with the major agricultural journals. Interestingly, in 2012, the impact factor of all the agricultural journals fell slightly by about 10%. What changes this reflects within the ‘publishing’ aspect of our sector has not been determined, but certainly the squeeze on research funding and time for people to write papers must be a factor. Many of the stronger journals are relying on ‘self citation’ of papers to maintain their presence – but fortunately this is not the case for the WPSJ, which seems to be holding its own. In fact, we have more papers being submitted now than ever before. Although I’m writing this in December 2011, we already have the June and most of the September issues filled for 2012. One problem this creates is that authors will find there is a longer ‘lag time’ between submission and publication – for which I apologise, but we have to take each paper in sequence to get them out in any sort of timely fashion. In some areas we still struggle to find suitable reviewers, so if anyone out there has sufficient expertise, please register online as a reviewer, stating the areas you are qualified to report on. Please note that reviewers have a heavy responsibility in terms of maintaining the quality of the reviews we put out (and I get the complaints!), so only put down those areas where you have full confidence in your experience. We very much appreciate the time reviewers give us free of charge for reviewing papers.

This issue again covers quite a range of topics, with some papers in two parts or as separate reviews of similar aspects. I trust readers will find them interesting and useful, and as always, whilst we endeavour to keep the diversity within each issues, sometimes, at random, the same topics will crop up at similar intervals.

I trust all our readers had some kind of seasonal break (which I am also endeavouring to do at time of writing), wherever you are in the world, during the New Year and that 2012 is turning out to be a prosperous and rewarding year for you all. I hope to see many of you at the 2012 WPC, which is the big event for WPSA this year in Brazil.

Dr Lucy Waldron

Editor

This paper concentrates on revealing the economic significance of geese commercially raised by community in Kars province, which is very famous for geese reproduction in Turkey. In the survey, the hatchery efficiency has been determined to be 65.9% while the mortality rate after hatching is 8.7%. The survey revealed that small businesses on goose breeding typically are not profitable. However, because women are mostly in charge of taking care of geese, demanding no wages in return, the labour cost is very low, increasing the business profitability of goose breeding in this area. Consequently, the results of the survey have indicated that in order to increase performance of goose breeding and to raise the level of profit, contemporary goose breeding facilities, including infrastructure, should be constructed, and those who deal with goose breeding need to be trained in the technical aspects of production.

This paper covers the domestication and distribution of chickens in different parts of the world and describes the global data bases containing information on chicken genetic resources. The review shows the dispersion of chickens from the putative centres of domestication to different parts of the world, although introduction of the domesticated chicken into Africa is poorly documented. Currently, there are three globally accessible data bases containing information on chickens; however none of these provide a comprehensive system for systematically classifying domestic chickens in developing countries in terms of their present-day uses, potential for the future and distribution within and across countries. Such a system should be developed to include indigenous chicken genetic resources at the same level of detail as for other farm animals. The data management systems should incorporate all available information at the molecular level. Such information is important not only for discerning the existing diversity but also for making decisions on conservation priorities. Addressing the gaps in information on indigenous chicken genetic resources should primarily be the focus on the Domestic Animal Genetic Resources Information System (DAGRIS). DAGRIS, as a virtual library of indigenous animal genetic resources in developing countries, could play a leading role in delivering systematic information on the diversity, distribution and classification of domestic chicken in the tropics.

Until recent years, planning broiler feeding appeared an easy task to implement. However, there are about ten feeding programs around today. ‘In-ovo feeding’, ‘hatchery or early feeding’, ‘pre-starter diet’, ‘three fixed NRC phases’ ‘multi-phased feeding’, ‘feeding time period’, ‘sequential feeding’, ‘choice feeding’, ‘restriction feeding’, ‘nutrient (mineral and vitamins) withdrawal’, ‘replacer finisher feed’ (withdrawal supplement feed) and/or pre slaughter feed (removal) and ‘enrichment feed’ are the main feeding programs that attract many involved in the poultry industry. With so many different feeding programs, an effective feeding plan might seem a complicated issue and difficult to conduct. The effectiveness and shortcomings of such programs are discussed so that a broiler feeding plan can be chosen more effectively.

Modern commercial broilers appear to have compromised immunocompetence, higher mortality and lower resistance to stressors. To overcome these, dietary manipulation seems to be the easiest approach, and this has been supported by research investigations conducted over the last few decades. The goal of enhancing the immune system of broilers is laudable for both economic and welfare reasons. Vitamin E (VE) is now well accepted as nature's most effective lipid-soluble, chain-breaking antioxidant. This antioxidant vitamin has been shown to improve both cell-mediated and humoral immunity in broiler chicks. However, the effect of this vitamin depends upon dose, age and genetics of the broiler chicks. Several mechanisms have been postulated for the beneficial effects of this vitamin. In this review, several aspects of the immunomodulatory effects of VE are reviewed.

Broiler ascites, first seen in the form of a high altitude disease, has increased in importance world-wide in direct proportion to the improvement in growth performance of modern broilers. At the same time, the incidence has spread gradually from high altitude (above 2000 m) down to sea level, which gave rise to proposals of alternative causes including infections, toxins and metabolic disorders. Our work centred on anatomical and physiological aspects and included hypoxia models, chemotherapy and selection for genetic resistance. The latter led to the development of ascites-resistant lines, which allowed resistant stock to become commercially available in South Africa.

The closure of the Poultry Section of the Onderstepoort Veterinary Institute brought ongoing ascites research to an abrupt end and some of the completed work was never published. This review of completed, ongoing and planned ascites work was at the time compiled as final report to the Director of the Institute in 1990. It came to light again recently and has been edited for publication. It also includes a new hypothesis on the reasons for the susceptibility of the domestic fowl and particularly broilers to hypoxic ascites.

Lithuania committed itself to conservation of its genetic resources by signing the Conservation Convention on Biological Diversity in Rio de Janeiro on June 11, 1992. In 1995 FAO recognised the Vishtines goose breed as being monitored internationally and included into the FAO Global Databank for Animal Genetic Resources and the World Watch List for Domestic Animal Diversity. Vishtines geese are rather large in size with a medium-sized head, blue eyes and straight short orange beak. The arched neck is of medium length. The breast is broad and deep. The back is straight, horizontal and the shanks are long and orange. There are one or two skin folds on the abdomen. The plumage is white. The final body weight of the goose and the gander of this breed reaches 5-6 kg and 6-7 kg respectively. Numerous scientific studies have been made with these geese in Lithuania. Biochemical protein polymorphism and microsatellite analysis tests with the goose breeds grown in Lithuania indicated that Vishtines goose breed is unique and can be distinguished by biochemical genetic individuality.

Recent studies have suggested that avian semen contains a high proportion of polyunsaturated fatty acids (PUFAs) which are characterised by an increased susceptibility to lipid peroxidation. Free radicals are produced as a consequence of lipid peroxidation and these can impact on the fertility of male birds. The seminal plasma has been equipped with a defence mechanism called antioxidant capacity which protects semen integrity against the negative impact of ROS (reactive oxygen species). From the available literature, it can be surmised that lipid peroxidation is one of the major causes of low fertility in male birds which can be remedied with supplementation of exogenous vitamin E. Vitamin E provides biological stability to spermatozoal plasma membranes by inhibiting the generation of reactive oxygen species (ROS). Recent studies have suggested a role of vitamin E in improving semen quality and subsequent better fertility. In this review the current knowledge of physiology of ROS and antioxidative role of vitamin E to treat avian male fertility is discussed.

Laying hens have a unique bone turnover due to the daily egg laying cycle. Laying hens have three distinctive kinds of bones related to egg formation: cortical, cancellous, and medullary bones. Cortical bone is a compact structural bone, whereas cancellous bone is the three-dimensional lattice-like honeycomb architecture at the end of long bones. Medullary bone is a highly labile woven bone lying in the marrow cavities. Medullary bone acts as Ca storage for egg shell formation. Thus, bone quality is closely related with egg production and eggshell quality. During the daily egg laying cycle, medullary bone osteoclasts alternately cease and accelerate bone resorption. Although osteoclast numbers are not changed during the daily egg laying cycle, considerable morphological changes in osteoclasts occur along with changes in calcium requirements for egg shell formation. Furthermore, the selection of proper methods is critical to obtain precise bone evaluation data, and include bone ashing, densitometric techniques, mechanical testing, or histomorphometry to evaluate bone status in laying hens. Since bone metabolism in laying hens is related to economic and animal welfare issues, better understanding of bone metabolism in laying hens would be important to enhance productivity and improve animal welfare.

Nitric oxide (NO) is generated in human and animal tissues from L-arginine. Its known effects include mediation of the parasympathetic nervous system (effects of aсеtуlchоline), smooth muscle tonus, apoptosis, and tissue differentiation. The physiological effects of NO attract significant theoretical and practical interest in medicine and agriculture due to its possible regulation of physiological functions.

It is known that embryo development involves intensive NO production, but the exact role of NO in embryogenesis is not clear. Elucidation of the features of NO metabolism in the embryo and their correlation with its development is necessary for the clarification of this role. The avian embryo is a convenient object for such research, because of its relatively large size and its development outside the dam, which allows control of all stages of the development.

This article reviews the scientific information on the physiological effects of NO, current hypotheses about their mechanism, and, finally, some perspectives of practical application in poultry breeding. It also reviews of the basic results of our own research that is conducted according to the program of RAAS. It has been observed that NO metabolites contents in embryo amnion and allantois of both egg laying and meat poultry breeds are very different. The value of the difference is more than one order of magnitude, which is seen in more than 30 lines and crosses of hen, quail, turkey and ostrich. It is possible that elucidation of the mechanism of action will allow active regulation of embryo development, as well as the potential for using the indices of NO metabolites content in selection work.

There is growing interest in developing natural alternatives to antibiotic growth promoters in order to maintain both birds’ performance and health. In the last decade, Turmeric has been extensively used in poultry diets. Turmeric is a natural herb of the ginger family, Zingiberaceae. Wide range medicinal properties of this plant have been advocated. In poultry feed, Turmeric has been extensively used in different concentrations, dosages and durations. In this review, the beneficial effects of this plant on growth, weight gain, feed conversion ratio, ameliorative effect on liver health, immunomodulatory and antioxidative effects are reviewed.

Organic acids and their salts have been approved by European legislation as an alternate source of antibiotic growth promoter in diets, because antibiotics are associated with problems due to potential residual effects via food animals developing resistant strains of pathogens. Citric acid (CA) is a weak organic acid which is a natural preservative and can add an acidic or sour taste to foods and soft drinks. It exists in small amounts in a variety of fruits and vegetables, most notably citrus. Penicillium mould and Aspergillus niger could be efficient CA producers on a commercial basis. Its inclusion in animal diets has been reported to decrease colonisation of pathogens and limit then production of toxic metabolites, improve availability of protein, Ca, P, Mg and Zn as well as serve as a substrate in intermediary metabolism. Its addition in drinking water is not promising for performance, but lower doses would be useful for sanitary aspects and gut health. Its inclusion at 0.5% in the diet improves performance and non-specific immunity of broilers. It also enhanced specific immunity against new castle disease in vaccinated broilers. Current data supports a recommendation in the broiler diet up to 0.75% in pelleted feed and 0.5% in mash diets, with a safety margin of 6.0%. Additional research is needed to determine the feasibility of its use in low nutrient density broiler diets.

The majority of the Kenyan population resides in the rural areas and is characterised by low income and food insecurity leading to high levels of poverty. Poultry production and in particular indigenous chicken (IC) production play a significant role in the economic and social life of these resource-poor households, contributing to cheap source of animal proteins and cash income. Indigenous chickens are present whenever there are human settlements and their economic strength lies in their low cost of production which is a characteristic of the resource-poor rural households. They are highly adapted to the harsh scavenging conditions, poor nutrition and disease and/or parasite challenges. Their low productivity has hindered their exploitation. This paper highlights the current IC production circumstances with a view to identifying the major challenges which need to be addressed in order to improve the IC productivity and thereby improve the livelihood of the rural households who are the custodian of these genetic resources. It is concluded that the IC in Kenya posses high genetic diversity and are popular among the consumers. There is potential to improve IC productivity in Kenya and therefore individual and national efforts are required that takes into account the whole IC production value chain.

Poultry production and in particular indigenous chicken (IC) production has been recognised as an avenue to improve livelihoods of the rural households. Previous attempts to improve their productivity have had little success due to, among others, lack of a holistic approach in solving the constraints and dissemination of inappropriate technologies given the production circumstances and market dynamics. Marketing as a constraint is often blamed for the failure of interventions to improve livelihoods, despite lack of saturation for IC products at local and national levels and the increasing demand for the same. This paper highlights the past improvement attempts and suggests strategies to improve IC productivity and thereby improve the livelihood of the rural households which are the custodians of these genetic resources. It is concluded that there is potential for improvement of IC production in Kenya given the available genetic and physical resources. However, a holistic strategy that increases productivity without increasing production costs or leading to loss of biodiversity must be developed. Such a strategy must take into account the various uses of the IC in a rural household.

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.