A happy new year to all our members and readers – it being early January as I am sat writing this editorial for the first issue for the WPSJ in 2013. It appears that the WPSJ is becoming ever more popular with authors – which is an excellent thing, but is also an issue that needs to be addressed! For those not well versed in editing and publishing papers at the ‘business end’ of things, our small journal is completed and prepared some four months before publication. Papers have to be proofed and checked at this time, and then the final latest news and editorial is done some 8 weeks before the issue appears (to try to be as up to date as possible). Since I have been running the journal we have seen an expansion from 8-10 papers per issue typically, up to 12-15 papers per issue. However, this increase is barely enough to keep up with submissions, which have risen dramatically in the last few years and since submission has become available electronically via ScholarOne and Cambridge Journals Online, as well as accessible via our own website. This extra backlog means that authors will have to be a little more patient about getting their paper out in press, as we have to wait until space in issues becomes available. We always ensure papers are taken in numeric order as much as possible, to save any becoming too delayed – but this depend on the nature of the paper, speed of reviewing and revision submissions. At our recent end-of-year round up of status of the Journal, we have already filled the June issue and September is nearly full as well.

I do trust you have all seen the information regarding requesting print copies from now on, otherwise this issue will be the last one you receive by post – although it will be fully available online to all members going forward. If you haven’t got your online log in information, go to the website and request it today. These changes in journal distribution are to save much needed revenue (from printing and postage costs) from the journal that can then be used in more useful ways – such as supporting the speakers bureau and travel grants. Please remember to contact the WPSA if you still require a print copy – but also consider the financial and environmental implications of extra copies before doing so – especially if others in the same department or office also receive a copy. Perhaps nominate one person in your office to get a print copy only, and share it round. Every little helps, so the saying goes, and each one removed will allow us to do more good works with the resulting revenue.

We have some new and varied topics in this issue – including two papers regarding climate change and its impact on migrating birds, which is highly topical especially with respect to disease control. I trust that you find something of relevance to your own work in this and every issue, whether in printed or electronic format. So please don’t forget about the changes in distribution, and make sure your copy in whatever form is secured for the next issue due out in June 2013.

Dr Lucy Waldron

Editor

Trace minerals are an essential part of poultry diets, even though the trace mineral requirements recommended by the NRC (1994) for poultry are based on very limited research work. For poultry producers, mineral salts are routinely over-formulated to ensure adequate levels are fed and requirements are met. This practice has caused concerns regarding optimising the genetic potential of modern breeds and environmental pollution. In recent years, extensive research work has been carried out to compare organic mineral sources, such as proteinates or amino acid chelates, with inorganic forms in poultry diets. This paper reviewed the research results conducted globally to date with mineral proteinate (Bioplex®, Alltech Inc, USA) including Zn, Cu, Mn and Fe. These replicated trials have used broilers, pullets and laying hens of different ages and in various practical raising conditions such as cages and floor pens. The main findings include: 1) mineral proteinate has a higher retention rate and relative bioavailability value than reagent grade inorganic salts; 2) the antagonism between minerals such as Zn and Cu could be avoided by using organic forms; 3) supplementing high levels of Cu or Zn as inorganic salt in poultry diets negatively affected the efficacy of phytase in the diet, which could be overcome by using mineral proteinate; 4) the replacement of inorganic minerals with lower level organic forms can support the optimal performance of broilers and layers and minimise the impact of minerals on the environment.

Many birds are able to modify migratory strategies when selection favours an adjustment. Climate change is provoking a range of responses from avian migrants and affecting their relationship with other biological systems. This is the first part of a two-part review that aims to summarise the available literature on the impact of climate change on migratory birds and how those changes will subsequently affect the spread of poultry diseases. Part I reviews the effects of climate change on the ecology of avian migrants; it was found that climate change has evoked several changes in birds, including changes in avian phenology, poleward shifts in avian distributions, modification of migratory distances, direction and activity, and alterations to movement patterns and destinations. Based on predictions for future climatic trends, climate change will continue to favour changes in avian migratory strategies and behaviour, emphasising the importance of investigating how these adjustments will affect the relationship between avian migrants and bird-borne pathogens.

During the past fifteen years, phytoadditives in animal nutrition have attracted attention for their potential role as alternatives to antibiotic growth promoters. The goal of this paper is to review the current scientific data on the use of phytoadditives in broiler nutrition. The efficacy of phytogenic applications in broiler nutrition depends on several factors, such as composition and feed inclusion level of phytogenic preparations, bird genetics, and overall diet composition. Difficulty arises when comparing different studies using phytoadditives due to the large variation in composition and sourcing, thus the potential biological effects of phytogenic compounds may differ. However, a great amount of research data supports a potential role of phytoadditives as natural, non-antibiotic growth promoters in broiler nutrition. The mechanisms behind growth promotion are far from being elucidated, as data on phytoadditive effects on nutrient digestibility, gut function and the immune system are still scarce. Phytogenic intake may certainly depress pathogen growth in the gut, however an understanding of their effects on the complex gut ecosystem is still far from clear. There is insufficient amount of studies describing the effects of phytoadditive dietary intake on carcass meat safety, whereas the beneficial effect of phytogenics on carcass meat quality is very well documented. As the last point of this review, further considerations on the efficient applications of phytoadditive compounds in broiler nutrition are given.

Egg storage is a common and important practice in the poultry industry. Knowledge of the effects of storage on the egg, the embryo and incubation yield is important for planning incubation by hatcheries. Recommendations for storage environmental conditions depend mainly on the breeder age and storage time. Storage from seven days or more alters the characteristics of albumen, reduces incubation yield, increases incubation period and can damage embryonic development. When working with long storage periods, the adoption of management practices such as storing the egg with the thin tip down, egg turning during storage and pre-storage incubation should be considered to reduce the negative effects on the incubation yield.

One of the environmental challenges that the poultry industry has faced is manure utilisation and/or disposal. Poultry manure and its nitrogenous compounds can be a potential pollutant causing eutrophication, nitrate or nitrite contamination of water, ammonia volatilisation, and acid deposition in the air. Therefore, reducing nitrogen excretion and emissions in poultry manure is important to maintain a clean environment. Proper nutrition is an important first step to optimise performance and growth in animals as well as to reduce the negative impacts on the environment. Amino acids are components of protein nutrition that greatly influence animal growth. However, excess or insufficient amino acid supplementation in diets increases nitrogen excretion and emissions. One way to reduce this is to prevent uricase activity in the microflora in poultry manure. Egg yolk antibodies are economic alternatives for administering in feed to poultry. Supplementation of feed grade antibodies into poultry diets can be a potential approach to minimise bacterial uricase activity and reduce ammonia emissions from poultry manure. In order to use this dietary strategy effectively, a well-balanced feed formulation and a more practical way of delivering the antibodies in feeds remains to be developed.

Campylobacteriosis is the most frequent zoonotic disease in humans worldwide. Poultry meat contaminated by Campylobacter jejuni (C. jejuni) is an important source of this enteric zoonosis. Broiler chickens are the common natural host for this pathogen and infected birds carry a very high Campylobacter load in their gastrointestinal tract. Therefore, intervention at the farm level by reducing pathogen colonisation should be taken into consideration in any control policy. In addition, hygienic measures at the farm and control measures during carcass processing can reduce Campylobacter numbers on the retail product. It is important to differentiate between prevention and colonisation-reducing measures, which intervene at a different stage of the infection process. Several approaches have been conducted to reduce the number of Campylobacter in poultry, such as vaccination, passive immunisation, bacteriophages, bacteriocins, organic acids or their derivatives and medium chain of fatty acids, all with varying degrees of success. Nonetheless, to date there is no reliable and practical intervention measure available to reduce colonisation of the broiler gut with Campylobacter. A possible way to reduce Campylobacter contamination in poultry is to develop new strategies at the primary production level. As a consequence, it has become necessary to develop alternatives such as beneficial microorganisms (probiotics). The use of probiotics can help to improve the natural defence of animals against pathogenic bacteria and is an effective approach for livestock to reduce bacterial contamination. This review summarises current on-farm control options to reduce the prevalence and colonisation of Campylobacter in poultry. The interaction between poultry welfare and Campylobacter colonisation is also discussed.

Over the last five years, the costs of poultry feed ingredients have increased substantially. This has been due to an increased use of corn for ethanol production and a greater overall global feed grain demand. Across the poultry industry this has led to higher production costs and reaffirmed the importance of feed efficiency on profitability. The effect that an increase in feed costs has on profitability is a clear driver for the selection for birds with better feed efficiency. Feed efficiency selection can be achieved using a number of different analytical methods. Selection for feed conversion ratio (FCR) has been used to improve feed efficiency with success but using a ‘ratio’ trait has mathematical limitations because selection pressure tends to be placed on the component traits of FCR in a non-linear manner. Another measure, residual feed intake (RFI) shows moderate to high heritability and does not have the mathematical limitations associated with FCR. RFI has little to no correlation with production traits and this indicates that genetic improvement of RFI within a selection index can be done without the confounding issues inherent with FCR. Improvements in RFI or FCR have a favourable effect on environmental emissions and decreases the environmental impact of poultry production. The current global production of ammonia, CH4, and N2O by the poultry industry is significant, at levels of 2.1, 29.44 and 279 million tonnes CO2eq, respectively. Reductions in emissions can be achieved via improvements in feed efficiency by lowering amounts of manure excreted and decreasing emitted by-products such as ammonia and greenhouse gases (N2O, CO2 and CH4). Consequently, improvements in feed efficiency can not only increase profitability of the poultry industries by lowering production costs but also decrease environmental impact by reducing environmental emissions.

Due to the high demands and production costs of the poultry industry it is imperative to study alternatives to modify the practice of incubation in order to maximise productivity by ensuring the conditions necessary for the development of embryos of current strains. Such changes in the management of incubation cannot affect the quality of chicks and broiler performance during early growth. To achieve these goals, several factors that work together during artificial incubation should be considered, for example, the relative humidity and turning machine incubators. Some research has already been conducted to define the optimum for these factors. This article reviews the results of studies where relative humidity and use of turning systems in incubators and their impact on incubation yield and chick performance were examined.

Broiler stunning is conducted to produce a rapid onset of insensibility prior to slaughter. Though most broiler plants use electrical stunning applications, gas stunning, and low-atmosphere pressure stunning are also available for commercial applications. All three of these stunning methods are able to meet animal welfare requirements and produce meat with acceptable quality. However, each method differs in their mechanisms of stunning, rigor mortis patterns, and physical meat characteristics. In addition, gas stunning and low-atmosphere pressure stunning have received interest over the past decade as part of an effort to further improve animal welfare. Researchers have reported that gas and low-atmosphere pressure stunning both have potential advantages over electrical stunning with respect to broiler welfare and deboning time, which has been attributed to shackling post-stunning. This review paper will focus on these three stunning methods and their impact on animal welfare, physiology, rigor mortis patterns, carcass characteristics, and meat quality.

Heat stress compromises performance and productivity through reducing feed intake, while decreasing nutrient utilisation, growth rate, egg production, egg quality and feed efficiency, leading to economic losses in poultry. High temperatures can lead to oxidative stress associated with a reduced antioxidant status in the bird in vivo, as reflected by increased oxidative damage and lowered plasma concentrations of antioxidants. Several strategies are currently available to alleviate the negative effects of high environmental temperature on the performance of poultry. However, as it is expensive to cool buildings in which animals are housed, many efforts are focused on dietary manipulation. In terms of reducing the negative effects of environmental stress, antioxidants are used in poultry feed because of the reported benefits of these supplements, including their anti-stress effects. In this review, the mode of action of these supplements is investigated, and evidence is presented showing that phytochemicals can alter several cell signalling pathways. The agents include epigallocatechin-3-gallate (EGCG; green tea), lycopene (tomato) and resveratrol (red grapes, peanuts and berries). The cell-signalling pathways inhibited by EGCG include transcription factors (nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)) and nuclear factors (erythroid-derived 2-like 2 (Nrf2)) and activator protein-1 (AP-1) that regulate cyclooxygenase-2 (COX-2). This review will also address some of the mechanisms proposed for the heat stress preventive activity of EGCG, lycopene and resveratrol focusing on the induction of antioxidant enzymes (phase II enzymes) through the activation of the antioxidant response element (ARE) transcription system.

Avian influenza is a highly pathogenic poultry disease found around the globe. It is caused by different strains of avian influenza virus. The H5N1 strain is not spread worldwide in humans, although, sporadic contaminations have been reported. It is known that the virus spreads from animals to humans however, there is concern regarding the evolution of the virus and that it is now possible for the virus to spread from human to human. There is currently no vaccine available that can act against all strains of the virus, although some vaccines have reached clinical trial stage. Regardless, there is a great need to develop a vaccine which will be effective against all strains of avian influenza. This review will focus on recent advances with special reference to the development of DNA vaccines against avian influenza. The specific importance, the hurdles to development and the possible future strategies for the development of DNA vaccines against multiple strains of avian influenza will be discussed.

Pakistan is an agro-livestock based economy with a poultry share of 55% of the total agricultural GDP (21%). The environment in Pakistan remains hot and humid during July to August, which renders the survival of poultry critical during these months, as birds are more susceptible to changing environments than other domestic animals. Heat stress is a combination of high environmental temperature and humidity, hindering proper thermoregulatory processes. It diminishes immunity, feed intake, weight gain, egg production, number of chicks per hen, hatchability of fertile eggs, egg and carcass quality, mineral balance, and increases panting and mortality and affects semen quality and fertility in male birds. Ascorbic acid (vitamin C), a white crystalline compound (also known as L-ascorbic acid) is primarily synthesised in the chicken by the kidneys, however, during heat stress, endogenous ascorbic acid becomes insufficient to meet the bird's requirements. Vitamin C ameliorates heat stress induced problems such as poor immunity, feed intake, weight gain, oxidative stress, rectal and body temperature, fertility and semen quality, carcass weight and mortality in birds.

This paper focuses on identification, risk status, exterior and production characteristics of two autochthonous hen breeds, the Banat Naked Neck and the Sombor Crested in the Republic of Serbia. These are two autochthonous breeds which have preserved the original characteristics of domestic poultry. Today they are reared in rural households or by breeders in small flocks. They mainly reproduce naturally, under brooding hens, with moderate attention or care from the farmer. These breeds are highly endangered. It is estimated that the total number of birds of the Banat Naked Neck breed ranges from 5,000 to 6,000 while the number of birds of the Sombor Crested breed is below 1,000. The limited number of birds per breed and the absence of experts and professional control in breeding have caused high variability of breed characteristics. These breeds are of combined type, used for production of meat and eggs; they have lower production characteristics, but are highly resistant and low-maintenance in regard to rearing and nutrition. To ensure the protection of these breeds from extinction, significant efforts have been made in the last decade. The preservation program has been developed for each breed in order to maintain the optimal number of animals to ensure a sufficient gene pool (by the ‘in situ’ conservation method), which could be used for the improvement of some traits in the selection of modern strains of poultry.

Climate change has already provoked a northward shift in the geographic range of many bird species, and current climate projections favour the modification of avian distributions and migratory routes. Given that wild birds are recognised as pathogen-dispersing agents, there is concern that changes in migrant ranges and movement patterns will increase the frequency of bird-borne pathogens reaching Northern areas, such as Canada. Furthermore, climate change will likely affect vector, pathogen, and reservoir ecology, which could contribute to changes in the range limits, the intensity of disease transmission and, under some circumstances, the risk of emergence and re-emergence of pathogens affecting commercial poultry.

However, the role of wild birds in the perpetuation of disease is unclear. Even if climate change increases the introduction of zoonotic and bird-borne pathogens into Canada, it is difficult to predict whether this will increase the occurrence of diseases in poultry. It is likely that outbreaks will become more unpredictable, which will complicate efforts to identify periods and areas of high risk. Efforts to manage and control these events in the face of climate change will require proper biosecurity measures, in addition to more consistent surveillance of sentinel and high-risk carrier species to avert the potential risk of diseases dispersing into Canada.

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.