As many of you will have seen, the 2016 World’s Poultry Congress in Beijing is gearing up – with abstracts in and preparations underway. Our association news contains more information on this – the organisers have been sorting out cheaper ways for attendance and there are prizes up for grabs for students, so do check out their website. The Board will be having their annual meeting there as well – which is a good time to catch up with all the reviewers and editorial board members who we rely on heavily for support of the journal – many thanks to all of them.

I do hope many of you have been receiving papers via FirstView – which publishes papers online as soon as they are finalised in the editorial office. We have more papers than ever to process, so if you have delay in your review coming out please bear in mind we operate typically six months ahead in terms of final publishing from final approval. I have recently returned from publishers meetings in the UK and attended the WPSA UK conference in Chester as well – where we held a memorial for Prof. Gordon Rosen, who sadly died last year. The conference dinner was followed by a very well attended drinks party held in the bar (as Gordon would have approved of) with his widow Mrs. Vanda Rosen present for the WPSA dinner as well as the celebration of his life. I have never been at such a memorial gathering before and many people came and said lovely things about Gordon. Several speeches were made regarding his wonderful character, sense of humour and attitude to precision in poultry science. Mention was made of his tendency to be the ‘sweet old man’ in the front row of conferences who delivered killer questions to the unwary! I know Vanda would like to thank the organisers, especially Dr Mike Bedford, Dr Emily Burton and Dr Vicky Sandilands and the UK board for their assistance in organising such a great event.

We have had another sad loss of an excellent poultry scientist; Ir Douwe Arnold Ehlhardt in the Netherlands recently passed away (see obituary). His contribution highlights how much was done by scientists in the past to not only to progress poultry production, but also to change how poultry are raised to come into line with modern needs.

However, as always, science moves on and we have an excellent program of WPSA related symposia during the year. Please do support these events and their sponsors, as without the latter we could not keep up the essential discussion between business and academia.

See you all in China!

Dr Lucy Waldron

Editor

Several techniques are available solely applicable to the study of inevitable endogenous flow or the digestibility of amino acids (AAs) at the terminal ileum. But the linear regression technique combines these tasks in one simple and flexible platform extendable to multifactorial evaluation of feedstuffs, for example under alternating dietary and physiological conditions. There is evidence that the amount and composition of inevitable endogenous flows are not constant. Also their estimates are dependent on assay protocols and other laboratory conditions. This variability is a drawback to methodological precision of the current conventional standardised digestibility (cSID) system, where inevitable endogenous flow is applied to correct apparent digestibility. Notably cSID may suffer systematic errors when used to assay low AA ingredients or those high in AAs and in anti-nutrients, leading to underestimation or overestimation of standardised digestibility, respectively. Thus a standardised system not encumbered by the need to determine inevitable flow should offer more latitude for precision. The latter approach is followed in linear regression. The linear regression approach is based on validated hypotheses both mathematical and physiological, which enable its ordinate intercept and slope respectively to be considered as inevitable endogenous flow and standardised digestibility. The literature shows that this method does not penalise ingredients low in AAs as its estimates are independent of dietary crude protein level; and it is efficient to determine standardised digestibility in feedstuffs which elevate the production of specific endogenous ileal AA flow. Nevertheless work remains to be done to standardise its protocols to improve comparability of data across investigations. It can be concluded that linear regression is a reliable path for routine determination of inevitable endogenous flow and standardised AA digestibility at the end of the ileum.

The effect of sodium butyrate on various bodily parameters of broilers such as performance, gut microflora, gut morphology, and immunity is reviewed in order to highlight its importance as an alternative to antibiotic growth promoters. Sodium butyrate is used as a source of butyric acid, which is known for its beneficial effects in the gut in monogastrics. Sodium butyrate is available in uncoated and enteric-coated forms protected with fat or fatty acid salts. Varying results in productive performance, gut microbes, and gut morphology have been reported in the literature in response to supplementation of broiler diets with uncoated and fat-coated types of sodium butyrate. However, sodium butyrate has shown pronounced effects on immunity of chickens that are not fully understood yet. Although there are contrasting results of sodium butyrate in chicken, further research is needed using the sodium butyrate coated with the salts of fatty acids.

The importance of feed particle size, as a tool to optimise the utilisation of feed and improve production efficiency in broilers, has attracted increased attention in recent years. Particle size reduction is widely believed to enhance the access of digestive enzymes to substrates because of the increased surface area of feed particles. Fine particles can negatively affect the development of fore-gut (proventriculus and gizzard), which plays an important role in intestinal health and nutrient utilisation. A well-developed fore-gut can be achieved by feeding coarse particles which is associated with improvements in gut motility and health. However, the results of studies considering the effect of feed particle size on upper gastrointestinal tract development have been inconclusive, because of the confounding effects of feed form (mash vs. pellets). Feed particle size influences the development of gastrointestinal tract and bird performance to a greater extent when the broilers are fed mash than pelleted diets. Particle size-reducing properties of the pelleting process may result in suboptimal gizzard development and changes in the intestinal morphology and microbiota profile.

Due to exposure of animals to numerous stress-inducing factors and a high level of cellular metabolism resulting from the conditions and manner in which they are raised, destabilisation of the redox balance towards excessive activity of free radical species is a common phenomenon. Enhancing the antioxidant status of the animal organism by optimising the level and quality of feeding, and especially by supplementation with exogenous antioxidants, may be one essential and highly effective means of improving the health and thus the productivity of animals. Natural plant supplements in diets for poultry can be used to enhance antioxidant defence mechanisms and reduce the intensity of oxidation processes, which negatively affect the quality of poultry products, i.e. meat and eggs. Analysis of the available studies shows that antioxidant processes in the organism of birds can be stimulated via administration of extracted active compounds, among which the highest antioxidant activity is found in resveratrol, hesperidin, genistein, thymol and carvacrol, and herbs, for example from garlic, aloe vera, oregano and rosemary.

High ambient temperature is associated with decreasing growth rate, egg production, feed efficiency, nutrient utilisation, egg quality and is a major problem resulting in extensive economic losses in poultry. Poultry reared under heat stress may exhibit various metabolic disorders caused by a chronic state of oxidative stress and inflammation. Recently, nuclear factor-erythroid 2-related factor 2 (Nrf2) has emerged as an agent that plays a significant role in cellular protection against oxidative stress and inflammation. The nuclear factor kappa-B (NF-κB) signalling pathway has been associated with enhanced inflammatory response and its activation has been significantly correlated with heat stress. These transcription factors when activated can regulate antioxidant and anti-inflammatory cellular responses leading to the expression of detoxifying enzymes. Studies have shown that NF-κB and Nrf2 expression can be modulated by several factors, such as bioactive compounds. Green tea contains many polyphenolic antioxidants including the catechin, epigallocatechin-3-gallate (EGCG). As bioactive compounds, supplementing EGCG in poultry diets may improve antioxidant status in poultry. EGCG modulates signalling pathways including the NF-κB and Nrf2 that regulate antioxidant and anti-inflammatory responses. This review aims to discuss the evidence to justify a recommendation of EGCG in heat stressed poultry as a non-pharmacological option to activate the NF-κB and Nrf2 pathways.

Soybean meal (SBM) remains the most important and preferred protein feed source for poultry. However, the supply and quality of SBM fluctuates, and the meal is expensive due to processing and transportation costs. Although there is a growing interest in the use of raw SBM for birds, its nutritive value is negatively affected by the presence of anti-nutritive factors (ANF). Heat treatment is applied to alleviate some ANF, such as trypsin inhibitors and lectins, but both under- and over-processing of soybeans can reduce the digestibility of key components in the meal. Feed supplementation with exogenous enzymes, such as phytase and protease enzymes, is a biotechnological option for improving the nutritional values of SBM and other protein-rich ingredients. Proteases break down both stored proteins and proteinaceous anti-nutrients in feeds. Various studies have shown that the performance of birds can be improved through dietary supplementation with new-generation protease enzymes. Phytase is also effective in breaking down phytate (phytic acid), which chelates with mineral cations and other nutrients in soybeans. Recent in vitro and in vivo studies have shown that an enzyme cocktail (combined use of protease and phytase) is more effective in reducing ANF in soybean meal for birds than the use of single enzyme products. This review provides information on how microbial enzymes, particularly protease and phytase, contribute to the improvement of the nutritional values of different types of SBM for poultry.

The shell colour of the eggs laid by pheasants is determined genetically and can vary from very light to dark brown. In general, four basic colours may be distinguished: dark brown, light brown, olive, and blue. A number of studies indicate that there is a relationship between the colour of pheasant eggshells and their quality. Pheasant eggs with different shell colours differ in terms of morphological (shape) and physical features (weight, egg specific gravity, yolk and albumen share and indices) as well as eggshell quality (thickness, strength, ultrastructure). Studies conducted by previous authors demonstrated a range of structural and physical properties of pheasant eggs. The microscopic structure of the blue-coloured shells demonstrates some abnormalities in the structure and thickness of the shell layers and the shells of these eggs are the thinnest. This may be the cause of poorer hatchability in blue-coloured shell eggs.

Confinement housing appears to be at the forefront of concern about farm animal welfare. Although many factors may affect the welfare of commercial laying hens housed in cage and non-cage systems, welfare issues in confinement systems often involve behavioural restrictions, while many welfare issues in more extensive systems involve health and hygiene. Hens require an absolute amount of three-dimensional space in order to be able to perform basic body movements. They may prefer to distance themselves from other birds, but their strength of motivation to do so has not been thoroughly investigated, and preferred inter-individual distances may vary with activity. The relationships between the effects of space and group size on behaviour are not well understood, particularly in large groups where birds may cluster together around resources and at different times of day. There are common risks to hen welfare posed by both cage and non-cage systems such as overcrowding. However, some welfare issues present a greater risk in one system compared to another. When considering space and social environment, the comparison of cage and non-cage systems must take into account the threats to welfare that are specific to each system. Furthermore, this review highlights the importance of the design of the housing system rather than just the housing system per se.

In Pakistan, H9N2 avian influenza viruses were first reported in 1998, and since then, they have been prevalent in chickens and have continuously evolved through reassortment in live bird markets. Poultry carrying H9N2 viruses act as incubators for the evolution of influenza viruses in wild birds. Recent reports have shown that the Pakistani H9N2 viruses have undergone antigenic drift and evolved into novel genotypes posing a potential threat to poultry and human health having genome segments similar to H5N1 and H7N3 viruses. Recent evidence of interspecies transmission suggested that the H9N2 avian virus could be the next human pandemic strain. Continuous monitoring of viral evolution and updates on vaccines are warranted to achieve efficient control and eradication of H9N2 viruses in Pakistan. The following review covers the emergence and evolution of H9N2 viruses and vaccination strategy in Pakistan.

Much of the dark meat from U.S. broilers continues to be exported to other countries because of local consumers’ long-standing and strong preference for white breast meat. In this review we will discuss what causes meat colour differences and how environmental and genetic factors influence the colour of poultry meat. It is well documented that the darker colour of leg/thigh meat is due to the larger amount of myoglobin and haem pigments, as well as a higher pH when compared to breast meat. Slaughtering older birds increases myoglobin content in the meat and selection of breeds for greater breast meat yield may be involved. Using a wheat-based diet tends to lighten the colour of breast meat but has less effect on the thigh meat. Several antimicrobials used in further processing can lead to either bleaching or a reddening of the meat. Changes to colour using chemical or physiological methods are theoretically possible, however may not be great enough to improve consumer acceptability. From a marketing perspective, increased media promotion of dark meat as being equal to white meat in healthiness and superior in flavour may have the greatest effect on increasing sales.

The gastrointestinal tract is a large reservoir of both Gram positive and negative bacteria, of which the Gram negative bacteria act as a source of lipopolysaccharide (LPS). Luminal LPS, commonly known as endotoxin, can enter systemic circulation via paracellular and transcellular permeation. It has been shown that endotoxin exposure can increase intestinal paracellular permeability and alter intestinal structure and function, resulting in impaired absorption and utilisation of nutrients with negative impact on both poultry heath and growth. Acute exposure to large amounts of endotoxin suppresses feed intake in chickens and activation of the innate immune system. Substantial evidence suggests that endotoxin is recognised via toll-like receptor (TLR)-4, located on the surface of immune cells, which activates kinases to enhance the transcription of pro-inflammatory cytokines such as tumour necrosis factor alpha (TNF-α) and interleukin (IL)-1 and 6 which mediate the inhibitory effect of endotoxin on the intestinal nutrient absorption. Inflammation can divert energy and nutrients away from growth supp and into supporting the immune system responses, leading to growth suppression and lowered feed efficiency. In addition, sustained exposure to endotoxin may elicit tolerance, which can make animals refractory against secondary Gram-negative infections. In this review, the effects of endotoxin on intestinal barrier functions and the subsequent negative impacts on the production of chickens are summarised. Overall, this review combines the current knowledge of the chicken's intestinal responses to Gram negative bacterial infection, illustrating the importance of gut health in defence against bacterial infections and improving poultry health, growth and welfare.

Poultry is frequently colonised by and constitutes a natural reservoir for Campylobacter spp., primarily C. jejuni and C. coli. Infection with C. jejuni is a leading cause of food borne gastroenteritis in humans worldwide. Prevalence rates in poultry are variable and can reach as high as 100% on some farms. Campylobacter spp. are commensal organisms that establish persistent infections which produce little or no overt disease in the avian host despite extensive colonisation. Although campylobacteriosis is insignificant for poultry health, contaminated poultry meat is recognised as the main source for human exposure. An alarming recent trend is the rapid emergence of antimicrobial resistant Campylobacter spp. strains all over the world. Colonisation can persist for the lifetime of the animal, consequently leading to carcass contamination at the slaughter facility. Therefore, considerable research efforts have been devoted to the development of interventions to diminish contamination in poultry, with the intention to reduce the burden of food borne illnesses. During the past decade, significant advances have been made in understanding Campylobacter spp. in poultry. This review summarises the currently available information about the infections in poultry. Secondly, it addresses the colonisation, risk factors and current challenges of Campylobacter spp. in poultry. Finally, immune intervention and the future prospects of vaccination for the control of Campylobacter spp. in poultry are discussed.

This paper is an applied case study of production optimisation in case of pâté production in Slovenia. Pâté production within the poultry industry is performed on modern high speed fully automatic production lines. These have large capacities, and technical efficiency is crucial since it as a large impact on production costs and profitability. In this paper the results from empirical research on the technical aspects and costs efficiency of pâté production by using overall equipment efficiency (OEE) and overall cost efficiency (OCE) framework is reviewed. The data shows significant reserves which are favourable for using OEE - OCE methodology as daily tools to monitor production management.

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.

With great sadness we have lost a good friend and scientist. On February 1, 2016 Ir Douwe Arnold Ehlhardt passed away in a hospital in Amsterdam at the age of almost 80 years. Douwe, born in Leeuwarden on February 18, 1936 graduated at Wageningen University in 1961. After completing his military service, he started in 1963 his professional career at the Cooperative Poultry Breeder Institute (CPI) in Nuland. Here Douwe became secretary of the scientific breeding committee to advice members of the layer breeder’s cooperative on genetic selection issues.

In 1971 Douwe became senior scientist at the Spelderholt Centre for Poultry Research in Beekbergen with a special focus on turkey research.

Following the fast increase in broiler meat consumption during the sixties it was believed that turkey meat consumption would follow the same trend. This made Douwe to decide to visit Prof Karl Nestor in Wooster (Ohio). In 1972 he went to the USA and worked together with Prof Nestor at his institute to improve his knowledge on breeding, hatching, feeding, housing and disease control of turkeys.

Back in The Netherlands, Douwe became secretary of the Dutch Branch of WPSA, which position he held until 1977. In that year he went for two and a half years with his family to Naivasha in Kenya where he, on behalf of the Dutch Government, built an applied poultry research station. After returning to The Netherlands Douwe was asked to become secretary of the European Federation of WPSA, a position he accepted in 1981 and remained in until 1993. During these twelve years he was involved with the organisation of the 7th European Poultry Congress in Paris (France) in 1986 and the 8th European Poultry Congress in Barcelona (Spain). A few months after the congress in Paris, Douwe received the ‘Chevalier de l'Ordre du Mérite Agricole’ during a special event at the Spelderholt Centre for Poultry Research. This high decoration, handed over by the French Ambassador in The Netherlands, was given to Douwe because of his great contribution to the conference.

During the eighties the Dutch poultry industry received increasing numbers of public comments on how layers were held in cages. Animal protection groups and activists fought for animal rights. Following many difficult discussions between poultry behaviour scientists in the governmental Spelderholt Centre for Poultry Research, animal protection people and governmental officials as well as politicians, Douwe Ehlhardt initiated research on keeping birds in the aviary system. He had to solve many issues including cannibalism, handling manure (including nitrogen emissions), in-house climate conditions as well as preventing floor eggs. Since then most of these problems have been resolved and, following the ban on layer cages in 2012, provide layer farmers an opportunity to keep layers efficiently in non-cage systems. Today more than 80 % of the layers in The Netherlands are kept in aviary systems.

In 1993 Douwe was asked by the Dutch government to lead a poultry development project in Saudi Arabia. He accepted the offer and spent two years in Riyadh at the Ministry of Agriculture solving poultry husbandry problems in Saudi Arabia. In 1995 he rejoined Spelderholt but had to move to Lelystad when research activities on ruminants, pigs and poultry were concentrated in one research institute called ID-DLO. He worked there till his retirement in 2001.

Ir Douwe Ehlhardt contributed a great deal to poultry research in The Netherlands and worldwide. We have lost an integral scientist, a friend to his colleagues and fellowworkers and a man who, due to his language skills, made people laugh. We will sadly miss him.