Already we have the second issue of the Journal for 2018. Several topics are represented in this issue, including novel feed ingredients, minerals, antioxidation, choice feeding, welfare, human health products (eggs) and pathogen detection methods. In addition, we have an interesting review on enzymes, which reflects the recent talk given at the WPSA UK Spring meeting, held in Dublin, by Dr Mike Bedford on his receipt of the Gordon Memorial Medal – which is very well deserved. Dr Bedford is well known in the poultry world for his extensive and pioneering work in the world of enzymes, and I have been privileged to work with Mike over the years, going back to my early commercial work at Finnfeeds International in the 1990s. He is an exceptionally able scientist, never afraid to confront technical challenges or to look at problems in new ways, as well as being an approachable and friendly face in the industry. Congratulations to him, and to his lovely and supportive wife Linda.

There are many events coming up in 2018, including the excellent Hafez turkey meeting in Berlin, the 6th Mediterranean Poultry Summit, both in June, the PSA (with the US WPSA branch meeting) in San Antonio in July and the 25th European Poultry Conference in Croatia in September, where the next WPSA board meeting will be held. Various branch meetings are happening, and full details can be found on our website (www.wpsa.com). Do please support these events, as they not only provide useful and interesting scientific sessions, but also provide a great networking opportunity.

One issue that is becoming more prominent for all journals is the future of publishing peer reviewed papers. This is something that has changed greatly in recent years, and continues to change, especially with the advent of open access. This is something that is being discussed in all spheres of publishing, as the costs of open access are still high and have to be borne by authors. The WPSJ is in a strong position, as it does not charge submission charges to authors, making open access rather more affordable for authors. All papers are eligible for open access – details of which are on the submission website. In addition, we are seeing a shift in regional souring of the papers submitted, which is something that needs to be addressed to keep the journal content balanced, and which I am focussing on. For anyone who is interested in publishing a review, but perhaps needs some assistance or advice, do feel free to email me with your idea or draft. The editorial office is happy to help young or new authors get their work out in the public domain.

Dr Lucy Waldron

Editor

We are already at the December issue and 2018 seems to have flown by in a flurry of editing papers and conferences. As always, the WPSA branches and federations have been very active in organising conferences and meetings. As well as the usual well organised branch meetings, there have been some memorable events, including the very well attended EPC meeting in Dubrovnik. This was an excellent meeting in a superb location, and congratulations to the organisers, especially when dealing with the oversubscription from delegates. It’s good to see members supporting WPSA events around the world – not only for the dissemination of new science but also for the networking opportunities it provides. The good news is that the impact factor for WPSJ has increased by 40%, up to 1.493, and our five-year IF is now up to 1.682. This ranks us up to 18 out of 60 for all agriculturally related journals – a great achievement for which I would like to thanks all of the team, and the board members (especially Dr Zehava Uni) suggestions for changes to the summaries that appear to have driven this increase.

It was with sadness that I edited the obituary section for this issue. We have lost some major poultry names in the last few months, some of whom were great friends of mine and who I had worked with over the years, and were notable poultry personalities. Dr Paul Hockings review in the WPSJ and proposals for foot pad lesion scoring is still majorly cited, and remains a great piece of work. On a happier note, it was lovely to see Dr Peter Hunton being honoured for his work in poultry. Peter has been a very long term WPSA supporter, as well as serving his branch and the global body in several important roles. A personal thank you from me for all your past and current efforts, Peter.

Some issues have been raised recently about the ease of accessing the online version of the journal and via search engines, such as Google Scholar, Pubmed and Web of Science. If you personally have had problems with this, please let Dorien Kleverwal in the Dutch office know, so WPSA can get this amended to make finding papers quick and easy. Do not forget, when you apply for online access, you can request emailing for papers which contain the key words that match your personal scientific interests. This means that you will be emailed directly with links to those papers that are relevant to your work.

We need to look towards 2019, as this is the last issue of 2018. As I write, we are already finalising the March issue, and please, for all those authors who write to me two weeks after submission requesting publication information, note that the journal is typically running 6 months ahead of time regarding issues being published. At the recent meeting in Dubrovnik, it was decided by the Board that Taylor and Francis (based in the UK) will take over the publishing of the journal at the end of 2019. This is due to Cambridge University Press divesting their applied science journals and focussing on pure science publishing. WPSJ is not the only journal affected and it is nothing to do with our relationship with CUP which has, for me, been an enjoyable experience working with some very good people. For submitting authors, there should be no discernible changes, it will be business as usual, and there is already a plan in place for the hand over. It will mean more work for me in 2019, but I am confident that, with the assistance of board members (Drs. Bob Buresh, Werner Bessei, Roel Mulder and Zehava Uni, who have been appointed to this task) all will go well. We will also be revamping the editorial board in a more active role, and I will confirm the appointments after our initial meetings to organise this in 2019.

Meanwhile, it remains for me to wish all our readers and members happy holidays and seasons greetings, wherever you are in the world.

Dr Lucy Waldron

Editor

The first issue of the year and already we have finalised the June issue with the amount of papers coming in. In this issue we have papers on lighting, uniformity of flocks, trace minerals as well as specialist and novel ingredients. This year sees the preparation of the 2020 WPC in Paris kicking off, which looks to be an excellent programme and all-round experience, both academic and commercial. Issue around the world are increasingly focussed on the limitation or removal of antibiotics in those countries that have not yet done so, and hence the increasing importance of biosecurity on farm for maintaining poultry health and welfare. The industry globally has had to adapt to many changes in regulations and many countries have already gone a long way in their examination of more consumer acceptable alternatives to traditional prophylactic measures – which should make it easier for those regions making the transition now or in the near future. My invitations to speak at various conferences and workshops in China last year where they are bringing in restrictions on growth promoters in feed has highlighted this well, as they come into line with the rest of the world in terms of what retailers and consumers require in poultry production as well as controlling pollution from excretion. Registering alternatives to growth promoters, e.g. plant extracts, will require new regulatory processes in various countries.

This year sees several major conferences being hosted, including the fabulous Hafez turkey diseases meeting in May, which I can highly recommend, especially the conference dinner and belly dancers. September sees the 25th European Poultry Conference, being held in Croatia, which is also the venue for the global board meeting – and I will be hosting the editorial meeting there as well and hope to catch up with colleagues and friends. Other commercial and regional meetings are already listed on the WPSA website – please check it out and attend as much as you can to support regional branches and the larger meetings, as the organisers put a lot of effort and time into staging these events.

The editorial office would like to wish all readers and members and happy (if belated) and prosperous 2018 and look forward to seeing you at meetings. Keep the papers coming!

Dr Lucy Waldron

Editor

September sees the European Poultry Nutrition Symposium being hosted in the beautiful city of Dubrovnik, and I hope to see many members attending the conference. The WPSA will be holding their annual board meeting just prior to this event, as are other allied associations, taking advantage of the availability of delegates to attend other meetings as well as the sessions. So, if you haven’t already registered, please show your support for the organisers and the sponsors by doing so.

The current issue of the WPSJ includes papers covering topics related to nutrition and specialist feed ingredients, disease and vaccination, laying hens and egg production, reproductive physiology and a comprehensive review of performance factors. The increase in reviews regarding alternatives to antibiotics continues unabated, due to the impending bans for in-feed disease control expected across countries outside of the EU in the next few years, and in the editorial office we are expecting this trend to continue. Human disease from consumption of poultry meat remains a headline-grabber in the popular and academic media, and the industry is very proactive in putting control measures into place, even when the main issue of gastroenteritis in humans is, in reality, a problem from red meat and poor hygiene in the kitchen, as previous WPSJ reviews have ably demonstrated. Other pertinent issues in the poultry world include welfare and animal care – and we always welcome more review papers on these topics from authors – so please send them in.

Again, and I know I have mentioned this before, all authors need to ensure their summary is a true summary of the findings from their review, including average doses, responses, benefits etc. The summary is the first point of contact with people searching online for relevant papers and information. If they are not members, then they can only see the summary, so this must be comprehensive in order to maximise downloads of the complete papers or citation based on the summary. All journals are graded by their impact factor, which is calculated from the number of times a paper is cited in one year after publication or as a five-year average. To keep our impact factor competitive, maximising information from summaries is essential.

Dr Lucy Waldron

Editor

Macroscopic algae can be found in large open ponds or harvested from the sea. Macro algae includes three distinct groups based on colour: green, brown and red. They are unique in containing secondary metabolites that can be extracted and used for various purposes. This review examines the antimicrobial properties (bacteria, viruses and fungi) of macro algae and its extracts to improve poultry health and performance. This includes body weight gain, feed conversion efficiency and carcass yield improvements in broilers and egg weight and shell quality in layers. As an example, in one study, 35-day body weight of broilers was increased 7.6% with the inclusion of 0.5% Undaria pinnatifida (brown macroalgae) to the diet. The investigations discussed show the diversity of the species available and broad scope where research has been done and the potential for the future.

China has been the world's largest producer of eggs for the last 30 years. There have been considerable recent changes in the structure of the egg industry due to rapid economic growth, improved supply chains and favourable prices. Since 2012, revenue from poultry has increased by 8.7% on average. Annual growth rate of egg production has been approximately 0.6 million tonnes per year from 2000 to 2016 (FAO, 2017), and 2016 saw the total eggs produced reaching a peak of 31 million tonnes. Egg production in China continues to provide the population with a significant proportion of their intake of high quality dietary protein. Egg consumption is expected to continue to increase with the rise in the urban population. It is probable that the highest increase in demand for eggs will be for ‘out of home’ consumption and in processed food products. These levels of production are associated with the spread of intensive systems. The poultry sector is no longer dominated by hundreds of millions of smallholders keeping birds as a side-line activity and many small farmers have ceased production. Chinese consumers are becoming more focused on the quality and safety of eggs. Future developments in the egg production are expected to concentrate on quality, safety and traceability of eggs.

The concentration of vitamin A in egg yolk is directly related to its inclusion in the diet of laying hens. The vitamin A concentration of the egg yolk is 79 µg/100 g or 263 UI/100 g, and the concentration in 60 g eggs increased from 59 to 75 µg in response to an increase in dietary vitamin A supplementation. Currently, the level of vitamin A recommended for laying hens is 900 UI/day or 9,000 UI/kg feed and 15,000 UI/kg of egg mass. The bioavailability of preformed vitamin A in the egg ranges from 90 to 100%, accounting for about 15% of the daily recommended dietary intake for humans, while bioavailability may vary from 10 to 67%. The table egg is a functional food for humans that can be enriched with vitamin A, and its consumption could be an alternative to prevent and reduce the prevalence of deficiencies, especially in risk groups, such as children and the elderly.

Glutathione peroxidase (GSH-Px) was described as a selenoprotein in 1973 and, since then, a great body of information has been accumulated to validate its important role in the antioxidant defence network in all animals, including poultry. The GSH-Px family includes at least eight members, and four of them (GSH-Px1, GSH-Px2, GSH-Px3 and GSH-Px4) are shown to be selenoproteins in animals. They are characterised by species- and tissue-specificity in their expression and activity. An optimal Se status in tissues/body is key for maximum expression of GSH-Px and therefore, in avian research GSH-Px activity is widely used as a biomarker for determining Se status and requirements. On the other hand, GSH-Px is an inducible enzyme and its activity depends on the level of stress and can be used as an index of antioxidant defences. In poultry production two forms of Se-dependent GSH-Px (GSH-Px1 and GSH-Px4) have received most attention. The aim of this paper is to review GSH-Px properties and functions in relation to poultry biology with special emphasis to its role in chicken adaptation to various stress conditions. Recent advances in selenoprotein identification and characterisation in relation to poultry Se status, dietary sources of Se and stress conditions can shed light on the roles of GSH-Px in avian biology.

The presence of certain mycotoxins within poultry feed has a negative impact upon the growth and the quality of the final product in the form of meat and eggs. More than 300 different chemically diverse mycotoxins have been identified, but ochratoxins and aflatoxins are considered to be most harmful to the poultry industry. Ochratoxin, more importantly ochratoxin A (OTA) is produced by different species of Aspergillus and Penicillium spp. which are present as storage fungi within the stored grains and feed ingredients. Body weight gain has been found to decrease in a dose dependent manner when infected at rates of 0.5-29.4 mg/kg for 7-60 days in different experimental studies. Decreased feed intake has been observed at levels of 0.5-4 mg/kg OTA fed for 21-60 days, while egg production, hatchability, eggshell thickness and egg mass production is severely affected when 0.5-4 mg/kg OTA in feed was fed for 28-84 days. However, 0.5-20 mg/kg OTA given for between two and 10 weeks of age was sufficient to produce histopathological alterations in the liver, kidney, thymus, bursa of Fabricius, spleen, lungs and heart. The research shows that OTA adversely affects every organ in birds and, in the following review, OTA associated alterations in growth parameters, production performance and histopathological disturbances of different body organs are discussed.

Conventional feeding systems for laying hens rely on a complete feed available ad libitum in mash, pelleted or crumble form. When complete feeds are used, intake is mainly controlled by the hens’ energy requirement and feed presentation, but the birds cannot adjust their consumption to other nutritional needs and thus over-consume to cover the calcium needed for egg shell formation. Sequential, loose-mix and choice feeding offer birds the opportunity to select different diets in the short term. These feeding strategies have been proposed as alternative feeding systems whose main objectives are to match nutrient supply to individual requirements during the daily changes induced by the temporal sequence of the egg formation. This review discusses some findings related to the use of whole cereals and of alternating low and high energy or protein diets, conditions which may improve feed utilisation efficiency. In addition, the adjustment of calcium and phosphorus levels during the day can have benefits in terms of egg production and quality. This review explores the physiological basis for sequential, loose-mix and choice feeding and evaluates the impact of these systems on egg production and quality.

Poor uniformity in a broiler operation reduces revenue and increases waste. Uniformity in body weight at harvest is influenced by variation in genotype, environment and feed composition and form. Variation in growth in broilers within each sex is usually relatively small, but increases markedly when a poor quality feed is given. In attempting to grow to meet their potential when fed a diet low in protein, birds need to overconsume energy and then release excessive amounts of heat to the environment, although this ability is constrained by both feather cover and the ability to fatten. Consequently, as broiler genotypes have become faster growing and leaner, there is an increased need to feed higher levels of balanced protein in a cooler environment as a means of improving uniformity. Separating the sexes and reducing the range in day-old body weights will assist in achieving better uniformity at harvest.

This review provides a synopsis of nutritional strategies used to improve the efficiency of feed efficiency (FE) of broilers at a given nutrient density. A small reduction in feed intake can improve FE as a function of improved nutrient digestibility and or post-absorptive metabolism. Restriction of nutrient intake to slow down growth during the mid-growth period followed by reinstatement of conventional feed afterwards, may lead to compensatory growth and improved FE. Replacement of part of the dietary starch with a slowly digested starch source has been shown to help improve growth performance and FE, perhaps by sparing amino acid catabolism by enterocytes, and/or through more synchronised uptake of glucose and nitrogen by the systemic circulation. Development of a larger, more functional gizzard, through provision of feed with coarser particles or structural fibre has been shown to improve digestibility and efficiency of nutrient utilisation. Although broilers are often fed pelleted diets which achieve better growth performance than a mash counterpart, the particulars of the process, including pellet quality, pelleting temperature, and particle size within pellets are important determinants of the magnitude of the pelleting response. Use of the high doses of phytase, often referred to as phytase super-dosing, targeting more complete phytate destruction have been shown to improve FE of broiler fed commercial diets. It can be speculated that combined use of these strategies could potentially help improve FE by between 8 to 10 points (0.08-0.1).

Animal welfare has become an important issue in poultry production. Concern about poultry welfare has mainly been expressed in industrialised countries. Since trade of poultry products is highly internationalised, welfare aspects have to be considered by all countries involved. This paper reviews the changes in the attitude to animal welfare in Western societies and the related development of regulations and standards, the impact of high welfare standards on production costs and on international trade of poultry products and finally, the influence of different stakeholders on poultry production and marketing. From the 1960s onwards, animal welfare activities have been focused on farm animals kept under ‘industrial’ conditions, such as caged laying hens. Consequently, the management conditions for laying hens in Europe have been regulated in detail by national laws and EU-Directives. Meanwhile, conventional cages have been banned in the EU and welfare activities are now directed towards other issues, such as beak-trimming and killing day-old chicks of layer lines. All measures which are considered to improve the welfare of animals increase cost of production. Hence, differences in national welfare regulations are expected to relocate poultry production to countries with low welfare standards. There is a tendency that important retailers and food chains use welfare as a marketing argument and establish high price premium labels. Standards which are established and controlled by stakeholders of the poultry market are independent of national welfare legislation. This will lead to harmonisation of welfare standards on an international level. Most welfare labels have been developed by retailers in cooperation with welfare-oriented NGOs. There is a new trend in Germany where retailers and farmers organisations develop welfare schemes and poultry producers are paid an extra allowance for welfare-friendly production. This system ensures that poultry farmers are reimbursed for the welfare-related costs.

In birds, after natural mating or artificial insemination (AI), sperms are transported through cloaca or vagina at the utero-vaginal junction (UVJ) of oviduct. Only 1% of the deposited sperm passes through the selection process in the vagina to reach the UVJ. In the UVJ, sperm enter the tubular invagination of the surface epithelium of the mucosa collectively called ‘sperm storage tubules’ (SSTs) where they are stored for longer duration retaining their fertilising capacity. The storage capacity and duration varies from species to species. This enables the birds to produce fertile eggs continuously. Shortly before and during egg production, sperm residing in the SST upon release will ascend the oviduct to the site of fertilisation in the infundibulum. Within the SSTs, sperm motility is suppressed and is initiated at some stage before fertilisation. Restoration of sperm motility is necessary for the release of spermatozoa from the SSTs. The exact mechanism by which sperm are stored in these tubules and released has not been established and hence, this is the focus of this review.

Agroindustry wastes from tomato, olive, date and sunflower processing have valuable nutritional characteristics, and could be included in poultry rations to facilitate reducing feeding costs. By-products of tomato and olive processing can be supplemented in the diet of broilers and laying hens by up to 10% without detrimental effects on production, whilst improving the biochemical blood profile and enhancing the oxidative status of birds. Published research has shown that feeding sunflower and date wastes could be successfully added to diet at high inclusion levels (up to 30 and 40%, respectively) resulting in heavier broiler carcasses and increased number of eggs produced by laying hens. In this paper, applications of agricultural wastes and by-products in poultry feeding is reviewed, and the documented and novel findings related to their influence on poultry production, health and gut microbiota are discussed.

High ambient temperatures affect animal production and welfare in tropical and sub-tropical regions of the world. Feed intake, growth rate, mortality, egg production, hatchability and other production traits related to the economic success of the poultry industry are adversely affected by severe heat stress. In general, heat stress induces the activity of the neuroendocrine system, resulting in activation of the hypothalamic-pituitary-adrenal (HPA) axis, and elevated corticosterone (CORT) concentrations, which affects metabolism and immune responses. These include negative regulation of metabolic hormones, antibody production and heterophil to lymphocyte (H/L) ratio. Heat stress increases mitochondrial activity, causing reactive species overproduction which disrupts the antioxidant balance, leading to oxidative stress damage of membranes, protein and DNA. Heat stress stimulates the central nervous system (CNS), which significantly reduces daily gain, feed intake and FCR in poultry. Consequently, from an animal husbandry perspective, intervention strategies to relieve heat stress conditions have been the focus of many published studies. This review describes the effect of high temperature on production, behavioural, biochemical and immune responses, including oxidative damage that occur during heat stress in poultry, in broilers and laying hens. Moreover, nutritional interventions to alleviate the negative consequence of heat stress is discussed.