Well it’s been a busy year – increasingly so due to the volume of papers being submitted to the WPSJ online. It appears that our little journal goes from strength to strength, attracting more authors all the time, which is very good news for us in the office as well as for our members. As I’m writing this well in advance, by the time the September issue appears, we have already passed some milestones of 2012, including the Brazilian World Poultry Congress in August. It looks to be a very exciting event, well represented at a scientific and a trade level. Congratulations to the organisers – it’s hard work getting such a large and prestigious event co-ordinated.

For all of you on the editorial board – I’d like to thank you in advance for your attendance and contributions in our WPC meeting. Sometimes it can feel a bit isolated being an editor – as you are often several degrees removed from those writing the papers – so it’s always rewarding to meet authors at scientific meetings. Of course the WPC marks a new WPSA President, and the outgoing of the previous incumbent. I’d like to take this opportunity to thank Dr. Bob Pym for all his help and support with the Journal during his years as president. He has performed his role very well in my opinion, and has even contributed a centennial paper for us in this issue.

I do hope you enjoy this issue – we have plenty more paper stacked up into 2013 to be getting along with, and the Journal continues to progress in terms of variety as well as numbers of papers. Please make us your first port of call for any reviews you may have.

Dr Lucy Waldron

Editor

Upcoming nesting behaviour traits, such as the exact oviposition time or the time spent in the nest, have a direct impact on economically relevant aspects. Hens which stay for a long time inside the nest box, require more nest capacity which result in higher investments for the farmer. This is similar to flocks in which most of the layers have the need to lay their eggs in a short time frame during the day. For both of these nesting behaviour traits, published data have shown strain differences. While brown layers are more relaxed in terms of their oviposition time, almost 90% of a white layer flock lay their eggs within 3 hours during the morning. Additionally, a white layer on average occupies the nest 15 minutes longer than a brown layer. The estimated heritabilities for both traits are on a medium level of around h² = 0.25, and are therefore susceptible to genetically-linked changes. Lower heritabilities are estimated for indirect nesting behaviour traits such as the time interval between two consecutively laid eggs (h² = 0.09) or the total clutch size (h² = 0.25). Ranging behaviour traits also show heritabilities on a medium level. The published heritability for the frequency of passages as well as for the length of stay in the winter garden is h² = 0.24, however, their relationship to the most important selection trait ‘egg number’, is negative. The laying performance tested with the Funnel Nest Box (FNB) show differences to the recorded egg number of full sibs which have been tested in cages. Tabled genetic parameters showed low correlations for the egg number at peak production (rg = +0.2 to rg = +0.4) which could be explained by genotype x environment effects. Other traits like egg weight, early egg production and body weight show high correlations between both testing environments.

Due to the potentially undesirable effects of antibiotics as growth promoters in poultry production, researchers are looking for viable alternative to limit or replace their use. One such class of comparable alternative is natural source of herbs and medicinal plants. In the last decade, these alternatives have been increasingly used in broiler, layer and Japanese quail diets. Reports have variously claimed that medicinal plants, used as either the whole plant, their leaves or flowers, can enhance poultry performance. From the available literature, it can be concluded that thyme (Thymus vulgaris) belongs to such class of medicinal plant and may be an effective alternative to antibiotics in poultry production. In this review, its effects on different parameters of production performance in poultry are briefly discussed.

Agriculture in the 21st Century is facing new challenges and transformation according to five general trends: commercialisation, internationalisation, science and technology, environment and energy production. In this laboratory, a series of research, development and commercialisation of biogas and enzyme technologies reflect these trends. Anaerobic digestion is a microbial process that converts organic waste into biogas, containing 60-70% methane. A simple thermophilic anaerobic digestion (TAnD) system for poultry manure was developed from the lab to the farm. TAnD at 50 to 60°C produces biogas at high rates and, as a result, the process is efficient and the digester is a compact unit. A pilot plug-flow TAnD was first constructed and operated at NCSU research farm. Multiple benefits of the system were demonstrated. Supported by UNDP, a TAnD to process five tons of manure daily (from 50,000 hens) was constructed in China and has been operating for 20 years. Large scale digesters processing hundreds of tons of manure daily are increasingly popular in China and Europe. Biogas from large digesters can be a significant source of energy to generate electricity or to fuel transportation. Beyond energy production, the digester is a rich source of biomaterials. A feather-degrading bacterium was discovered and isolated from TAnD, and its keratinase enzyme and the gene encoding for the enzyme were subsequently isolated. Genetic manipulation for over-expression and up-scale fermentation have now made the industrial production of the enzyme possible. As a heat-stable protease, the keratinase was found to be useful in processing feather meal, in enhancing feed digestibility and was able to degrade prion proteins (implicated as the disease vector in bovine spongiform encephalopathy).

Poultry researchers and nutritionists are looking for viable alternative feed additives since conventional supplements have been criticised for their potential negative impact on the food chain. Among the currently available poultry feed additives, natural herbs and plants have been widely advocated due to their reported widespread beneficial effects. Garlic (Allium sativum) is one such potential feed supplement which has recently been reported as having a wide range of beneficial effects on the production performance and physiological biochemistry of broilers and laying hens. Notable beneficial effects have been seen on growth, feed efficiency, egg production and quality, as well as stimulation of immune system and lowering blood cholesterol levels in poultry birds. The results reported vary from author to author probably due to variations in the dose of the product fed, the duration of feeding and processing techniques employed.

Many cues for selection exist in poultry breeding, giving important insights into the future selection of elite progeny. Among these cues, the comb is an important reliable parameter for selection within variety or breed. The development of the comb is associated with hormone levels in the body which affect both productive and reproductive parameters. Comb affects the mating behaviour of birds and may be used as an indicator for selection by examining its impact on performance. Strong selection for increased comb size has been shown not to affect male mortality but is linked to increased female mortality. The production traits of layers have a positive correlation with comb size. The following paper provides a review of the comb as an important ornamental trait, including its morphology, development, use as a selection tool and the effect of comb size on productive and reproductive traits.

The feasibility of feeding insects on different types of waste materials and subsequently feeding insects to poultry is reviewed. Research in this area has demonstrated that a number of insect taxa including silkworms, locusts, fly larvae, crickets and grasshoppers can be safely fed to chickens without compromising the quality and palatability of the meat. Most studies on the topic have dealt with which species of insects can be fed to chickens; they did not investigate rearing insects commercially which requires knowledge of insect rearing, feeding and production methods. This review examines this issue in greater depth by reviewing current literature and through discussions with the poultry farmers in the states of New South Wales and Queensland, Australia. A survey of poultry farmers found an acceptance of feeding insect to poultry provided it could be done economically and indicated that insects could be reared and fed on a variety of organic waste materials which are available in adequate amounts in different regions. The technique of feeding insects to poultry will be beneficial in developing agriculture based recycling systems, reducing waste and potentially aid in reducing environmental pollution. Depending on the insect species and whether the diet of insects is fed to meat producing or egg laying birds it will likely need to be supplemented with either or both calcium and limiting amino acids to meet the chicken's dietary requirement. The safety and economic viability of breeding and rearing insects on organic wastes and feeding to poultry needs to be assessed. In order to be economically feasible, the overall cost of rearing and feeding insects to poultry needs to be lower than the cost of feeding conventional protein sources like grains and soybean meal. The technique of feeding insects to poultry needs to be able to be easily adopted and readily adaptable by the industry to a range of farming systems. Further research needs to investigate these issues in more detail both by establishing small experiments and developing production models which include insects reared ‘onsite’ in the poultry diet.

Published literature on the effect of carbohydrase enzymes (CE) on energy availability, nutrient digestibilities and growth performance of broilers fed corn-soybean meal-based diets is reviewed. Data from experiments involving CE preparations displaying single- to multiple-activities has shown improved metabolisable energy by 3% and digestibility of protein by 5%. Despite the observed variation in absolute values for individual amino acids, the improvement in amino acid digestibility appeared to be 27% of the undigested fraction. The positive effect on nutritive value are consistent with the improvements in body weight gain (0.8 to 10.4%; mean = 4.3%) and feed efficiency (1.3 to 9.3%; mean = 3.7%). Possible mechanisms contributing to these effects and the factors thought to explain the variability in responses has been discussed.

Among more than 750 known carotenoids, canthaxanthin (CX) has a special place as a carotenoid with proven antioxidant and other biologically-relevant functions. A substantial body of evidence indicates that CX possesses high antioxidant activity which has been shown in various in vitro model systems as well as in animal experiments in vivo. It seems likely that the highest protective effects of CX are seen under various stress conditions. This compound may be considered as an important element of the integrated antioxidant system of various tissues in the body, including chicken embryo development. A possibility of the recycling of vitamin E by carotenoids, including CX, is of interest for further investigation. Taken together, the data analysed in the paper clearly indicated that CX could provide benefits for animals, including in eggs and embryos as well as for chickens during early postnatal development. In particular, CX is well absorbed from the diet and effectively transferred to the egg yolk and developing embryo. It possesses high antioxidant activity and participates in building an effective antioxidant system of the body.

Two reviews are available in published literature relating to the effects of ascorbic acid on poultry performance. The first review was written by Pardue and Thaxton in 1986 who reviewed the role of ascorbic acid in alleviating the negative effect of heat stress in poultry birds. The second review was presented by Whitehead and Keller in 2003, who detailed the general effects of ascorbic acid in poultry birds, not taking into consideration ‘heat stress’. The first review is deficient in the literature published after 1986, while the second review does not describe the effect of ascorbic acid in heat stressed birds. The present review describes the past and present knowledge of ascorbic acid in alleviating heat stress in poultry birds with new aspects. Heat stress is associated with compromised performance and productivity through a decline in feed intake, nutrient utilisation, growth rate, egg production and quality, feed efficiency and immunity. Heat stress is also characterised by a reduced antioxidant status in birds, resulting in increased oxidative stress. Moreover, male fertility is decreased when birds are exposed to heat stress. Supplementation of 250 mg of ascorbic acid per kg of feed has been found to be optimum to improve feed intake, body weight gain, feed efficiency, egg production and quality, nutrient digestibility, immune response and antioxidant status in poultry birds. This work compiles past and present information about the role of ascorbic acid in heat-stressed poultry.

Chicken production scenarios, feedstuff resources, and experience of using alternative ingredients were reviewed with the aim of improving chicken production in Ethiopia. The common production systems used for chicken production in Ethiopia are traditional, extensive types. There is a high demand for protein foods, particularly those from poultry in this country. However, the performance of chickens in Ethiopia is poor and consequently the demand for chicken products is not met. This sector is characterised by insufficient levels of co-ordination, little or no specialisation or vertical-integration. Issues with feed are the main factors contributing to reduced chicken productivity, subsequently discouraging chicken producers. Moreover, the recent feed price increment is upsetting many plans for further development of poultry production in this country. Consequently, poultry populations and the per capita consumption of eggs and poultry meat in Ethiopia have been declining. Furthermore, the competition between food and feed is expected to further increase the feed price, forcing producers to look for alternative feeds and locally available feeds for their birds. Possibilities to improve the utilisation of by-products for poultry feed must be reviewed for poultry producers. It is concluded that headway options for alternative feed sources to improve the productivity of chickens in Ethiopia must be explored to alleviate some of the problems seen in this industry.

The impact of avian influenza (AI) on Thai indigenous chicken genetic resources following the outbreak of the disease in 2004 forms the main objective of this review. A survey was performed on 482 households from 27 villages in seven sub-districts. A total of 482 households representing the North, Northeast and central regions of Thailand were extensively interviewed. All villages had incidents of AI outbreak and chicken depopulation, according to government records. After the AI outbreak, most parental restocking of indigenous chickens in the Northeast and North was from local or home-grown areas, while restocking in the central region was from various external sources. The result found that approximately 45% of those interviewed decreased the number of chickens reared, 40% restocked chickens back to the original number, 15% increased the number of chickens reared, and a few stopped rearing altogether. Thai indigenous chicken strains are traditionally classified by feather colour: black, yellow, red, grey, striped, green, straw, bronze and white. A total of 679 mature and 387 young roosters were photographed and classified by feather colour, shank colour, and comb types. It was found that the AI outbreak had an impact on the genetic resources of Thai indigenous chickens. The percentage of the black-feathered strain, which is mainly found in the North and Northeast, is now in decline. The yellow-feathered strain, which is mainly found in the central region, has also noticeably decreased. On the other hand, mixed strains started to increase. Consequently, the original indigenous genetics tended to represent less and less of the total population, while mixed strains continually increased. This study revealed that the AI outbreak had an impact on genetic diversity of Thai indigenous chickens of Thailand.

Ducks are considered to play an important role in the transmission and maintenance of the Highly Pathogenic Avian Influenza (HPAI) virus. However, there is limited information on duck management practices in countries where HPAI is endemic. A cross-sectional questionnaire survey was conducted on 96 ‘stationary’ smallholder duck farms in Indonesia to describe the management of ducks and to identify practices that could potentially promote the risk of HPAI spread. The mean flock size was 29 ducks, ranging from 1 up to 150 birds. Both the sale and the consumption of eggs were the most important purposes of duck keeping, followed by the use of droppings for fertilizer and the production of meat ducks. About 77% of duck owners allowed their ducks to scavenge. Important hazards for interspecies HPAI virus transmission related to scavenging were identified: 1) intermingling between ducks and chickens on duck farms (48%); 2) frequent contact with neighbours’ chickens (44%); 3) visits to the same paddies by duck flocks from other farms (88%); 4) in the paddies, contact between duck flock and other ducks, chickens, people and wild birds as reported by 88%, 30%, 80% and 77% of duck owners respectively; 5) the keeping of singing birds by 17% of farmers; 6) predators such as the small Asian mongoose (Herpestes javanicus) (25%) and feral cats (20%) visiting the duck farms (these species are susceptible to HPAI infection and might play a role in the spread of the HPAI virus). Many duck owners associated deaths of their birds with the use of pesticides in the rice paddies, and appeared to be more concerned about pesticide toxicity, problems that inhibit scavenging ability and external parasites than about HPAI, which in general was not considered to be of high importance. Hence HPAI vaccination or preventive culling of ducks during disease outbreaks was not conducted on the study farms.

Data from a three-year panel (2006–2008) obtained from selected respondents, was used to investigate the impact of the avian influenza (AI) outbreak on the chicken markets in Benin. The trends in sales volume and profit were used as proxy for performance. The Generalized Method of Moments (GMM) regression model was used to examine the factors affecting profit. In general, the AI outbreak adversely affected the performance of the markets during the imposition of restrictions on poultry trade. When AI broke out in Benin and poultry trade restrictions were imposed, the volume of chickens sold per market day per seller declined by 69%. Overall, the AI outbreak did not have an adverse effect on the profit made by the poultry producer/sellers and middlemen. The regression results suggested that the chicken market is more favourable in terms of profit margin for women, literates, young people, middlemen and sellers in Kolokonde regional market. The municipal authority's levy has a negative effect on profitability, while the undersupply of chickens and average volume of sales per market day and provision of market shelters have positive effects. The level of state authority's levy, provision of market infrastructure, women and youth empowerment programmes and behaviour of poultry suppliers have implications for policy measures in the poultry sector.

WPSA has played a pivotal role over the past 100 years in facilitating the development of the global poultry industry through the organization of branches in member countries and forums to identify and discuss issues, problems and their solution, as well as structures to disseminate that information. In this manner, WPSA has, since 1956, contributed significantly to the development of the Australian poultry industry. The Australian poultry industry has benefitted greatly over the years as a result of a well-supported and high quality national poultry research programme, facilitated through close cooperation between the poultry industry itself, national and state governments, and the country's research and education institutions.

In response to the major projected increase in poultry meat and egg production and consumption in developing countries, WPSA has focussed increasing attention on facilitating efficient, sustainable and socially equitable poultry production in these countries. Associated with this, WPSA and WVPA are working towards a closer degree of cooperation and collaboration.

Waterfowl production has been on an upward trend and has become increasingly important around the world over time. The production of ducks worldwide in 2010 was 6-fold greater that of 1961, and that of geese was 9.8-fold over the same period. The progress in waterfowl production represents not only an increase in the quantity of the product, but also in quality. Waterfowl performance progress, genetics and breeding, reproduction, nutrition, management and housing, and product quality and utilisation are discussed in this article, alongside a review of the history of the Waterfowl Working Group (WWG) which was established in 1969 as Working Group 8 under the European Federation (EF). After moving to the Asian Pacific Federation (APF) in 2011, it became Working Group 2.

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.