At the time of writing (and the Journal is always prepared several months before the print copy reaches our readers) I am sat in the cold wet winter of New Zealand. As such I am keeping warm and dry inside with the heating on full. You may think this is just some of my ramblings – $ but it does have a point – one of our papers this issue is a very interesting comparison of welfare between the different methods of poultry husbandry. As such, from this and other behavioural studies, it seems that people and chickens have certain aspects in common – we both prefer the indoors when its nasty or dangerous outside.

This issue covers areas including fertility, nutrition and alternative feed materials, specialist ingredients for growth and disease prevention. The WPSJ always strives for variety in the papers it publishes – hence if any members have a novel project ongoing, please consider us for publishing a review. In addition, some of you may have noticed that we are now using FirstView to get papers out online as soon as the editing has been completed – this will help get papers out earlier and as they are finished – no more waiting for the next print issue. These papers will still be assigned and cited for the issue they are ascribed to, and of course the print issue, for those members that need it, will still be posted out in the same way as before. In addition, after board meetings and dicussions with the FAO, it has been decided that INFPD papers, unless they have global appeal, shall be sent for FAO publication. Thanks to Drs Fallou Gueye and Olaf Thieme for their help in this. For anyone with local INFPD papers – please contact Fallou directly at [email protected].

I have been privileged to be invited to attend the PSA meeting in Kentucky in July and I am greatly looking forward to seeing many US based authors, editors, colleagues and friends during the conference. Many thanks to the organisers and those at WPSA US branch for arranging this. We are currently gearing up for the next board meeting – to be held at the Prague conference at the end of August. Looking forward to seeing many reviewers and authors there! Of course, this will already have happened by the time the September issue goes to print - such is the timescales of print publishing.

Dr Lucy Waldron

Editor

The design and management of different housing systems affect poultry welfare. In order to compare wellbeing in different systems, two main indicators of poor welfare have been used in this paper: contact dermatitis for meat birds and mortality for laying hens. The former is important since broilers may suffer from it for much of the later part of their short lives; the latter because it is generally preceded by suffering due to morbidity. Other welfare indicators are also important, of course, and some of them have been considered alongside these two. Indoor systems, especially laying cages, provide the safest welfare protection but extensive systems, e.g. free-range, provide more freedom and allow the widest behavioural repertoire. However, free-range systems are generally the most difficult to manage and pose the greatest welfare risks, which can sometimes be serious - even causing death. A possible superior safer approach is suggested.

Keel bone damage (KBD) is a critical issue facing the contemporary laying hen industry due to the likely pain leading to compromised welfare and reduced productivity. Recent reports suggest that KBD, while highly variable and likely dependent on a host of factors, extends to all housing systems (including traditional battery cages, furnished cages and non-cage systems), genetic lines, and management styles. Despite the extent of the problem, the research community remains uncertain as to the causes and influencing factors of KBD. To combat these issues, the current review was produced following discussions from the 1st International Keel Bone Damage Workshop held in Switzerland in April 2014. This exercise sought to assess current knowledge, foster novel collaborations, propose unique methodologies and highlight the key areas where innovative research is needed. The following paper is based on the content of those discussions and presents nine recommendations for future research efforts.

Chlamydia (C.) psittaci, formerly known as Chlamydophila psittaci infections cause important economical losses to the poultry industry and are a danger to public health. The economic and zoonotic impact of C. psittaci infections in the Western poultry industry is well documented. Less is known on its occurrence in Asia. In the following review we address C. psittaci infections in Chinese poultry in view of China supplying 40.8% of global egg production and 14.2, 69.3 and 91.1% of global chicken, duck and goose meat, respectively. The current paper compiles English and Chinese scientific literature on C. psittaci infections in Chinese poultry. The paper is focusing on seroprevalence, culture, direct antigen detection, molecular characterisation, observed symptoms, Chinese traditional medicine and psittacosis case reports. A review on the epidemiology of chlamydiosis in Chinese poultry clearly illustrates the widespread presence of virulent C. psittaci strains in chickens, ducks and geese across China. In Western countries, C. psittaci infections in poultry are principally treated with antibiotics. In China, however, herbal medicine is often used in conjunction with antibiotic treatment or as prophylaxis. The applied production and marketing systems facilitate zoonotic transfer. Chinese occupationally acquired psittacosis cases include reports on infections contracted from ducks, pigeons, chickens and peacocks.

Nutrients such as minerals and vitamin D have clear roles in skeletal metabolism. Boron (B) has been examined as a possible essential nutrient in the metabolism and utilisation of several micro nutrients and hence could have an influence on bone mineral density and eggshell quality. However, there have been few direct studies to examine the dietary response to B in chicken and layer hen models, although there is evidence that both compositional and functional properties of bone are affected by dietary boron status in other model animals and humans. Bone integrity, skeletal problems in chickens and eggshell quality in laying hens are important economic, welfare and health issues for the poultry industry. Therefore, better understanding of certain role of B on mineral availability in chickens and layer hens is important to enhance productivity and improve animal welfare. The following review examines the published data relating to these aspects of B in poultry feed.

Synthetic methionine use is currently limited to 1 kg and 1.5 kg per metric tonne (2, 2, and 3 lbs per short ton) of feed for organic laying hens, broilers, and turkeys and other poultry, respectively, in the United States of America. All other synthetic amino acids (AA) have been banned from use in organic poultry diets in this country. It is challenging to provide sufficient methionine (Met) to maintain bird growth and productive performance up to current industry standards given the recent restrictions that have been placed on synthetic Met. Without synthetic AA, Met requirements can alternatively be obtained for organic poultry by dramatically increasing dietary crude protein (CP) e.g. via additional inclusion of expeller-pressed soybean meal to the diets. However, this strategy leads to both major increases in feed costs and environmental concerns due to increasing nitrogen excretion, with concurrent rises in ammonia emissions, and corresponding welfare issues due to ammonia and litter quality. This review aims to examine feed ingredients that may contribute to a solution to this issue. Otherwise, further negative impacts may soon be felt from the current limitation on synthetic Met or a potential ban on its entire use in the future.

Smallholder farmers in Africa and other developing countries raise village chickens under low input production systems characterised by minimal management and veterinary interventions. However, village chickens have a major contribution to village communities as a source of protein, income and cultural needs. The village chickens are described as nondescript birds that have not been developed as a breed and with uncharacterised genetic attributes. Local chickens are found in the most marginalised farming systems, to which they have adapted and survived the harsh production and environmental conditions. Such survival and adaptive attributes need to be characterised, conserved, and utilised. Several studies on Southern African local chickens have revealed high genetic variation within and among the village chicken populations and indicated that village chickens contribute diversity that is unique and different from that of commercial and specialised chicken populations. The availability of whole genome single nucleotide polymorphism (SNP) data facilitates the use of powerful statistical methods for in depth investigations into the evolutionary history and population demographics of village chickens. Linkage disequilibrium (LD), as a function of effective population size, has been used to estimate rate and level of inbreeding as well as selection pressures in the absence of pedigree information. The extent and distribution of LD in the genome has been exploited to shed light on the origin and domestication of animals and facilitate an understanding of breeds’ relatedness. The Illumina iSelect chicken 60K SNP chip has over 54 000 SNPs that have found application in population and quantitative genetics studies and has revealed demographic history, effective population size and level of genetic erosion in commercial and traditional/village chicken populations. The recent launching of the 600 K Affymetrix® Axiom® HD genotyping array for chickens and the ever decreasing cost of sequencing will see improved estimation of LD and the associated population parameters.

Although fertility rates are dependent on both sexes, this characteristic is most often associated with males. For example, the practice of spiking, in which males with undesirable characteristics are replaced with younger males, is often used to improve fertility rates. Dietary restrictions may offset genetic shortcomings to some extent, but nutritional deficiencies due to dietary restrictions may themselves reduce the efficiency of breeding systems. Thus, the challenge is to maintain rooster fertility even when they are receiving diets that meet the nutritional requirements for females. Subjective visual selection is often used for diagnosis of roosters as being unfit for reproduction, with those deemed as overweight or underweight, or those with too small a comb and/or too slightly pigmented, among other phenotypic parameters, being removed. Diagnosis of infertility may only be confirmed after sperm quality evaluation, with reliance on visual diagnosis often resulting in discarding of roosters suitable for reproduction but with unfavourable visual characters. This review aims to characterise reproductive management of roosters in Brazil, highlight aspects of their physiological and sperm quality parameters, and explore nutritional strategies that might contribute to extending their reproductive life.

The poultry industry is affected by economically important problems such as Newcastle disease (ND). Newcastle disease virus (NDV) belongs to the Paramyxoviridae family and manifests as different strains; lentogenic, mesogenic and velogenic. ND affects the quality of eggs and impairs growth performance of birds. Various efforts have been made to control economic losses due to this disease, including using live and killed vaccines, which do not confer 100% immunity in all cases. Due to mutations within viral strains, NDV can become resistant and difficult to control, and there is a need to search for alternative measures. Medicinal plants are considered as a complementary means to control this virus, especially in developing countries, because they have been implicated in treatments for a variety of infectious and non-infectious diseases. Alkaloids, flavonoids, saponins and tannins found in plants have been regarded as novel antiviral agents. The following paper encompasses the studies related to plants having in vitro antiviral activity against ND such as Momordica balamina, Adansonia digitata, Artemisia annua, Azadirachta indica, Psidium guajava, Moringa oleifera and plants having good in vivo antiviral activity such as Aloe secundiflora, Cucumis metuliferus and Anthocleista nobilis as well. It discusses plants with the potential to improve the immunity of infected birds, such as Mangrove halophytes, Nigella sativa, Polysavone, Melissa officinalis, Momordica cochinchinensis, Echinacea purpurea, Withania somnifera and Aspargus Racemosus.

The aim of this review paper is to show the most important bioactive compounds of garlic (Allium sativum L.), modes of action of garlic powder and its effects on broiler chicken productive performance. Allicin is thought to be the principal bioactive compound present in aqueous garlic extract or raw garlic homogenate. When garlic is chopped or crushed, the allinase enzyme present in garlic is activated and acts on alliin to produce allicin. Other important sulphur containing compounds present in garlic are allyl methyl thiosulphonate, 1-propenyl allyl thiosulphonate and γ-L-glutamyl-S-alkyl-L-cysteine. These active compounds are thought to influence feed consumption, feed utilisation, body weight, blood lipid profiles and cholesterol levels in chickens. Biological responses to these bioactive compounds have been attributed to a reduction in risk factors for cardiovascular diseases and cancer, stimulation of immune function, enhanced detoxification of foreign compound, hepatoprotection, antimicrobial, antifungal, anti-inflammatory and antioxidant effects.

Intensive poultry production is heavily reliant on electricity for maintaining shed environments as well as in the supply of feed, lighting, the shed environment and water. During the last three decades, the demand and supply gap for electricity has plagued Pakistan. The energy crisis became even worse from 2006-07, with 18 hours rotational load shedding being implemented. During the last decade, there has been a major increase in environmentally controlled poultry farms in Pakistan which require continuous electricity supply to operate their automatic feeding, drinking and environmental control systems. Broiler farmers have opted for diesel generators to meet their electricity needs, which has subsequently increased total cost of production. Therefore, sustainable and economical energy solutions are required for Pakistani broiler farmers to be competitive in local and international markets. In this paper, the potential for solar energy is analysed, the poultry industry's energy needs are quantified and the use of PV-diesel hybrid power systems in environmentally controlled broiler houses is examined.

There are several species of snail with varying nutrient profile. The protein content of snail meal (53-83%) is comparable to or higher than fish meal. Apart from lower methionine, the essential amino acids composition of snail protein is similar to fish meal and better than soybean meal. The fat of snail meal is high in polyunsaturated fatty acids and has a good supply of essential fatty acids (linoleic, linolenic and arachidonic acids) and minerals. These qualities make the meal a suitable substitute for more expensive, conventional protein feedstuffs. The variability in nutritional content, potential presence of anti-nutritional factors (cyanide, tannins and saponins) and the seasonal availability of snails (mainly during the moist season) are major factors limiting the use of snail meal in poultry diets on a commercial scale. However, heat processed snail meal could be effectively utilised for practical on-farm feed applications to reduce cost and provide an environmentally friendly method of controlling snails, especially where they are major agricultural pests. In suitable regions, snails could be intensively bred to ensure the availability of the meal in commercial quantities for poultry feeding. Heat processed snail meal is recommended at 10% in the diet of meat and egg-type chickens but raw snail meal is not. The composition of snail meal (nutritional and anti-nutritional properties), recommendations in diets for domestic chickens, results of some feeding experiments and major constraints to its efficient utilisation are discussed in the following paper.

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.