Increased pressure on the poultry industry by animal-rights organisations and environmentally-conscious consumers has led to the rising popularity of cage-free housing system for hens. One of the main dangers of cage-free housing systems is the possibility for laying hens to damage their keels. Keel bone fracture incidence rate ranges up to 85%, and can lead to extensive pain in any bird, and potentially be the cause of the death for a hen in a cage-free environment. It was reported that kneel bone damage observed in flocks housed in non-cage systems was 30 to 95% while in furnished cages it was 15 to 55%. The purpose of this review is to compare the prevalence of the problem found in the three main housing systems (conventional, enriched cage, and cage-free), discuss if such damage could affect the behaviour and production of laying hens, and provide potential solutions for reducing the prevalence of keel bone damage. Keel fractures can negatively affect a hen in its day-to-day life by causing pain and restricting its movements. The prevalence of keel bone damage varies considerably among the studies due to differences in the system design, genetic line, age and method for determining the keel damage, which makes difficult to compare the systems. The genetic selection, adequate nutrition and modifications in the house design have shown to be useful tools in reducing keel bone damage in laying hens.

The World’s Poultry Science Journal is indebted to Prof J.A. Castello, Prof D.K. Flock, Dr M. Tixier-Boichard, Dr S. Cherepanov and Dr Jiangxia Zheng for the translations of these summaries.

Global poultry production has increased rapidly over the last 50 years and is now the most-consumed meat species in the world. The consumption of poultry in Poland accounts for almost 40% of the total meat consumption and averages 30 kg per person. Being the most flourishing sector of agriculture, poultry production faces many challenges from increasing competition (high quality products and lower prices for consumers). The profitability of poultry breeding and rearing is determined by the production of healthy and well-developed chicks, and the value of hatching eggs is closely linked to genetic line, flock age, layer housing conditions and parent flock nutrition, as well as incubation and pre- and post-hatching management. The qualitative assessment of newly hatched chicks must be based on clear and objective methods regarding health status of the flock and performance of the birds. It is essential that modern poultry production pays particular attention to these factors to achieve a high percentage of hatchability and the production of chicks which fully express their genetic potential under intensive production systems.

Chicken housing systems have been an interesting subject of research for many years and remains a topic of debate. The information detailed in the literature provides opposing views on recommended housing systems (indoor or outdoor) for chickens, and thus, producers are searching for more precise information in terms of animal welfare, productive performance, chicken behaviour and meat quality. Approximately 80% of customers worldwide prefer chicken products with perceived higher quality derived from free-range (organic) systems with increased welfare standards. Based on published literature, the majority (approximately 70%) of intensive production systems that are currently used do not usually support the natural behavioural needs of poultry. However, mortality rate of broilers can reach more than 10% in outdoor production systems due to cannibalism. Suitable housing systems that focus on the animals’ well-being translate into better behavioural activities and higher productive performance. The present review provides the critical information detailed in the existing literature on different housing systems and their effect on chicken behaviour and meat quality. It can be concluded that the housing system, as a non-genetic factor, directly affects the welfare of the birds and can impact their behaviour and certain meat quality traits. Thus, the free-range production system might be considered favourable alternative housing system.

Supplementing flavonoids in poultry diets has shown the potential to progress the nutritional, sensorial and microbiological quality of poultry meat and eggs. In the last decade, several studies have determined the benefits of flavonoids for inhibition of lipid oxidation and microbial growth, check any pH-dependent deterioration and improve the colour stability of meat and related products. Flavonoids are typically absorbed in the ileum where pH is between 5-6.8. The various flavonoids vary in effective dose levels in poultry, but are typically included in levels ranging from 0.05-0.2%. Furthermore, flavonoid supplementation in the chicken diet has been reported to positively alter the fatty acid profile of meat and eggs by reducing the cholesterol and triglyceride content. Meat colour, in terms of lightness, can be improved by up to 5%. The aim of this review is to evaluate the use of various plant flavonoids as a substitute for synthetic feed additives in the poultry feed industry to satisfy consumer demands in terms of quality and safety of animal products. The results have stimulated interest in more research on the various flavonoid classes to determine the most effective compounds and their optimal doses for both broilers and laying hens.

Dietary lutein has received considerable attention in relation to human health because of its preventative effects on various eye diseases. Eggs are considered a good source due to good accumulation and relatively high concentrations of lutein. Therefore, many studies have been conducted to produce lutein-enriched eggs by various dietary regimens. Previous studies reported that purified lutein supplements, at the inclusion levels of up to 1,000 mg/kg, increased concentrations by up to10-fold in eggs. However, a linear increase in lutein concentrations in eggs failed to show further increases at very high inclusion of lutein supplements. The use of feed ingredients high in lutein such as corn co-products, alfalfa meal, marigold flower extracts, algae-derived products, and even food ingredients have successfully increased lutein concentrations in eggs. For instance, inclusion of 20% corn distillers dried grains with solubles (DDGS), 7% corn gluten meal, 2% marigold flower extracts, or 2% chlorella products in layer diets showed more than two-fold increase in lutein concentrations in eggs. However, the efficacy of those ingredients for lutein retention in eggs was highly variable and depended on inclusion levels in diets and feeding periods. Finally, non-dietary factors such as management systems, environmental stress, disease, age, and breed may affect the lutein concentrations in eggs; however, limited information is available in this regard.

Supplementation of poultry diets with medicinal plants containing bioactive molecules have shown promising results in promoting growth performance, enhancing feed efficiency, and improving carcass traits and meat quality. There are many studies using herbal plants and their derivatives involving liquorice (Glycyrrhiza glabra), while studies using only liquorice are very limited. Liquorice contains bioactive components such as glycyrrhizin and flavonoids, and has been linked to many pharmacological effects like immunomodulatory, anti-oxidant, antiviral and anti-inflammatory activity. Supplementation of liquorice in poultry diets had beneficial impacts on growth and performance by improving organ development. In addition, there are appetite and digestion stimulating factors in liquorice. Dietary liquorice supplementation at level of 2.5 g/kg showed the best results in broiler chicken, and demonstrated it can be safely used in poultry diets. Addition of liquorice in diets up to 0.5% inclusion before sexual maturity enhanced performance of laying hens. Furthermore, broilers receiving drinking water containing 450 mg/l liquorice under heat stress significantly improved feed conversion and economic efficiency. Abdominal fat in broiler chickens was decreased when liquorice was included at 2 g/kg in feed or 0.3 g/l in drinking water. Broiler chickens with access to drinking water containing 450 mg/l of liquorice increased the dressing percentage, with or without giblets. Carcass organoleptics were improved in birds receiving drinking water with liquorice at levels of either 1, 2 and 4 mg/ kg body weight. This review describes the chemical composition, health benefits and beneficial applications of the liquorice herb and its effect on growth and productive performance, carcasses and meat quality, which will be useful for researchers, physiologists, nutritionists, veterinarians, scientists, pharmacists, pharmaceutical industries, and poultry breeders.

The World’s Poultry Science Journal is indebted to Prof J.A. Castello, Prof D.K. Flock, Dr M. Tixier-Boichard, Dr S. Cherepanov and Dr Jiangxia Zheng for the translations of these summaries.

The World’s Poultry Science Journal is indebted to Prof J.A. Castello, Prof D.K. Flock, Dr M. Tixier-Boichard, Dr S. Cherepanov and Dr Jiangxia Zheng for the translations of these summaries.

Chlorella (vulgaris spp.; CLV) is a genus of unicellular freshwater microalgae that are fit for human consumption and are used as additives with high nutritional value in feed for agriculturally important animals. Chlorella spp. are characterised by their simple cultivation, high productivity and levels of protein and other nutrients. Investigations have shown that the growth performance of broilers can be positively affected by the addition of very low amounts of CLV biomass (0.5-1.0% of the diet) to feed. The effect of CLV on growth and development is considered to stem from its high protein content (60.6%) and nutritional value. Results have shown enhanced body weight gain (2.7%), better feed conversion ratio (lowered by 2.8%), meat colour and breast muscle weight (20.1%) in CLV-supplemented chicks compared to control birds (control breast weight 19.1%). Additionally, a significant decrease in drip loss (2.26%) from breast muscle was observed with CLV supplementation and levels of blood total protein, albumin, and high-density lipoprotein (HDL) cholesterol significantly increased (P<0.05), while the levels of liver enzymes indicative of oxidative damage (alanine aminotransferase, ALT) decreased by 23.2%, indicating better liver function. In terms of immunity, blood lymphocytes were increased in broilers fed a diet supplemented with liquid CLV (17.9 x 103/µl) compared with birds supplemented with dry CLV (13.5 x 103/µl). Additionally, the levels of IgA, IgG, and IgM were elevated by 29.7%, 69.1%, and 32.3%, respectively, in broilers that consumed feed containing CLV. Similarly, the intestinal diversity and abundance of Lactobacillus spp. were significantly increased (9.9 ± 1.88 and 8.99 log10 CFU/g, respectively) by dietary supplementation with liquid CLV compared to that in non-treated chicks (8.7 ± 1.22 and 8.51 log10 CFU/g, respectively). Energy digestibility was increased significantly by 1.29% in CLV-treated chicks compared to the control chicks. This review highlights the findings associated with the utilisation of CLV biomass as a feed supplement and its effect on broiler growth and health.

Methionine: comparing methionine hydroxyl analogues for broilers, with focus on different thermal environments RETRACTION

F.S. DALÓLIO, V.R.S.M. BARROS, L.F.T. ALBINO, P.H.R.F. CAMPOS, J.N. SILVA and S.R.F. PINHEIRO

DOI: https://doi.org/10.1017/S0043933919000230

Published online by Cambridge University Press: 05 April 2019

After publication of the paper entitled ‘Methionine: comparing methionine hydroxyl analogues for broilers, with focus on different thermal environments’ (Dalólio et al., 2019), the journal received a complaint alleging wrong citations and statements, and misleading conclusions. Specifically, the bioequivalence between methionine sources was deemed erroneous. Following COPE (Committee on Publication Ethics) guidelines and due diligence, the editor and publisher investigated this claim with the reviewers, the Board and the authors in detail. The corresponding author acknowledged and accepted the errors, and all authors have been informed of the retraction of the paper. Broadly, the problems with the paper are mainly concerned with misrepresentation of the technical information from the papers they used in their review of commercial methionine products.

The World’s Poultry Science Journal is indebted to Prof J.A. Castello, Prof D.K. Flock, Dr M. Tixier-Boichard, Dr S. Cherepanov and Dr Jiangxia Zheng for the translations of these summaries.

Henk Hupkes

June 6, 1947 - November 25, 2018

On Sunday November 25, 2018 the Dutch branch of the WPSA lost a charismatic member Henk Hupkes. Henk started his poultry career at Meyn Food Processing Technology B.V. in 1982: his graduation in Mechanical Engineering from the Technical University in Delft provided a good basis for his diverse tasks. Henk provided an indispensable bridge between poultry processing equipment manufacturers and the scientific world. In 1982 he became a member of WPSA NL and was a member of the regional Board from 1986 to 1992. He was member of the organising committee of the successful WPC held in 1992 in Amsterdam, after which he became member and secretary of the Board of the Foundation for Promoting Poultry Science until his death in November 2018. From 1982 to 2010 he attended about all WPCs and EPCs, as well as the symposia of Working Group 5 (poultry meat). In all cases his presence was undeniable due to his eagerness to learn, his friendly and optimistic attitude, and his sense of humour. Since 2015 Henk suffered from cancer, a battle he couldn’t win. He finally lost the battle at the age of 71. Henk is greatly missed by his loved ones and his many friends inside and outside the WPSA. He is remembered with respect, warmth and gratitude.

Jim McNab

April 5, 1940 – January 1, 2019

It is with great sadness that I have to announce the death of Dr Jim McNab, who died suddenly on January 1st. He was born in Comrie, Perthshire to Mary and Donald, in April 1940, and was much loved by his parents and his sister Mary.

Jim excelled in school, at Morrison’s Academy in Crieff. Outside studies he played for the school’s 1st rugby team and enjoyed playing the clarinet. He was also an ‘extra’ in the 1953 film ‘Johnny on the Run’.

From 1958 to 1965, Jim attended the University of Edinburgh with great enthusiasm and enjoyment. According to his good friend Dennis, academic issues were never a problem. After graduating with an Honours Degree in Chemistry he moved on to do his PhD in 1962, adopting three ‘Objectives’, the same ones most Graduate students pursued in the 1960s, namely a PhD in three years, a post-doctoral appointment in North America and finding the love of one’s life. He achieved the last of these when he met Carol during the first month of his PhD. He duly graduated in 1965 and set out for Boulder, Colorado, returning briefly for his marriage with Carol in October 1966. After a year in Colorado, they returned home and Jim spent a year back at Edinburgh University before he joined the Nutrition Department at the Poultry Research Centre (PRC) in Edinburgh in October 1968. His research covered many aspects of poultry nutrition, including the digestion of carbohydrate and protein and developing methods for feedstuffs evaluation. He studied feed quality enhancement and assessments of non-traditional feeds.

In 1993, Jim became the head of the large Department of Nutritional and Environmental Studies at Roslin Institute, the successor to PRC. The work of his department included behaviour, welfare and other environmental topics, as well as nutrition. He gave good leadership to this widely-based department and battled hard at senior staff meetings at the Institute where the essentially applied nature of his department’s work was regarded somewhat less favourably than some of the seemingly more exotic sciences carried out in others.

Owing to increasing pressure on government research funding, the idea of expanding commercial income from aspects of Jim’s research was proposed, including his methods for feedstuff evaluation assays. In 1997, Roslin Nutrition, a spin-out company from Roslin Institute, was born. Jim and Doug Currie were charged with managing the company, which in 2002 became a completely independent research company, which is still thriving today.

Jim was a well-known and popular figure in the poultry nutrition world and a regular speaker at industry and scientific conferences. His other activities at work included responsibility for many national and some international projects, supervising numerous PhD students, co-editing British Poultry Science for 10 years and, for a shorter period, editing World’s Poultry Science Journal. He was very active in the UK branch, organising symposia and conferences. Jim retired from the Roslin Institute in 2001 and from Roslin Nutrition in 2005.

Outside work, Jim enjoyed playing rugby, squash and bridge. He was a keen vegetable gardener and latterly an enthusiastic cook. He was a proud and loving father to his two sons, Donald and Scott and he adored his four grandchildren

When his wife Carol was asked for her thoughts she said: Jim is remembered as having a great sense of humour: being reliable, generous, loving; positive, honest and forthright; a good man, a great dad; an intellectual, wise, clever man; a kind patient and a wonderful person.

On a personal note, Jim was a mentor during my PhD, training me in various ME measurements and becoming a good friend, as well as being a previous editor of WPSJ. He is survived by his wife Carol and his children and grandchildren. I would like to thank Carol for her great help with preparing his obituary. Our thoughts are with the family at this difficult time.

Dr Lucy Waldron