This paper describes a case example where initiatives from private assurance schemes, scientists, charities, government and egg companies have improved the welfare of UK cage-free laying hens. The RSPCA and Soil Association farm assurance schemes introduced formal welfare outcome assessment into their annual audits of laying-hen farms in 2011. Feather loss was assessed on 50 birds from each flock on a three-point scale for two body regions: Head and Neck (HN) and Back and Vent (BV). In support of the observations, assessors were trained in feedback techniques designed to encourage change in farmer behaviour to improve welfare. In addition, during Year 2 farmers were asked about changes they had made, and intended to make on their farms. During 2011-2013 there were also wider industry initiatives to improve feather cover. Data were analysed from 830 and 743 farms in Year 1 and Year 2, respectively. From Year 1 to Year 2 there was a significant reduction in the prevalence of feather loss from 31.8% (9.6% severe) to 20.8% (6% severe) for the HN region, and from 33.1% (12.6% severe) to 22.7% (8.3% severe) for BV. Fifty-nine percent of 662 farmers reported they had made changes on their farms during Year 1 to improve bird welfare. For such a substantial industry change, attributing causation to specific initiatives is difficult; however, this is the first study to demonstrate the value to animal welfare of certification schemes monitoring the effectiveness of their own and other industry-led interventions to guide future policy.

The poultry red mite (PRM) is an obligatory haematophagous pest that causes substantial economic losses in poultry worldwide. The PRM does not live on the host but in the bird's environment and must find its host remotely. Hence, manipulating chicken odours is of interest. Several crude plant-originating volatile organic compounds (VOCs) have already been shown as repellent to Dermanyssus gallinae. We aimed to test whether these VOCs can interfere with PRM host-seeking behaviour by their oral administration to the poultry. The objectives were to determine (1) if hen odours are modified by supplemented feed ingestion and (2) if such treatment makes hens less attractive to the PRM. Chemical characterization by gas chromatography–mass spectrometry of the hen odour was conducted before and after the hens ingested the supplemented feed. The chromatograms obtained show that hen odour was substantially modified after the hens consumed it. Among the molecules recurrently detected from the supplemented hens, 26% were nearly absent in the unsupplemented hens. Behavioural choice tests to compare the effect of the modified and unmodified-host odours on the PRM show that some of the plant-originating emitted VOCs and the modified whole-hen odours were repellent to the PRM.

In the past, trace minerals have been inadequately considered by poultry nutritionists, as demonstrated by the scarce availability of literature. The practice of using high safety margins between requirements and dietary concentrations and the relative low cost of these essential minerals are possible reasons for this. Environmental considerations and regulations limiting trace mineral supply and improvements in analytical methods to detect putative contaminants in mineral sources have led to a need to a re-examination of trace mineral requirements. In addition, new knowledge regarding trace mineral roles in bone metabolism, anti-oxidant status, homeostatic regulation, product quality, immunology and the development of novel trace mineral sources have favoured, for the past 15 years, interests in optimising trace mineral nutrition considering other parameters than solely the bird performance. This review analyses the role of essential trace minerals (mainly Zn, Cu, Fe, Mn, I, Se) in broiler and laying hen nutrition. This work aims to highlight the evaluation of trace mineral requirement, the bioavailability of trace mineral sources, especially in regards with phytate antagonism, and the main functions of trace minerals in egg, eggshell and meat quality. The impact of trace minerals on the environment (toxicity to plants and microorganisms) is considered and nutritional means to reduce the risk of environmental contamination will be explored. Finally, the possibilities of poultry product's enrichment in some trace minerals for the benefit of human health will be explored.

Decontamination of egg shells is required to improve the microbiological safety of the fresh hen eggs used for human consumption or for hatching. Conventional chemical decontamination methods involving quaternary ammonium disinfectant, sodium hydroxide, phenol, hydrogen peroxide or formaldehyde, leave residues on egg shells that may damage the cuticle layer. Therefore new techniques of egg shells decontamination, such as ultraviolet (UV) radiation, have been developed. This review aims to evaluate the data from available literature and to provide a general review of UV light treatment application for egg shell decontamination. Data shows that UV treatment was effective for the inactivation of the bacterial population present on clean egg shells and recently contaminated shells. Combined treatments such as UV light with ozone or hydrogen peroxide (H2O2) improved the inactivation of microorganisms. Recent advances in science and engineering indicate that treatment with UV light has a competitive advantage in comparison with traditional egg shell sanitation treatments for decontamination.

The public wants assurances that animals used for food are raised humanely. Conventional cages for egg laying hens do not meet hen's behavioural needs, but cages have potential advantages such as improved liveability and respiratory health because of less aerial ammonia and dust as compared to non-cage systems. Providing amenities to cages might be a compromise that allows hens to reap some of the advantages of conventional cages and also better meet their behavioural needs. This review focuses on the perch as a furnishing and how its design and addition to the cage can affect welfare and production efficiencies of egg laying strains of chickens. Hens should have access to perches because of their high motivation and preference for perching. At night, hens like to perch at the same time which requires a straight perch space of 12 and 15 cm for White Leghorn and brown hybrids, respectively. Besides meeting a behavioural need, perches in cages improve bone strength, but the improvement is not great enough to prevent adult keel fractures and deformities. Perch access improves feather quality for the back but not for other feather tract areas. Foot pad, toe, and nail health are often improved with perch access in cages of smaller group sizes. With the exception of dirty and cracked eggs, perches installed in cages do not deleteriously affect hen performance. Commercial perches are available in different shapes (e.g., round, circular, or mushroom) and compositions (e.g., wood, plastic, or metal). There is no perfect perch relative to its material composition or shape. Wooden perches offer a rougher texture but harbour mites in crevices. Future research should concentrate on perch redesign that avoids slippery surfaces allowing hen's feet to better grip the perch, prevents keel fractures, is easily cleaned, and does not harbour parasites or pathogens.

A meta-analysis integrating results of 40 selenium (Se) supplementation experiments that originated from 35 different controlled randomized trials was carried out in an attempt to identify significant factors that affect tissue Se accumulation in chicken. Examined factors included: Se source (12 different sources examined), type of chicken (laying hens or broilers), age of birds at the beginning of supplementation, duration of supplementation, year during which the study was conducted, sex of birds, number of chickens per treatment, method of analysis, tissue type, concentration of Se determined and Se added to feed. A correlation analysis was also carried out between tissue Se concentration and glutathione peroxidase activity. Data analysis showed that the factors significantly affecting tissue Se concentration include type of chicken (P=0.006), type of tissue (P<0.001) and the analytical method used (P=0.014). Although Se source was not found to affect tissue Se concentration (overall P>0.05), certain inorganic (sodium selenite), calcium selenite, sodium selenate and organic sources (B-Traxim Se), Se-yeast, Se-malt, Se-enriched cabbage and Se-enriched garlic as well as background Se level from feed ingredients were found to significantly affect tissue Se concentration. The Se accumulation rate (estimated as linear regression coefficient of Se concentrations to Se added to feed) discriminated between the various tissues with highest values estimated in the leg muscle and lowest in blood plasma. Correlation analysis has also shown that tissue Se concentration (pooled data) was correlated to Se added to feed (r=0.529, P<0.01, log values) and to glutathione peroxidase activity (r=0.332, P=0.0478), with the latter not being correlated with Se added to feed. Although significant factors affecting Se concentration were reported in the present study, they do not necessarily indicate the in vivo function of the antioxidant system or the level of accumulated Se as other factors, not examined in the present study, may interact at the level of trace element absorption, distribution and retention.

Severe disease outbreaks of erysipelas in poultry flocks are caused by infection with the bacterium Erysipelothrix rhusiopathiae. This disease occurs in a wide range of poultry, including turkey, broiler chicken, hen, goose, and pheasant flocks. Erysipelas usually follows an acute course in birds, in the form of sepsis. Infections with E. rhusiopathiae occur through damaged skin or mucous membranes. The symptoms that occur just before death include unsteady locomotion and a lack of coordinated movement. A chronic form of bacterial infection primarily occurs in turkeys that have been vaccinated against erysipelas, and, in addition to affecting the joints, endocarditis can occur. Usually, carcasses are in good condition and correctly muscled, although ecchymosis might be visible in subcutaneous fat and thigh muscles, while internal organs become enlarged, such as the liver, spleen and kidneys. Histopathological tests indicate major vascular changes in the parenchymatous organs. Points of necrosis related to the infarctions of the large vessels are rarely observed, whereas spilled degenerative changes of parenchymatous organs are more likely to be observed. Turkeys are the only species of poultry for which vaccines against erysipelas have been registered; however, this vaccination is also effective for other poultry. E. rhusiopathiae is mainly sensitive to penicillin, but also responds to cephalosporins, tetracyclines, quinolines, clindamycin, erythromycin, and piperacillin.

Bioactive peptides are specific protein fragments that positively impact the body's function or condition and ultimately may influence health. These peptides are inactive within the sequence of the parent protein and can be released during proteolysis or fermentation. They may exert a number of different activities in vivo, affecting cardiovascular, endocrine, immune and nervous system in addition to nutrient utilization. Hen eggs have traditionally been recognized as an excellent source of protein, vitamins and minerals. Research in the past decade, however, has produced a substantial amount of evidence indicating that hen egg proteins and peptides may exert several diverse biological effects, above and beyond fulfilling basic nutritional requirements. Several biological activities have now been associated with hen egg proteins, including novel antimicrobial activities, immunomodulatory, anti-cancer, and anti-hypertensive activities, highlighting the importance of hen egg proteins in human health, and disease prevention and treatment. Continued research to identify new and existing biological functions of hen egg proteins and their derivatives will help to define new methods to further improve the value of eggs, as a source of numerous biologically active compounds with specific benefits for human and animal health, and secure their role in the therapy and prevention of chronic and infectious disease.

Velvet beans (Mucuna spp.) represent a group of legumes that was widely grown in the U.S. in the 1800's and early 1900's before being replaced by soybeans. However today, in developing countries, the velvet bean plant is increasingly used as a cover crop because it has many valuable characteristics, such as resistance to insects, weeds and drought that make it economically useful to subsistence farmers. The velvet bean plant is also prolific in seed production, and velvet bean seeds (VB) or Mucuna are sometimes eaten both by humans and other non-ruminant, monogastric animals such as chickens and pigs. Mucuna beans contain moderate amounts of protein (20–25%) and smaller amounts of fat (3–5%). Non-structural carbohydrates make up approximately half of Mucuna while the neutral detergent fibre content is about 10%. Minerals and vitamins in VB can contribute significantly to the needs of poultry as is typical of many legumes. The various species of Mucuna have amino acid profiles similar to other legumes, such as soybeans, that are commonly used as protein-supplying feedstuffs. However, VB contain a variety of anti-nutritional/toxic factors that are harmful to monogastric animals. These include: antitrypsin factors; tannins; cyanide; anticoagulants; analgesic, antipyretic and anti-inflammatory factors; L-dopa and others. Research to date has studied the physiological effects of VB on poultry growth, blood chemistry and organ anatomy. Attempts have been made to process the beans and remove the toxic factors by heating, waterextraction or other methods but with limited success. To use such a potentially valuable feed ingredient in poultry nutrition, the challenge for the nutritionist is to find ways to diminish the harmful effects of the chemicals in Mucuna by processing or treating the beans to remove or render harmless the toxic chemicals. This review will summarize the history of these efforts.

The eggshell of the hen is a highly ordered, mineralised structure deposited within an acellular milieu – the uterine fluid secreted by the distal oviduct. Spherulitic crystal growth is initiated by deposition of calcium carbonate on aggregates of organic material present on the outer surface of the eggshell membranes. Gel electrophoresis reveals a complex array of proteins in uterine fluid and eggshell extracts. The eggshell matrix proteins can be classified as egg white proteins (lysozyme, ovalbumin, ovotransferrin, clusterin), bone protein (osteopontin), or proteins specific to the uterus and eggshell (ovocleidins-17 and –116; ovocalyxins-32 and –36). Eggshell extracts, uterine fluid and purified fractions are able to modify the morphology of calcite crystals in vitro. In young hens the breaking strength of the eggshell is inversely related to the degree of calcite orientation. Conversely, reduced strength in eggshell from aged hens coincides with a high variability in crystallographic texture. In guinea fowl the exceptional mechanical properties of the eggshell are explained by an increase in the amount of eggshell produced and particular features of the crystallographic texture. These observations suggest that the eggshell matrix influences the process of crystal growth by controlling size, shape and orientation of calcite crystals. This structural control probably contributes in a substantial manner to the mechanical properties of eggshell.