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In free-range and organic production systems, hens can make choices according to their needs and desires, which is in accordance with welfare definitions. Nonetheless, health and behavioral problems are also encountered in these systems. The aim of this article was to identify welfare challenges observed in these production systems in the EU and the most promising solutions to overcome these challenges. It is based on a review of published literature and research projects complemented by interviews with experts. We selected EU specific information for welfare problems, however, the selected literature regarding solutions is global. Free range use may increase the risk of infection by some bacteria, viruses and parasites. Preventive methods include avoiding contamination thanks to biosecurity measures and strengthening animals' natural defenses against these diseases which can be based on nutritional means with new diet components such as insect-derived products, probiotics and prebiotics. Phytotherapy and aromatherapy can be used as preventive and curative medicine and vaccines as alternatives to antibiotics and pesticides. Bone quality in pullets and hens prevents keel deviations and is favored by exercise in the outdoor range. Free range use also lead to higher exposure to variable weather conditions and predators, therefore shadow, fences and guard animals can be used to prevent heat stress and predation respectively. Granting a free range provides opportunities for the expression of many behaviors and yet many hens usually stay close to the house. Providing the birds with trees, shelters or attractive plants can increase range use. Small flock sizes, early experiences of enrichment and personality traits have also been found to enhance range use. Severe feather pecking can occur in free range production systems, although flocks using the outdoor area have better plumage than indoors. While many prevention strategies are facilitated in free range systems, the influence of genetics, prenatal and nutritional factors in free range hens still need to be investigated. This review provides information about practices that have been tested or still need to be explored and this information can be used by stakeholders and researchers to help them evaluate the applicability of these solutions for welfare improvement.

This paper focuses on systems producing short rotation coppice willows (SRCW) in chickens’ free-range areas. We aim to map chicken farmers’ motivation to implement SRCW, and to assess the economic viability of these systems. Semi-structured interviews were conducted with 18 free-range chicken farmers. Farmers agreed that chickens would prefer SRCW over grassland, which could benefit chicken welfare. They expected establishing an SRCW system would be labor intensive, and doubted if it would be a profitable investment. Some concerns of farmers might be taken away by exchanging information with farmers with SRCW experience. A partial budget analysis was performed to calculate the net present value (NPV) of six different scenarios, differing in the type of chickens, in whether the produced biomass was sold or valorized on-farm and in harvest pattern, all over a 23-yr period. The NPV was positive but low for all scenarios. A sensitivity analysis showed that changes in biomass yield, wood chip price, a price premium for poultry products and current fuel price were most likely to influence the NPV. A risk analysis revealed that NPVs were positive in the majority of the modeled cases. Scenarios in which biomass was used for on-farm heat production showed the highest risk of a negative NPV. A price premium for poultry products may be most effective at increasing profitability, but may only be feasible for farms selling directly to consumers. Establishing a solid market for biomass energy, including guaranteed demand and availability of appropriate machinery for cultivation, may mitigate farmers’ concerns.

European farms for broiler breeders often have raised slatted areas in front of the nests, but in other regions of the world no raised slatted areas are provided. This study aimed to investigate the effects of a raised slatted area on leg health, mating behaviour and floor laying behaviour. Ten groups of 33 broiler breeder hens and three males were housed in two pen types: with or without a raised slatted area in front of the nests. Each pen had one plastic and one wooden nest. Between 25 and 31 weeks of age, ten marked hens per pen were weighed and assessed weekly on foot pad dermatitis, hock burn and wounds. At the end of week 31, animals were euthanized and bone strength of the tibia and humerus of these individuals was assessed. At 24, 27 and 30 weeks of age, mating behaviour was observed for an hour per pen, noting both numbers of successful and unsuccessful copulations. The number of eggs laid in the nests and on the floor was recorded daily between 20 and 31 weeks of age. Foot pad dermatitis scores were affected by age, but not by pen type. Generally, there were only minor issues with foot pad dermatitis (scores < 11 on a 0–100 scale), probably due to the young age of the hens. Body weight was not affected by pen type, while the prevalence of hock burns was too low to analyse and no difference in bone strength was found for the tibia and the humerus. Overall, mating behaviour was less frequent in pens with raised slats than in pens without raised slats (29 ± 2 vs 35 ± 3 times/h) and more frequent at 27 weeks of age than at 24 and 30 weeks of age (38 ± 1 vs 31 ± 4 and 27 ± 2 times/h). The pens with raised slats had a lower percentage of floor eggs than pens without raised slats (11.2 ± 0.4 vs 19.3 ± 0.5%). The wooden nest was preferred over the plastic nest as on average 63% of the eggs were laid in the wooden nest. This study shows that providing raised slats decreases mating behaviour and percentage of floor eggs, although its effects on leg health remain inconclusive.

Free-range use by broiler chickens is often limited, whereas better use of the free-range area could benefit animal welfare. Use of free-range areas could be stimulated by more appropriate shelter or environmental enrichment (by decreasing birds’ fearfulness). This study aimed to assess the effects of shelter type, early environmental enrichment and weather conditions on free-range use. Three production rounds with 440 slow-growing broiler chickens (Sasso T451) were carried out. Birds were housed indoors in four groups (two with males, two with females) from days 0 to 25, during which two of the groups received environmental enrichment. At day 23 birds’ fearfulness was assessed with a tonic immobility (TI) test (n=100). At day 25 all birds were moved (in mixed-sex groups) to mobile houses, and provided with free-range access from day 28 onwards. Each group could access a range consisting for 50% of grassland with 21 artificial shelters (ASs, wooden A-frames) and for 50% of short rotation coppice (SRC) with willow (dense vegetation). Free-range use was recorded by live observations at 0900, 1300 and 1700 h for 15 to 21 days between days 28 and 63. For each bird observed outside the shelter type (AS or SRC), distance from the house (0 to 2, 2 to 5, >5 m) and its behaviour (only rounds 2 and 3) were recorded. Weather conditions were recorded by four weather stations. On average, 27.1% of the birds were observed outside at any given moment of observation. Early environmental enrichment did not decrease fearfulness as measured by the TI test. It only had a minor effect on the percentage of birds outside (0.4% more birds outside). At all distances from the house, SRC was preferred over AS. In AS, areas closer to the house were preferred over farther ones, in SRC this was less pronounced. Free-range use increased with age and temperature and decreased with wind speed. In AS, rainfall and decreasing solar radiation were related to finding more birds outside, whereas the opposite was true in SRC. Behaviour of the birds depended on shelter type, distance from the house, early environmental enrichment, time of day and age. Chickens ranged more and farther in SRC, possibly because this provided a greater sense of safety because of the amount of cover and/or better protection against adverse weather conditions. These results indicate that SRC with willow is a more appropriate shelter for slow-growing broiler chickens than A-frames.

Feather pecking is a multi-factorial behavioral disorder and a serious welfare issue in the poultry industry. Several studies report early life experience with litter to be a major determinant in the development of feather pecking. The current study aimed to test the large-scale on-farm efficiency of a simple and cheap husbandry procedure applied during the rearing period with the ultimate goal of reducing the incidence of feather pecking and plumage damage during the production stage in laying hens. Five laying hen-rearing farmers from across Norway participated in the study. These farmers were asked to create divisions within their hen rearing houses and to separate their chicks into 2 groups: one reared with access to a paper substrate from the first d of age, the other a control group without access to paper substrate during rearing. All flocks were visited at the production farms at 30 wk of age and observed for pecking behavior and feather damage. Birds in the control group had higher odds of having more feather damage compared to the birds from the treatment group. In addition, flocks provided with environmental enrichment at the production farms had a reduced incidence of feather pecking, irrespective of the treatment. These results indicate that husbandry procedures during both rearing and production stages have the potential to alleviate feather pecking and increase laying hen welfare.

Non-cage systems provide laying hens with considerable space allowance, perches and access to litter, thereby offering opportunities for natural species-specific behaviors. Conversely, these typical characteristics of non-cage systems also increase the risk of keel bone and foot pad disorders. The aim of this study was twofold: 1) to investigate if providing ramps between perches (housing factor) reduces keel bone and foot pad disorders and 2) to test for genetic predisposition by comparing 2 different layer hybrids. In a 2 × 2 design, 16 pens were equipped either with or without ramps between perches and nest boxes (8 pens/treatment), and housed with either 25 ISA Brown or Dekalb White birds per pen (in total 200 birds/hybrid). Keel bone injuries and foot health were repeatedly measured via palpation and visual assessment between 17 and 52 wk of age and daily egg production was recorded. The relationships between the dependent response variables (keel bone and footpad disorders, egg production) and independent factors (age, ramps, hybrid) were analyzed using generalized linear mixed models and corrected for repeated measures. Ramps reduced keel bone fractures (F1,950 = 45.80, P

Genetic selection for highly efficient, fast-growing broilers has had negative effects on broiler welfare, and the high stocking densities used in some broiler production systems also have a negative impact on welfare. This chapter examines the welfare problems arising from these two factors, and reviews how both factors have been addressed within the European Union. Two case studies are then provided, examining the welfare effects of hatching environment and early feeding, and of alternative broiler production systems

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.

Studies on the prevalence of feather pecking in different commercial laying hen 23 systems and its welfare and economic impacts are reviewed in the following paper. 24 Current methods for controlling feather pecking include beak-trimming and alterations to light regimes, but these methods have significant disadvantages from the perspective of bird welfare. A substantial body of research has now identified risk factors for feather pecking during both the rearing and laying periods. It is argued that these findings can be translated into optimised management practices that can prevent and control feather pecking whilst simultaneously conferring welfare benefits. The genetic basis of feather pecking is considered, and studies that suggest group selection techniques could produce birds with a reduced tendency to feather peck in commercial flocks are highlighted. Keywords: laying hen; feather pecking; beak-trimming; light; risk factor; genetic selection

The European Union 1997 Directive, stipulating that veal calves should be fed a minimum of 50 to 250 g of fibrous feed from 8 to 20 wk of age, is vague. A fibrous feed ration maximum of 250 g has been implicated in welfare issues, namely the occurrence of abnormal oral behaviors and poor gastrointestinal health. Past research suggests that this amount is insufficient to prevent the development of abnormal oral behaviors and enabling good rumen development. Different sources and particle sizes of roughage could lead to very different welfare outcomes. In a 3 × 2 × 2 factorial design, 240 group-housed calves (10 ± 1 d; 46.1 ± 0.1 kg) were fed different roughage sources (straw, maize silage, or maize cob silage; the latter 2 were dried and provided no extra moisture compared with straw) in 2 amounts (250 or 500 g of dry matter per day), and 2 particle sizes (chopped or ground). Roughage was supplemented to milk replacer (MR) from 2 wk after arrival. In addition, 60 calves were fed 1 of 3 additional control treatments: MR only (n = 20), MR plus an iron supplement (n = 20), or MR plus ad libitum hay (n = 20). Oral behaviors were recorded using instantaneous scan sampling at 2-min intervals for 2 h in 3 periods per day, at 12 and 22 wk of age. Calves were slaughtered at 24 wk of age and rumen and abomasal health parameters were recorded. Limited provision of straw resulted in behavior comparable with that from unlimited provision of hay, with reduced tongue playing and oral manipulation of the environment, as well as increased chewing compared with diets with no roughage supplement. Straw prevented ruminal hairballs, but impaired rumen development and increased abomasal damage. A higher ration of roughage increased chewing (12 wk), decreased oral manipulation of the trough (12 and 22 wk) and the pen (22 wk), and increased rumen weight. However, more roughage led to increased abomasal damage for certain parameters. Longer feed particles had no obvious benefits for behavior, but decreased hairball prevalence. Overall, unlimited hay had the highest benefit for both behavior and gastrointestinal health. Adding iron to the MR did not alter behavior or gastrointestinal health compared with MR without iron supplement. This study demonstrated that different roughage sources, amounts, and particle sizes have different effects on veal calf behavior and gastrointestinal health, and hence on veal calf welfare. Key words: veal calf , behavior , gastrointestinal health , roughage

Pigs housed together in a group influence each other's growth. Part of this effect is genetic and can be represented in a social breeding value. It is unknown, however, which traits are associated with social breeding values. The aim of this study was, therefore, to investigate whether personality and response to novelty could be associated with social breeding values for growth in piglets. Female and castrated male piglets from 80 litters, with either an estimated relative positive or negative social breeding value (+SBV or -SBV) for growth, were individually tested in a backtest and novel environment test, and group-wise in a novel object (i.e., a feeder with feed) test and human approach test. All tests were performed during the suckling period. No differences between +SBV and -SBV piglets were found for the frequency and latency of struggling and vocalizing in the backtest (at least, P > 0.30). In the novel object test, piglets with a +SBV for growth touched the feeder faster than piglets with -SBV for growth (P = 0.01) and were more frequently present near the person in the human approach test (P 0.40), but piglets that struggled more in the backtest walked more in this test (P = 0.02). Behavior was affected by gender in each test. Female piglets were faster than castrated male piglets to start struggling in the backtest (P = 0.047). In the novel object test, females were faster than males to touch the feeder and sample the feed. In the human approach test, they were also faster than male piglets to touch a person (all, P < 0.001). Females were also more frequently present near the feeder (P < 0.001) and person (P = 0.03). In the novel environment test, female piglets explored the floor more (P = 0.046), produced less low- (P = 0.04) and high-pitched vocalizations (P = 0.02), and defecated (P = 0.08) and urinated less than male piglets (P < 0.01). It was concluded that +SBV and -SBV piglets do not differ in their response to the backtest, and only subtle differences were found in their response to novelty. More research is warranted to identify the traits underlying SBV for growth in pigs. Moreover, castrated male piglets seemed to react more fearfully to each test than female piglets.

Little is known about the relationship between welfare traits and production in laying hen parent stock (PS). In commercial laying hens and pure lines, it is known that aspects associated with reduced welfare such as high fear, stress, and feather pecking can have negative effects on production. Because PS hens are housed under different conditions than commercial laying hens, the relationship between welfare traits and production may differ. We therefore studied the fear response to a stationary person (SP) and novel object (NO), basal plasma corticosterone (CORT) and whole-blood serotonin levels (5-HT), and feather damage as a proxy for feather pecking in 10 Dekalb White (DW) and 10 ISA Brown (ISA) commercial PS flocks and related these to production data. Because the relationship between welfare traits and production may differ by genetic origin and group size, we also assessed genotype and group size effects. Dekalb White birds were more fearful of a SP, and had more feather damage and lower 5-HT levels than ISA birds. Genotypes did not differ in CORT. A large group size (n > 5,000) was associated with low feed intake and better feed conversion for ISA flocks. For DW flocks, high fear of the NO was associated with low BW, low egg weight, and low feed intake. For ISA flocks, high fear of the SP was associated with high mortality. For both lines, high CORT was related to low egg weight. This is the first study to associate levels of fear and CORT to production in commercial PS flocks. Management of PS flocks should take into account breed differences, group size effects, and effects of human-bird interactions. Further research is needed to determine the effects of fear, CORT, 5-HT, and feather damage in commercial PS flocks on the development of their offspring.

To sustainably contribute to food security of a growing and richer world population, livestock production systems are challenged to increase production levels while reducing environmental impact, being economically viable, and socially responsible. Knowledge about the sustainability performance of current livestock production systems may help to formulate strategies for future systems. Our study provides a systematic overview of differences between conventional and organic livestock production systems on a broad range of sustainability aspects and animal species available in peer-reviewed literature. Systems were compared on economy, productivity, environmental impact, animal welfare and public health. The review was limited to dairy cattle, beef cattle, pigs, broilers and laying hens, and to Europe, North America and New Zealand. Results per indicators are presented as in the articles without performing additional calculations. Out of 4171 initial search hits, 179 articles were analysed. Studies varied widely in indicators, research design, sample size and location and context. Quite some studies used small samples. No study analysed all aspects of sustainability simultaneously. Conventional systems had lower labour requirements per unit product, lower income risk per animal, higher production per animal per time unit, higher reproduction numbers, lower feed conversion ratio, lower land use, generally lower acidification and eutrophication potential per unit product, equal or better udder health for cows and equal or lower microbiological contamination. Organic systems had higher income per animal or full time employee, lower impact on biodiversity, lower eutrophication and acidification potential per unit land, equal or lower likelihood of antibiotic resistance in bacteria and higher beneficial fatty acid levels in cow milk. For most sustainability aspects, sometimes conventional and sometimes organic systems performed better, except for productivity, which was consistently higher in conventional systems. For many aspects and animal species, more data are needed to conclude on a difference between organic and conventional livestock production systems.

Feather pecking and cannibalism in farm-kept laying hens are damaging behaviors both in terms of animal welfare and economic loss, and a major challenge in modern poultry farming. Both rearing with a foster hen and genetic selection have been demonstrated to reduce feather pecking in laying hens. We examined the effects of rearing with a foster hen, genetic selection for low mortality from cannibalism, and interactions between both, using cellular morphology and levels of the rate-limiting enzyme in dopamine production, tyrosine hydroxylase, in the hippocampus and nidopallium caudolaterale (NCL) as a potential measure for laying hen welfare. Hens from the second generation of a sib-selection scheme line derived from a pure-bred White Leghorn line, selected for low mortality and for production characteristics, or their control line (CL) selected only for production characteristics, were housed with or without a foster Silky hen for the first 7 wk of life. Aside from the presence or absence of a foster Silky hen during the first 7 wk of life, housing conditions were identical for all hens. The hens were then sacrificed and brains were removed at 52 wk of age. Brains were sectioned and stained using a Nissl staining to reveal cell soma morphology, or using immunocytochemistry for tyrosine hydroxlase. A greater degree of lateralization in the hippocampus was observed in hens reared without a foster hen, as measured by absolute difference in cell soma size between hemispheres (P

It is the expectation that the world population will grow to 9 billion people by 2050. There is no doubt that this dramatic increase will impact all of the animals with which we share this planet. A global population growing in size and affluence will greatly increase demand for food from animal sources, meaning global growth in livestock production. More livestock production means changes in land use, with more land being converted to grazing or animal feedstuff production, and more production of waste to be applied back to the land, together impacting natural habitats and wildlife species diversity. Greater affluence also means greater companion animal ownership, further increasing demand for food from animal sources, increasing feral populations with potential impacts on human health and wildlife diversity. In this chapter, we will attempt to gaze into the crystal ball and identify some future directions for applied ethology and for our Society. There is no doubt that applied ethologists can have exciting roles to play in shaping and safeguarding the welfare of domestic animals and wild animals in captivity, and also feral and wild animals living in their natural habitat, either impacting or being impacted by humans

Purebred laying hen lines of White Leghorn (WL) origin have been found to be more flighty and to show more feather pecking than lines of Rhode Island Red (RIR) origin. It has been found, however, that when RIR birds were housed together with WL birds, RIR birds became more flighty and those mixed groups developed more feather damage than pure-line cage-housed groups. It is unknown, however, whether this effect of social environment is accompanied by changes in stress-related behavior and neurophysiological activity, which are assumed to be associated with increased feather damage. The objective of this study was therefore to investigate the effects of genetic origin (WL or RIR) and social environment (mixed or pure groups) on behavioral response to manual restraint and monoamine functioning. Monoamine functioning was measured by brain serotonin (5-HT) and dopamine turnover. Furthermore, correlations between 5-HT turnover in the brain and peripheral measures of 5-HT in the blood were calculated. Experimental birds, housed either with other birds from the same genetic origin (pure groups) or with both RIR and WL birds (mixed groups) from hatching onward, were subjected to a manual restraint test at 47 wk of age. The WL birds struggled less during restraint and had higher dopamine and 5-HT turnover levels after restraint than did RIR birds. The WL birds also showed higher levels of platelet 5-HT uptake than did RIR birds. No effects of social environment were found. Blood and brain 5-HT measures were found to be correlated, with correlations ranging from 0.34 to 0.57, which seems to offer opportunities for less invasive peripheral indicators of 5-HT activity. In conclusion, genetic origin, but not social environment, affected the behavioral response to manual restraint and monoamine functioning in laying hens.

Recent studies showed that laying hens learn not to peck at bitter-tasting feathers from conspecifics. In the present experiment, feathers of newly hatched chicks were made distasteful by spraying them with a bitter-tasting substance (quinine). It was hypothesized that chicks could detect quinine and learn to avoid the downy feathers and the feathers of conspecifics later in life. Six groups of 10 high feather-pecking birds and six groups of 10 low feather-pecking birds were kept on litter. Half of each of these groups was quinine treated. Each bird in the quinine-treated groups was individually sprayed on a weekly basis for 25 weeks with a quinine solution. It was investigated whether the presence of quinine on the birds’ feather cover affected gentle and severe feather pecking. The result indicated that feathers made distasteful with quinine reduced severe feather pecking in young and adult birds as long as it was detected on birds feather cover.

Aviary systems for laying hens offer space and opportunities to perform natural behaviors. However, hen welfare can be impaired due to increased risk for keel bone and foot pad disorders in those systems. This cross-sectional study (N = 47 flocks) aimed to assess prevalences of keel bone and foot pad disorders in laying hens housed in aviaries in Belgium to identify risk factors for these disorders and their relation to egg production. Information on housing characteristics and egg production were obtained through questionnaire-based interviews, farm records, and measurements in the henhouse. Keel bone (wounds, hematomas, fractures, deviations) and foot pad disorders (dermatitis, hyperkeratosis) were assessed in 50 randomly selected 60-week-old laying hens per flock. A linear model with stepwise selection procedure was used to investigate associations between risk factors, production parameters, and the keel bone and foot pad disorders. The flock mean prevalences were: hematomas 41.2%, wounds 17.6%, fractures 82.5%, deviations 58.9%, hyperkeratosis 42.0%, dermatitis 27.6%, and bumble foot 1.2%. Identified risk factors for keel bone disorders were aviary type (row vs. portal), tier flooring material (wire mesh vs. plastic slats), corridor width, nest box perch, and hybrid. Identified risk factors for foot pad disorders were aviary type (row vs. portal), free-range, and hybrid. Percentage of second-quality eggs was negatively associated with keel bone deviations (P = 0.029) at the flock level. Keel bone and foot pad disorders were alarmingly high in aviary housing. The identification of various risk factors suggests improvements to aviary systems may lead to better welfare of laying hens.

Sustainable livestock production systems are needed to feed the larger, more urban, richer and older world population in 2050. Quantitative information about the sustainability performance of existing livestock production systems can aid the debate of which actions could be developed and implemented. Strong points of conventional and organic dairy cattle, beef cattle, pig, laying hen, and broiler production systems were identified in peer-reviewed literature for a limited number of sustainability indicators within the subjects of economy, productivity, environment, animal welfare, and public health. This study aims to identify lessons learned for sustainable livestock production.

International audience; Exposure of laying hens to chronic heat stress results in loss of egg production. It should be possible to improve hen resilience to chronic heat stress by genetic selection but measuring their sensitivity through internal temperature is time consuming and is not very precise. In this study we used infrared thermography to measure the hen’s capacity to dissipate heat, in a commercial line of laying hens subjected to cycles of neutral (N, 19.6°C) or high (H, 28.4°C) ambient temperatures. Mean body temperatures (BT) were estimated from 9355 infrared images of wing, comb and shank taken from 1200 hens. Genetic parameters were estimated separately for N and H temperatures. Correlations between BT and plumage condition were also investigated. Wing temperature had low heritability (0.00 to 0.09), consistent with the fact that wing temperature mainly reflects the environmental temperature and is not a zone of heat dissipation. The heritability of comb temperature was higher, from 0.15 to 0.19 in N and H conditions, respectively. Finally, the shank temperature provided the highest heritability estimates, with values of 0.20 to 0.22 in H and N conditions, respectively. Taken together, these results show that heat dissipation is partly under genetic control. Interestingly, the genetic correlation between plumage condition and shank and comb temperatures indicated that birds with poor condition plumage also had the possibility to dissipate heat through featherless areas. Genetic correlations of temperature measurements with egg quality showed that temperatures were correlated with egg width and weight, yolk brightness and yellowness and Haugh units only under H conditions. In contrast, shell colour was correlated with leg temperature only at thermo-neutrality.

Methods available to assess animal welfare at farm level are based on a range of welfare parameters, which can be divided into two categories, environment-based and animal-based parameters. The first category describes features of the environment and management, which can be considered prerequisites for welfare. The second category records animals' responses to that particular environment and management more directly. Objective of this study was to validate a mainly environment-based method, the animal needs index (ANI), with animal-based methods: behavioural observations and feather condition scores (FCS). The study was conducted on 20 commercial laying hen farms, 10 farms with battery cages and 10 farms with deep litter systems. During a 1-day visit on each farm, ANI was assessed, FCS was scored, and behavioural observations were performed. Instantaneous scan sampling and continuous focal sampling were used to assess the time spent on different behaviours and the occurrence of event behaviours. Data from behavioural observations and FCS were reduced with principal factor analysis. This resulted in two factors for each method. Significant positive correlations were found between ANI, on the one hand, and 'movement' and 'comfort', two factors from behavioural observations, on the other hand. A significant negative correlation was found between ANI and 'wing damage' (from FCS). The results of this study show that ANI is valid and sensitive enough to show differences in animal welfare between housing systems, whereas differences in welfare within housing systems cannot be shown. In conclusion, ANI is an appropriate method for assessment of laying hen welfare on a large number of farms with different housing systems.

European duck meat production is based on the use of Pekin, Muscovy and Mule duck genotypes that vary in their behavioural and physiological characteristics. Furthermore, large differences exist in their housing and management conditions. The aim of this review is to discuss the welfare of these different genotypes in typical husbandry systems, focusing on ducks kept for meat production. Firstly, factors that can affect duck welfare, such as stocking density and group size, access to straw, an outdoor run, or open water, are described. Secondly, welfare problems such as feather pecking, fear and stress, and health problems are assessed. Thirdly, the various systems used in Europe are described for these aspects. Giving ducks access to straw, an outdoor run, or open water increases the behavioural opportunities of the ducks (foraging, preening, bathing, and swimming), but can also lead to poor hygiene and increased health- and food safety risks. Therefore, practical solutions that allow expression of natural behaviour, but do not lead to hygiene or health problems have to be found and some practical suggestions are provided

Broiler chickens, Gallus gallus domesticus, have been selected for rapid weight gain and appear to be continously hungry. If this is so, then energy that broilers invest in obtaining food should be insensitive to their level of feed restriction. We tested this hypothesis by measuring the maximum price (i.e. maximum number of key pecks) broilers with different body weights would pay for a food reward under conditions of varying feed restriction. Two groups of 20 broilers were fed on 50 or 75% of the amount of feed a broiler would eat when fed ad libitum. Broilers were able to learn an operant task and were willing to work for food. Birds of the 50%-group paid a higher maximum price for a food reward and responded more quickly to food presentation than the birds of the 75%-group in the first test week and showed a nonsignificant tendency to pay a higher price and to respond more quickly in the second test week. Different levels of long-term feed restriction had an influence on their body weight and on their motivation to work for food. No short-term effect of changing feed restriction was found. Birds showed frustration behaviour after the last food reward had been obtained, indicating that they were still hungry. The results indicate that broilers are still sensitive to different levels of feed restriction and that they can balance their investments and profits to a certain extent.

The effect of rearing conditions on feather pecking and reaction to frustration was studied in two lines of laying hens. From commercial rearing conditions (large group, no mother hen), seven birds from a high feather pecking line (HC birds) and eight birds from a low feather pecking line (LC birds) were used. From semi-natural rearing conditions (small group, mother hen present) seven birds from the high feather pecking line (HN birds) were used. Feather pecking behaviour of HC, LC, and HN groups was recorded for 30 min. After that, each bird was food deprived and trained to peck a key for a food reward in a Skinnerbox. After training, each bird was subjected to a frustration session in a Skinnerbox, where the feeder was covered with Perspex. Three HC birds showed severe feather pecking, compared with one HN bird and zero LC birds. Differences in reaction to frustration were found between birds from different lines, but not in birds from different rearing conditions. LC birds tended to put their head in the feeder more frequently than HC birds over all sessions. Although limited, this study indicates that rearing conditions influence feather pecking, but not reaction to frustration.

Organic poultry production in the Netherlands is developing. Although consumers assume organic products to be safer and healthier, there are aspects of organic animal husbandry, like access to an outdoor run, that can result in increased risks of food safety problems. The aim of this study was to compare housing and management of organic and conventional broiler farms in the Netherlands and to study the occurrence of Salmonella and Campylobacter infections on the former. Large differences were found between the two farming systems with respect to mixed or single farming, manure storage, drinking-water system, ventilation, access to an outdoor run, and pest control. From the 31 organic flocks sampled for Salmonella and Campylobacter in 2003, 13% were positive for Salmonella and 35% for Campylobacter. Results for the summer period are missing due to an outbreak of avian influenza, so the actual number of flocks infected with Campylobacter can be expected to be even higher. Campylobacter appears to be the main risk on organic broiler farms, so that it would be interesting to study specific risk factors of infection with this pathogen on these farms.

The object of this research was to study the relationship between feather pecking and open-field activity in laying hens at two different ages. A population of 550 birds of a laying hen cross was subjected to an open-field test at 5 and 29 weeks of age and to a social feather pecking test at 6 and 30 weeks of age. Factor analysis was used to identify underlying factors for each test: pecking behavior ( social test) and open-field activity (open-field test). In young birds, a positive phenotypic correlation of 0.24 was found between high open-field activity and high levels of pecking behavior ( ground pecking, preening, gentle feather pecking, and wall pecking). In adults, a similar genetic correlation of 0.62 was found. At adult age, the factor pecking behavior consisted mainly of gentle and severe feather pecking. Between ages, a strong, negative genetic correlation of - 0.65 was found between open-field activity at young age and pecking behavior at adult age, indicating that open-field activity levels in young birds may predict pecking behavior in adult hens.

In the European Union, legislation concerning animal housing is becoming stricter because of animal welfare concerns. Feather pecking (FP) in large group housing systems is a major problem. It has been suggested that corticosterone (CORT) response to manual restraint as a measure for stress is associated with FP behavior. The aim of the current study was to identify QTL involved in FP behavior and stress response in laying hens. An F-2 population of 630 hens was established from a cross between two commercial lines of laying hens differing in their propensity to feather peck. The behavioral traits, measured at 6 and 30 wk of age, were gentle FP, severe FP, and aggressive pecking. Toe pecking was measured at 30 wk of age and CORT response to manual restraint was measured at 32 wk. All animals were genotyped for 180 microsatellite markers. A QTL analysis was performed using a regression interval mapping method. At 6 wk of age, a suggestive QTL on GGA10 was detected for gentle FP. At 30 wk of age, suggestive QTL were detected on GGA1 and GGA2 for gentle FP. A significant QTL was detected on GGA2 for severe FP. At 32 wk of age, a suggestive QTL was detected on GGA18 for CORT response to manual restraint. In addition, a suggestive QTL was detected on GGA5 with possible maternal parent-of-origin effect for CORT response.

Chronic heat is a major stress factor in laying hens and many studies on the effect of heat stress have been published. It remains difficult, however, to draw general conclusions about the effect of chronic heat stress on performance and its relationship with genetic and environmental factors, as these studies have been done under varying experimental conditions and using various experimental designs. A meta-analysis enabled us to make a quantitative review of the results from 131 published papers. The relative effects of four factors (genotype, age, group size, and amplitude of temperature variation) and their interactions with temperature were analyzed for 13 traits. After pre-correcting the data for a random study effect, the best model for each trait was selected in a step-wise procedure based on its residual sum of squares. Shell strength, daily feed intake, egg mass, and hen-day egg production were found to be more sensitive to heat stress than the other traits as they dropped by 9.0 to 22.6% between thermo-neutrality (15 to 20 degrees C) and heat stress (30 to 35 degrees C) while yolk and albumen proportions or Haugh units showed nearly no variation with temperature (

International audience; Background Feather pecking is a major welfare issue in laying hen industry that leads to mortality. Due to a ban on conventional cages in the EU and on beak trimming in some countries of the EU, feather pecking will become an even bigger problem. Its severity depends both on the victim receiving pecking and on its group mates inflicting pecking (indirect effects), which together determine plumage condition of the victim. Plumage condition may depend, therefore, on both the direct genetic effect of an individual itself and on the indirect genetic effects of its group mates. Here, we present estimated genetic parameters for direct and indirect effects on plumage condition of different body regions in two purebred layer lines, and estimates of genetic correlations between body regions.MethodsFeather condition scores (FCS) were recorded at 40 weeks of age for neck, back, rump and belly and these four scores were added-up into a total FCS. A classical animal model and a direct–indirect effects model were used to estimate genetic parameters for FCS. In addition, a bivariate model with mortality (0/1) was used to account for mortality before recording FCS. Due to mortality during the first 23 weeks of laying, 5363 (for W1) and 5089 (for WB) FCS records were available.ResultsTotal heritable variance for FCS ranged from 1.5% to 9.8% and from 9.8% to 53.6% when estimated respectively with the classical animal and the direct–indirect effects model. The direct–indirect effects model had a significantly higher likelihood. In both lines, 70% to 94% of the estimated total heritable variation in FCS was due to indirect effects. Using bivariate analysis of FCS and mortality did not affect estimates of genetic parameters. Genetic correlations were high between adjacent regions for FCS on neck, back, and rump but moderate to low for belly with other regions.ConclusionOur results show that 70% to 94% of the heritable variation in FCS relates to indirect effects, indicating that methods of genetic selection that include indirect genetic effects offer perspectives to improve plumage condition in laying hens. This, in turn could reduce a major welfare problem.

This chapter compares the performance, welfare, health and hygiene of laying hens in different types of non-cage systems, focusing on barn, free range and organic systems. These non-cage systems are compared with each other and with cage systems. This comparison shows that both between barn, free range and organic systems and between non-cage and cage systems large differences can be identified. Moving from conventional cages to furnished cages, barn, free range and finally organic systems results in increasing environmental complexity, which is positive for some aspects of hen welfare, but also increasing risks for performance, health and hygiene, which is negative for other aspects of hen welfare. For the improvement of the welfare of laying hens in non-cage systems and furnished cages, we recommend that the focus should be on creating a better match between the animals and their husbandry environment. Good examples are the development of new housing designs that combine the benefits of non-cage systems with improved performance, health and hygienic status. Further, promising approaches in animal breeding and optimizing rearing environments are expected to yield major improvements in the welfare of laying hens in non-cage systems and furnished cages.

An association study between SNP markers and feather condition score on the back, rump and belly of laying hens was performed. Feather condition score is a measure of feather damage, which has been shown to be closely related to feather pecking behaviour in hens housed in groups. A population of 662 hens was genotyped for 1536 SNPs of which 1022 could be used for the association study. The analysis was conducted across 9 different lines of White Leghorn and Rhode Island Red origin. Across lines linkage disequilibrium is conserved at shorter distances than within lines; therefore, SNPs significantly associated with feather condition score across lines are expected to be closer to the functional mutations. The SNPs that had a significant across-line effect but did not show significant SNP-by-line interaction were identified, to test that the association was consistent across lines. Both the direct effect of the individual’s genotype on its plumage condition, and the associative effect of the genotype of the cage mates on the individual’s plumage condition were analysed. The direct genetic effect can be considered as the susceptibility to be pecked at, whereas the associative genetic effect can be interpreted as the propensity to perform feather pecking. Finally, 11 significant associations between SNPs and behavioural traits were detected in the direct model, and 81 in the associative model. A role of the gene for the serotonin receptor 2C (HTR2C) on chromosome 4 was found. This supports existing evidence of a prominent involvement of the serotonergic system in the modulation of this behavioural disorder in laying hens. The genes for IL9, IL4, CCL4 and NFKB were found to be associated to plumage condition, revealing relationships between the immune system and behaviour.

For laying hens, the effects of housing system on bacterial eggshell contamination and eggshell quality is almost exclusively studied in experimental hen houses. The aim of this study was to compare eggshell hygiene and quality under commercial conditions. Six flocks of laying hens in furnished cages and 7 flocks in noncage systems were visited when hens were about 60 wk of age. Farms from Belgium, the Netherlands, and Germany were included in the study. The following parameters were determined on eggs sampled at the egg belts: 1) bacterial eggshell contamination, as expressed by total count of aerobic bacteria and number of Enterobacteriaceae; 2) proportion of dirty eggs; and 3) proportion of cracked eggs and eggs with microcracks. Considerable within-flock differences were found in eggshell contamination with total count of aerobic bacteria, both for furnished cages (P < or = 0.001, range 4.24 to 5.22 log cfu/eggshell) and noncage systems (P < or = 0.001, range 4.35 to 5.51 log cfu/eggshell). On average, lower levels of contamination with total count of aerobic bacteria (4.75 vs. 4.98 log cfu/eggshell; P < or = 0.001) were found on eggshells from furnished cages compared with noncage systems. Concerning Enterobacteriaceae, no significant difference in average eggshell contamination between both systems could be shown. The total percentage of cracked eggs was higher (P < or = 0.01) in furnished cages (7.8%) compared with noncage systems (4.1%). This was, however, due to the high percentage of cracked eggs (24%) observed on one of the furnished cage farms. We conclude that bacteriological eggshell contamination and percentage of cracked eggs differed substantially between individual farms using the same housing system. This may also explain some discrepancies between the findings of the present study versus some findings of previous experimental studies or studies on a small number of farms. Although statistically significant, the average differences in bacteriological contamination of nest eggs between both housing systems have limited microbiological relevancy.

The aim of the present study was to investigate the effect of brooding and group selection for low mortality on post-stress corticosterone and peripheral serotonin in laying hens. Birds in the experiment originated from the same population and were either group-selected for low mortality (low mortality line) or randomly selected (control line) for two generations. Twelve groups of seven birds from each line were used. Within each line, six groups were brooded by a foster mother and six groups were non-brooded. At 33 weeks of age, birds ( n = 42/treatment) were manually restrained for 5 min, during which their behavioral response (number of struggles) was studied. Fifteen minutes after the start of the manual restraint, blood samples were drawn for assessment of plasma corticosterone and whole blood serotonin (5-HT) concentration. In the low mortality line, 80% of the birds struggled and vocalized vs. 72% in the control line (non significant). Birds from the control line had a higher plasma corticosterone concentration after manual restraint than birds from the low mortality line (7.7 vs. 6.0 nmol ml − 1 ). Furthermore, birds from the control line that were reared without a mother had a lower whole-blood 5-HT concentration than birds from the other treatments (45 vs. 48 nmol ml − 1 ). These results indicate that both brooding and selection for low mortality affect post-stress corticosterone and peripheral serotonin concentration, which may result in a reduced propensity to develop feather pecking.

In laying hens, behavioral responses measured late in the laying period are associated with decreased performance. If measured early in the laying period, these behavioral responses could be used to predict performance later in life. The main objective of the present study was to investigate the association of the behavioral response toward a novel object at 23 wk of age with subsequent performance during the laying period. A total of 1,251 hens from 6 different pure-bred Rhode Island Red lines (208 hens per line on average) were housed in 318 cages (56 cages per line on average). Performance variables included egg production (both per hen-present and hen-housed); BW at 19, 51, and 69 wk of age; mortality; and feather damage at 63 wk. Hens from cages with an approach response realized greater total egg production (hen-day and hen-housed) and greater egg production in the middle (hen-housed) and end of the laying period (per hen present and hen housed) compared with hens from cages with a passive response toward the novel object. Approach responses were also associated with more feather damage, but not with BW or mortality. Low correlations were found between greater egg production and more feather damage. These results suggest that an approach response toward a novel object measured early in the laying period is associated with better performance later in the laying period. The novel object test early in the laying period can be used to predict subsequent performance, although possible causal mechanisms for this association remain to be investigated.

With the introduction of alternative housing systems for laying hens in the EU, recent research has focussed on the bacterial contamination of table eggs, e.g. eggshell and egg content contamination. Contamination of eggshells with aerobic bacteria is generally higher for nest eggs from non-cage systems compared to nest eggs from furnished cages or eggs from conventional cages. Studies indicate limited or no systematic differences in eggshell contamination with aerobic bacteria between eggs laid in the nest boxes of furnished cages and eggs laid in conventional cages. The major differences found in experimental studies between cage- and non-cage systems are less pronounced under commercial conditions. The effect of housing system on eggshell contamination with specific groups of bacteria is variable. Limited information is available on the influence of housing system on egg content contamination. Recent research does not indicate large differences in egg content contamination between eggs from cage- and non-cage systems (ignoring outside nest and floor eggs). The microflora of the eggshell is dominated by Gram-positive bacteria, whereas Gram-negative bacteria are best equipped to overcome the antimicrobial defences of the egg content. Much of the research on eggshell and egg content contamination focuses on Salmonella, since infection with Salmonella enteritidis, resulting from the consumption of contaminated eggs or egg products, is still a major health problem. Observed Salmonella prevalence on the eggshell and in the egg content vary, depending on the fact whether investigations were based on randomly sampled table eggs or on eggs from naturally infected hens. The limited information available on other pathogens shows that they are exclusively isolated from the eggshell and not from the internal contents.

Birds from Rhode Island Red (RIR) origin show a lower fear response and less feather pecking than birds from White Leghorn (WL) origin. This study investigated whether responses in fear eliciting tests were affected if RIR and WL birds were housed together. Experimental groups contained either birds from one line only ('pure' groups) or an equal number of RIR and WIL birds ('mixed' groups). These arrangements were maintained from hatch onwards, throughout the rearing and laying period. Birds were subjected to open held tests at 5-6 weeks and 17-18 weeks of age and to manual restraint tests at 7-8 weeks and 24 weeks of age. RIR birds were more active in both open field tests and in the manual restraint test at 24 weeks of age as compared with WL birds. RIR birds from pure groups were more active in the open field test at 17-18 weeks and in the manual restraint test at 24 weeks of age than RIR birds from mixed groups. These results suggest that otherwise low fearful RIR birds may adopt a higher fear response if they are housed together with more fearful conspecifics. These effects do not emerge until after 8 weeks of age. Published by Elsevier B.V.

International audience; 1. The aim of this study was to assess the feasibility of 100% organic feed for organic broilers by comparing it with 80% organic feed (situation at the time of the experiment; 2004) and 95% organic feed (alternative). 2. Diets were optimised for nutritional value, allowing a maximum 10% increase in feed price when using 100% organic feedstuffs. This could only be achieved at the expense of the methionine content. 3. The broilers were reared from zero to three weeks of age in a broiler house in three groups of 500 broilers each on either an 80-, a 95-, or a 100% organic starter diet. At three weeks of age, the broilers were transferred to 15 pens with an outdoor run. Each treatment group of 500 broilers was divided into five groups of 95 broilers and fed an 80-, a 95, or a 100% organic finisher diet. 4. Broilers that received 100% organic feed reached a lower body weight and grew slower than broilers that received 95% organic feed, caused mainly by a lower feed intake. 5. Broilers that received 95 or 100% organic feed had a higher incidence of breast blisters than broilers that received 80% organic feed. 6. The cost price for meat from broilers that received 80% organic feed was € 1.83 per kg live weight. The cost prices for broilers that received 95 and 100% organic feed were € 1.84 (+0.8%) and € 1.93 (+5.4%) per kg live weight respectively. 7. In conclusion, 95% organic feed led to a better performance than 100% organic feed in this study. Probably, the lower methionine content in the 100% organic feed negatively affected performance. The results for 95% organic feed were similar to 80% organic feed, except for a higher incidence of breast blisters.

The detection of quantitative trait loci (QTL) of behavioural traits has mainly been focussed on mouse and rat. With the rapid development of molecular genetics and the statistical tools, QTL mapping for behavioural traits in farm animals is developing. In chicken, a total of 30 QTL involved in pecking-related traits, open-field behaviour, tonic immobility, response to novel objects, and response to a restraint test were detected in different studies. In the search for a useful early predictor for feather pecking (FP) behaviour in adult laying hens, the following was found: FP in young animals is not a predictor for FP in adult animals, however, open-field behaviour in young animals is genetically correlated with FP in adult hens. Before the implementation of FP behaviour or open-field behaviour in breeding programmes, it is essential to know more about the correlation between these behavioural traits and also their relationship with production traits. Nevertheless, with the QTL for behavioural traits and the chicken genome sequence in progress, a better understanding of the underlying genetic mechanisms of behavioural traits will be feasible.