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This study was designed to evaluate the effects of green light emitting diode (LED) light during incubation and dietary organic macro and trace minerals during rearing on tibia morphological, biophysical, and mechanical characteristics of broiler chickens at slaughter age. The experiment was setup as a 2 × 2 × 2 factorial arrangement, with the following treatments: 1) light during incubation (green LED light or darkness), 2) macro mineral source during rearing (organic or inorganic Ca and P), and 3) trace mineral source during rearing (organic or inorganic Fe, Cu, Mn, Zn, and Se). A total of 2,400 eggs (Ross 308) were either incubated under green LED light (16L:8D) or in complete darkness. After hatch, a total of 864 male broiler chickens were reared until slaughter age (day 42) and provided with 1 of 4 diets, differing in macro and/or trace mineral source. During rearing, the experiment had a complete randomized block design with 9 replicate pens per treatment and 12 chickens per pen. At slaughter age (day 42), 2 chickens per replicate were randomly selected and tibia bones were obtained. Tibia weight, length, thickness, osseous volume, pore volume, total volume, mineral content, mineral density, ultimate strength, and stiffness were determined. Green LED light during incubation did not affect any of the tibia characteristics. Dietary organic macro minerals positively affected most of the tibia morphological, biophysical, and mechanical characteristics compared to the inorganic macro minerals, whereas trace mineral sources did not affect tibia characteristics. It can be concluded that dietary organic macro minerals Ca and P stimulated tibia characteristics, whereas green LED light during incubation and dietary trace minerals during rearing did not affect tibia characteristics, locomotion, or leg disorders.

Pen enrichment for broiler (meat-type) chickens is one of the potential strategies to stimulate locomotion and consequently contribute to leg health and welfare. This study was designed to evaluate effects of using a plethora of pen enrichments (barrier perches, angular ramps, horizontal platforms, large distance between feed and water and providing live Black Soldier fly larvae in a dustbathing area) on tibia characteristics, locomotion, leg health and home pen behaviour of fast and slower-growing broiler chickens. The experiment was set up as a 2 x 2 factorial arrangement with a total of 840 male broiler chickens in a complete randomized design (7 replicates per treatment and 30 chickens per replicate) with the following treatments: 1) pen enrichment (enriched pen or non-enriched pen); 2) broiler strain (fast-growing Ross 308 or slower-growing Hubbard JA 757). Home pen behaviour and use of enrichment were observed. At approximately 1400 and 2200 gram body weight, two chickens per pen were randomly selected and slaughtered, to investigate tibia morphological, biophysical and mechanical characteristics and leg health. Pen enrichment positively affected tibia biophysical characteristics, e.g., osseous volume (Δ=1.8 cm3, P=0.003), total volume (Δ=1.4 cm3, P=0.03) and volume fraction (Δ=0.02 %, P=0.002), in both fast and slower-growing chickens, suggesting that pen enrichment particularly affects ossification and mineralization mechanisms. Accordingly, locomotion and active behaviours were positively influenced by pen enrichment. However, pen enrichment resulted in lower body weight gain in both strains, which might be due to higher activity or lower feed intake as a result of difficulties of crossing the barrier perches. Regarding the strain, slower-growing chickens showed consistently more advanced tibia characteristics and more active behaviour than fast-growing chickens. It can be concluded that pen enrichment may lead to more activity and better bone development in both fast and slower-growing chickens.

In the Netherlands, the production of broiler chickens experienced a significant change between 2014 and 2016 due to alternative production concepts being introduced, i.e. the slower-growing concept. Currently, around 35-40% of broiler chickens is produced in the Netherlands according to this slower-growing concept. However, because the slower growing breeds have only recently been introduced, we lack knowledge with regard to the environmental enrichments that are needed to meet their behavioural needs. This pilot study was performed within the PPP Slower growing broiler chickens (SloGro/SloBro) and aimed to identify the preference of slower-growing broilers for different types of rest (round metal perch, mushroom plastic perch, flat-shape plastic perch, round wooden perch and platform) and activity enrichment (firmly pressed straw bale (control, current standard), loosely pressed straw bale and lucerne bale). The number of birds sitting on the platforms was 8 times higher as compared to the perch types combined. When looking at the number of birds sitting under the different types of rest enrichments, birds seemed to have a slight preference to sit under the round metal perch, while the round wooden perch was least preferred. The number of birds sitting on the loosely pressed straw bales was higher compared to the number of birds on the firmly pressed straw and lucerne bales. This might be related to less birds sitting around the loosely pressed straw bales and therefore less disturbance compared to the firmly pressed straw and lucerne bales. To conclude, slower-growing broilers preferred platforms over perches. With regard to activity enrichments, slower-growing broilers seemed to prefer to sit on loosely pressed straw bales, while they seemed to prefer to sit around firmly pressed straw and lucerne bales.

The aim of this study was to explore lameness and the associations between lameness and health/production measures of animal welfare in commercial broiler production, using the Welfare Quality ® protocol for broilers. A total of 50 flocks were included in the sample and farm visits were conducted for lameness scoring at a mean age of 28.9 days. The percentage of animals (n=7500) in the six different gait score (GS) categories were GS0: 2.53%, GS1: 44.19%, GS2: 33.84%, GS3: 16.32%, GS4: 2.36% and GS5: 0.53%. Production and other welfare data were collected for each flock after slaughter. Higher gait scores were associated with increased hock burn score (P

On-farm hatching systems for broiler chicks are increasingly used in practice. We studied whether or not performance, health and welfare aspects differed between commercial flocks hatched on-farm or in a hatchery (control). In two successive production cycles on seven farms, a total of 16 on-farm hatched flocks were paired to 16 control flocks, housed at the same farm. Paired flocks originated from the same batch of eggs and were subjected to similar on-farm management. On-farm hatched and control flocks only differed with respect to hatching conditions, with on-farm hatched flocks not being exposed to, for example, chick handling, post-hatch feed and water deprivation and transport, in contrast to control flocks that were subjected to standard hatchery procedures, subsequently transported and placed in the poultry house. Day-old chick quality (navel and hock scores), 1st week mortality, total mortality, BW at day (d) 0, d7 and at depopulation, and (total) feed conversion ratio were determined. Prevalence of footpad dermatitis, hock burn, breast discoloration/blisters and cleanliness, litter quality and gait score were determined at d21 of age and around depopulation (d39 on average). Gross pathology and gut morphology were examined at depopulation age in a sample of birds of five flocks per treatment. On-farm hatching resulted in a higher BW at d0 (Δ=5.4 g) and d7 (Δ=11.5 g) (Plt;0.001), but day-old chick quality as measured by navel (P=0.003) and hock (P=0.01) quality was worse for on-farm hatched compared to control birds. Body weight, 1st week and total mortality, and feed conversion ratio at slaughter age were similar for both on-farm hatched and control flocks. On-farm hatched flocks had less footpad dermatitis (P=0.05), which indicated a better welfare. This was likely related to a tendency for better litter quality in on-farm hatched flocks at 21 days of age in comparison to control flocks (P=0.08). No major differences in gross pathology or in intestinal morphology at depopulation age were found between treatments. In conclusion, on-farm hatching resulted in better 1st week broiler performance and better welfare compared to conventional hatching in a hatchery.

More than 60 billion of broilers are reared and slaughtered for meat production yearly. The majority of broilers worldwide is housed indoors in floor systems and is of a fast-growing breed. Welfare problems have been associated with their efficient growth, the rearing environment and flock management. Examples are impaired leg health and behavioural restriction (the inability to perform their species-specific behaviour). Breed (fast- or slow-growing), hatching environment, stocking density, light, litter, air quality and environmental enrichment all affect broiler welfare, although their interactive effects are often unclear. Prevalence of welfare problems is generally lower in ‘higher-welfare’ systems, involving a slower growing broiler strain, lower stocking density and environmental enrichment. There seems to be a trend towards implementation of these higher-welfare systems in Europe and the US, although there is currently little information on needs and preferences of slower-growing strains and welfare of broilers in different production systems.

The results of a literature study to the effect of different types of environmental enrichment and light conditions on broiler chickens welfare are described, in order to attempt to provide an environment to slow-growing broiler chickens that better meets their behavioural requirements. With respect to environmental enrichment, a review paper has been used as a starting point and more recent information has been collected and summarised. With respect to lighting, in consultation with stakeholders we chose to limit the literature study to a fewpotential interesting areas of research (e.g. natural light provisionand its variation across the broiler house). There are several research questions in relation to enrichment provision, e.g., optimal perch design, multiple use of enrichments and the actual number of enrichments that should be provided. Currently, little is known about the need for light in slow-growing broiler chickens and how this interacts with the environmental enrichment offered. Future research priorities include theoptimization of methods of natural light provision (which is often applied in higher welfare indoor systems with slow-growing breeds), testing effects of ultraviolet wavelengths on chicken behaviour,and light colour preferences in slow-growing breeds.

Nutrition is a crucial factor for growth and bone development in broiler chickens. Adjustments in dietary ingredients might affect bone development and consequently locomotion related problems. This study was designed to evaluate effects of dietary organic minerals (ORM), fish oil (FISH), and hydrolyzed collagen (COL) on growth performance and tibia characteristics of broiler chickens. A total of three hundred eighty four 1-day-old Ross 308 male broiler chickens were used in a complete randomized block design with 4 diet groups and 8 replicates per diet group. In the ORM diet, the inorganic macro and trace minerals were replaced by their organic varieties. In the FISH diet, palm oil and soybean oil were partly replaced by FISH. In the COL diet, soybean meal was partly replaced by COL. Results showed that the ORM and COL diet groups reached a higher body weight (BW) at 42 D of age than the FISH diet group, whereas the control group was in between. The feed conversion ratio between day 1 and 42 was lower in the ORM and COL diet groups than in both other diet groups. On day 28, 35, and 42, gait score (GS), Varus Valgus deformity, tibia length (TL), thickness, femoral and metatarsal head thickness (THT), mineral content (TMC), mineral density (TMD), breaking strength (TBS), stiffness (TSF), and energy to fracture (TEF) were measured (n = 3/replicate). The ORM diet group had higher TL at day 42, higher THT at day 28, higher TMC at day 42, higher TMD at day 28, 35, and 42, higher TBS at day 42, higher TSF at day 35 and 42, and higher TEF at day 42 compared to the FISH diet group, with the COL and control diet groups in between. It can be concluded that replacing dietary inorganic macro and trace minerals by their organic varieties seems to stimulate tibia dimensions, strength, and mineral content of broiler chickens. On the contrary, FISH appears to negatively affect tibia characteristics.

The current report describes the development of the ‘animal welfare dimension’ (‘welfare assessment model’) within the overall Greenwell sustainability model. As we apply the framework of Welfare Quality®, in which animal health is considered one of the aspects of animal welfare, the model also includes health indicators. The model has been developed according to two steps: definition of long-lists of indicators for the broiler breeder, hatchery, broiler on-farm and broiler end-of-life stage, and the selection of key indicators from these long-lists, as well as whether these need to be measured real-time or can be estimated by a representative sample or literature value. Dit rapport beschrijft de ontwikkeling van de dimensie ‘dierenwelzijn’ binnen het Greenwell duurzaamheid beoordelingsinstrument (ook wel ‘welzijnsmodel’ genoemd). Omdat het raamwerk van Welfare Quality® wordt toegepast, waarbinnen diergezondheid wordt beschouwd als onderdeel van dierenwelzijn, bevat het welzijnsmodel ook diergezondheidsindicatoren. Het model is in twee stappen ontwikkeld: eerst volledige lijsten van mogelijke indicatoren voor de ouderdierenfase, broederijfase, vleeskuikenfase primair bedrijf en vleeskuikenfase wat betreft vangen/transport/slachten, en vervolgens de selectie van de belangrijkste indicatoren uit deze lijst. Daarbij wordt tevens aangegeven of de indicatoren continu gemonitord moeten worden of dat een inschatting op basis van de literatuur of een steekproef kan volstaan.

The European Union (EU) Broiler Directive (2007/43/EC) is unique amongst current EU Directives, which address animal welfare, in that it uses outcome data collected at abattoirs and on farm to monitor on-farm broiler welfare and vary the maximum permitted stocking density on farm. In this study, we describe how, by bringing together personnel from the competent authorities in 22 member states (MSs) who have responsibility for implementing the Directive, and engaging in exchange of information and technical methods regarding the Broiler Directive, it has been possible to identify differences in approach with regard to ‘what data is being collected, and by whom’ across EU MSs. Online questionnaires and workshop exercises enabled us to identify priority areas for knowledge transfer and training. For example, foot pad dermatitis, hock burn, dead on arrival and total rejections (birds rejected as unfit for human consumption by the meat inspection staff at slaughter) were identified by the MSs as measures of medium-to-low priority in terms of knowledge transfer because there are assessment methods for these conditions that are already well accepted by competent authorities. On the other hand, breast lesions, cellulitis, emaciation, joint lesions, respiratory problems, scratches, wing fractures and a number of environmental measures were identified as having high priority in terms of knowledge transfer. The study identified that there is significant variability in the stage of implementation between MSs, and responses from the participating MSs indicated that sharing of guidance and technical information between MSs may be of value in the future set-up process for those MSs engaged in implementation of the Directive.

Welfare problems are commonly found in both conventional and organic production of broiler chickens. In order to reduce the extent of welfare problems, it has been suggested to provide stimulating, enriched environments. The aim of the present paper is to provide a review of the effect on behavior and welfare of the different kinds of environmental enrichments in the production of broilers that have been described in the scientific literature. Environmental enrichment is defined as an improvement of the environment of captive animals, which increases the behavioral opportunities of the animal and leads to improvements of the biological function. This definition has been broadened to include practical and economic aspects, as any enrichment strategy that adversely affects the health of animals or that has too many economic or practical constraints will never be implemented on commercial farms and thus never benefit animals. Environmental enrichment for broilers often has the purpose of satisfying behavioral needs and/or stimulating the broilers to an increased level of activity, which among others will reduce the occurrence of leg problems. Potentially successful environmental enrichments for broiler chickens are elevated resting-places, panels, barriers, and bales of straw ("point-source enrichment"), as well as covered verandas and outdoor ranges ("complex enriched environments"). Many of the ideas for environmental enrichment for broilers need to be further developed and studied, preferably in commercial trials, with respect to the use, the effect on behavior and on other welfare aspects such as leg health, and the interaction with genotype, production system, stocking density, light, and flock size. In addition, information on the practical application and the economics of the production system is often lacking, although it is important for application in practice.

In the Welfare Quality® assessment protocol for broilers, the touch test is included to assess the human–animal relationship in the flock. The test is designed to measure the animals’ fear of humans, assuming that broilers will withdraw from the observer if they are fearful. However, many broilers close to slaughter age have impaired walking ability, and the results from the touch test may thus be biased by lameness and poor leg health. As the touch test is currently being used in several countries to assess human–animal relationship in broilers, there is an urgent need to examine this potential relationship for a further validation of the test. In the present study, fear of humans was assessed in 50 randomly selected Norwegian broiler flocks, using the touch test as described in the Welfare Quality® protocol for ty broilers. Leg health was assessed by examining the gait of 150 random birds in each of the flocks, using a six-point gait score scale from 0 to 5. The coefficient for the relationship between touch test score and gait score was 0.034 (P

To ensure health and reproductive performance, broiler breeders are feed restricted during the rearing period and, to a lesser extent, during the production period. Although restricted feeding improves health and bird welfare, on the other hand the birds are chronically hungry and suffer from frustration of feeding motivation, which has a negative effect on bird welfare. The aim of the current paper is to give an overview of the role of feed (nutritional aspects as well as feeding management) as a possible tool to improve broiler breeder welfare. Possible strategies discussed are 1) dietary dilution, by reducing the energy content and/or increasing the NSP content, by adding soluble or insoluble fibres to the diet; 2) adding appetite suppressants (e.g. calcium propionate) to the diet; 3) changing feeding management (e.g., scattering feed in the litter). Some of these strategies, i.e. dietary dilution or adding appetite suppressants, positively affect behavioural patterns of the birds, by reducing stereotypic pecking and eating motivation, and increasing the time spent sitting. Appetite suppressants have however been criticised for causing birds to feel ill. These behavioural changes, however, can only be considered as indirect parameters of improved bird welfare and there is still a need for a reliable indicator of hunger. It is clear that nutritional strategies can be helpful in reducing hunger stress in broiler breeders. Nutrition, however, cannot fully solve the broiler breeder paradox. The main reason for this paradox is related to breeding goals that are focussed on improving feed conversion and increasing breast meat percentage. Future genetic selection should aim at uncoupling the link between (re)production and welfare or reducing the conflict between these outcomes.

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

In The Netherlands, laying hen chicks are often reared without litter on the raised slatted area of a barn system or confined in the aviary system during the first two to five weeks after hatching, with chick paper or chicken wire on the floor. In the absence of a suitable pecking substrate, chicks may redirect their pecking behaviour to other birds, which possibly increases the risk of developing feather-pecking behaviour. The aim of this study was to determine whether housing on wood-shavings (WS treatment; n = 15 groups) as compared to housing on chicken wire (CW treatment; n = 15 groups) between day 1-20 could reduce feather pecking in adult birds. After day 20, all chickens were allowed wood-shavings as litter. Behavioural observations showed that CW chicks performed significantly less ground-pecking behaviour compared with WS chicks up to day 20. More CW chicks showed gentle feather pecking at day 7 and 14 as compared to WS chicks, and more CW chicks pecked at the feeder or drinker than WS chicks up to day 20. CW chicks showed rebound behaviour: the day after they were introduced to wood-shavings they displayed more ground-pecking behaviour compared to the WS chicks. Later on in the rearing period no noticeable differences between treatments were found in frequency of gentle and severe feather-pecking bouts. During laying, more gentle feather-pecking bouts were observed in CW than in WS groups but no differences in severe feather-pecking bouts were observed, nor in feather damage at the end of the trial. The results indicate that hens can display substantial flexibility in their pecking behaviour and that, despite more gentle feather pecking in CW hens in laying, the absence of substrate in early rearing does not increase the risk of developing severe feather-pecking behaviour when adult.

The current report describes the results of a validation of the Meyn Footpad Inspection System, a video imaging system to score footpad lesions in broiler chickens at the slaughter plant. It was suggested that the system might assign a different score to footpad lesions compared to a trained manual scorer. Therefore, on the request of the Ministry of Economic Affairs, Wageningen Livestock Research performed a limited validation of the system during two days at a commercial plant in The Netherlands. During the validation, the footpad lesion score was determined in a sample of each flock slaughtered on that particular day, manually by a trained observer as well as by the camera system, and the results were compared. This reports describes the results of this validation. Dit rapport beschrijft de resultaten van een validatie van het Meyn Footpad Inspection System, een camerasysteem om automatisch voetzoollaesies bij vleeskuikens aan de slachtlijn te beoordelen. Er gaan geluiden op dat dit camerasysteem mogelijk anders scoort dan handmatige metingen aan de slachtlijn door getrainde slachterijmedewerkers. Op verzoek van het Ministerie van Economische Zaken heeft Wageningen Livestock Research daarom een beperkte validatie van het camerasysteem uitgevoerd. Deze validatie werd uitgevoerd op één Nederlandse slachterij en omvatte twee reguliere slachtdagen. Op deze slachtdagen werd de voetzoollaesiescore van een steekproef van alle aangevoerde koppels zowel handmatig als met de camera bepaald. In dit rapport worden de resultaten van deze metingen beschreven.

The current report describes the results of a validation of the Meyn Footpad Inspection System, avideo imaging system to score footpad lesions in broiler chickens at the slaughter plant. It wassuggested that the system might assign a different score to footpad lesions compared to a trainedmanual scorer. Therefore, on the request of the Ministry of Economic Affairs, Wageningen LivestockResearch performed a limited validation of the system during two days at a commercial plant in TheNetherlands. During the validation, the footpad lesion score was determined in a sample of each flockslaughtered on that particular day, manually by a trained observer as well as by the camera system,and the results were compared. This reports describes the results of this validation. Dit rapport beschrijft de resultaten van een validatie van het Meyn Footpad Inspection System, eencamerasysteem om automatisch voetzoollaesies bij vleeskuikens aan de slachtlijn te beoordelen. Ergaan geluiden op dat dit camerasysteem mogelijk anders scoort dan handmatige metingen aan deslachtlijn door getrainde slachterijmedewerkers. Op verzoek van het Ministerie van EconomischeZaken heeft Wageningen Livestock Research daarom een beperkte validatie van het camerasysteemuitgevoerd. Deze validatie werd uitgevoerd op één Nederlandse slachterij en omvatte twee reguliereslachtdagen. Op deze slachtdagen werd de voetzoollaesiescore van een steekproef van alleaangevoerde koppels zowel handmatig als met de camera bepaald. In dit rapport worden deresultaten van deze metingen beschreven.

This chapter discusses the management of broiler breeders, that is, the parent stock of broiler chickens, and welfare issues related to the different life stages of broiler breeders. Where commercial broilers are the product of a cross of four lines, broiler parent stock (broiler breeders) are the product of a cross of two lines; both the male and female broiler breeder is the product of a cross of a specific paternal line and a specific maternal line (Hiemstra and Ten Napel, 2013). The actual figures on the number of broiler breeders worldwide are lacking; as an indication, in Europe the number of broiler breeders is estimated to be 44 million (Horne and Bondt, 2014). Management and housing of grandparents and great grandparents (but not pedigree stock) is to a large extent similar to that of broiler breeders (EFSA, 2010; Hiemstra and Ten Napel, 2013) and not described in this chapter. Nowadays, three companies dominate the world market for broiler breeding stock: Aviagen Broiler Breeders, Cobb-Vantress and Hubbard. The majority of the broiler breeders worldwide are the parent stock of the so-called standard or fast growing broilers, which reach a body weight of 2.5 kg in 42 days or ess (EFSA, 2010). Dwarf parental females are used to produce broilers of intermediate (2.2 kg in 56–63 days of age) or slow growth rate (2.2 kg in 70–80 days of age) (De Jong and Swalander, 2013). Although worldwide only a small percentage of parent stock for intermediate or slow growing broilers is housed, in some countries a larger proportion of the total number of broiler breeders produce intermediate or slower growing broiler strains. For example, in France, the majority of the parent stock –85% according to De Jong and Guemene (2011) – are parents of intermediate or slower growing broiler strains (EFSA, 2010). In Europe, about 8% of the broiler breeders are estimated to be parent stock of intermediate or slower growing broilers (Horne and Bondt, 2014). We provide a short, general description of housing and management of broiler breeders during both the rearing and the production period in the next paragraph. In addition, we focus on (major) welfare issues related to the management of broiler breeders and the current state-of-the-art research related to these welfare issues.

The introduction of the UK Protection of Animals Act 1911 demonstrates that animal welfare has been of concern for at least a century. The matter came to the fore about 50 years ago, when the welfare of hens in battery cages became an issue. Since then poultry welfare research and the development of superior management and housing systems for poultry have been stimulated by the lobbying of animal welfare organisations along with subsequent policy decisions and legislation. WPSA WG9 was formed in 1972 to encourage scientific studies to inform the poultry welfare debate; its members have positively influenced research and development of welfare-friendly housing systems and husbandry throughout Europe. They have also been active in EU projects aimed at improving the wellbeing of poultry e.g. LayWel, EFSA Opinions and Welfare Quality®. Information derived from such projects has influenced EU Directives and national legislation on the protection and welfare of laying hens and broilers, in particular.

For monitoring purposes there is a need for a protocol to measure foot-pad dermatitis (FPD) on-farm. Therefore, we studied the effect of number of birds sampled, number of locations sampled and sampling location in a broiler house on the accuracy of measurement, in order to construct a protocol that can be applied in practice. Samples were taken from eight commercial flocks (Ross 308) at up to ten locations with up to 25 birds sampled per location. Foot-pad lesions were scored in all birds for both feet using the Swedish scoring method. No significant differences in FPD score were found between the first five birds and all birds sampled at a particular location. Although locations near the walls did not differ in FPD score from locations in the central area of a house, the severity of foot-pad lesions was unevenly distributed over the house. A model was constructed showing the inaccuracy related to the number of locations sampled in the house and the number of birds sampled per location. The model shows that in situations with at least five locations differences in inaccuracy are relatively small when a total of 100 birds or more is sampled. Inaccuracy is largest in a flock with variation in foot-pad scores, as compared to flocks with little variation. The results of this experiment can be used to determine the optimal sample size in a commercial broiler house.

International audience; Under current practices, broiler parent stock (broiler breeders) encounter several welfare problems, such as feed restriction and injury during mating. Intensive selection for production traits, especially growth rate, is associated with increased nutritious requirement and thus feed consumption, but also reproductive dysfunctions and decreased sexual activity in broiler breeders. A resulting serious welfare problem is the subsequent severe feed restriction which is applied during rearing, in order to prevent health problems and to achieve better egg production. This severe feed restriction has negative effects on bird welfare as it causes chronic stress resulting from hunger. Recent research has focused on management practices to alleviate the negative effect of this feed restriction. Using both a more fibrous feed and an appetite suppressant seems most successful. There are welfare concerns involved in the mating of broiler breeders. In many countries mutilations (beak trimming, despurring and toe clipping) are carried out in male broiler breeders as a standard procedure to prevent excessive damage to the hens during mating. It has been reported that broiler breeder males show low libido but, at the same time, may be aggressive and show rough behaviour during mating, which can cause severe injuries to the hens, although some injuries may be caused by over-mating hens. Current studies aim to develop management practices to reduce hen injury due to over-mating and improve the sexual behaviour in both males and females. In the last part of the review, an examination of how breeding companies are taking welfare into consideration in their commercial selection scheme is made. In practice, although for example reduced mortality and some health criteria are included in selection programs and some alternative breeds as used, other welfare issues remain, such as feed restriction during rearing.

Low-density diets may improve welfare of restricted fed broiler breeders by increasing feed intake time with less frustration of feed intake behavior as a result. Moreover, low-density diets may promote satiety through a more filled gastrointestinal tract, and thus feelings of hunger may be reduced. Broiler breeders were fed 4 different diets during the rearing and laying periods. Behavioral and physiological parameters were measured at different ages as indicators of hunger and frustration of the feeding motivation. A diet of 8.4 MJ/kg as compared with a standard diet of 10.9 MJ/kg extended feeding time and reduced stereotypic object pecking at 6 and 10 wk of age. Furthermore, compensatory feed intake at 12 wk of age was reduced. During lay, differences in behavior were observed between the treatments that could be attributed to differences in feeding time. However, birds fed the diet with the lowest energy content (i.e., 9.2 MJ/kg) had higher heterophil to lymphocyte ratios (H/L) at 40 wk of age compared with the other treatments, indicating that they experienced more stress during the laying period than the other treatments. This result could have been due to the very long feeding time of this treatment group during lay, which may be stressful. In conclusion, a low-density diet of 8.4 MJ/kg may reduce hunger and frustration in the first half of the rearing period. However, for substantial improvement of broiler breeder welfare during rearing, more extreme diet modifications are required.

1. In previous studies, a lack of agreement in measurements of plasma corticosterone concentrations and heterophil:lymphocyte (H/L) ratio as physiological indices of stress, caused by hunger and frustration in restricted-fed broiler breeders, was observed. It could be suggested that the differences between previous studies were caused by differences in duration of restriction and time of the day of the measurements. Therefore, in the present study the plasma corticosterone concentration and the H/L ratio were again determined in restricted- and ad libitum-fed growing broiler breeders, taking possible causes of disagreement between previous studies into account. In addition, we measured the daily rhythm in body temperature and heart rate, and the corticosterone responses to an acute stressor as physiological indices of stress. 2. Female broiler breeders (64 per treatment, housed in groups of 4 birds) were used in the experiment. Behaviour, baseline plasma corticosterone concentrations and H/L ratio were determined at 21 d of age (immediately after the start of food restriction), and at 42 and 63 d of age. Body temperature, heart rate and activity were measured by radiotelemetry for 36 h at 49 and 70 d of age. In addition, the plasma corticosterone response to acute stress (5 min manual restraint) was measured at 77 or 78 d of age. 3. Restricted broiler breeders had higher plasma corticosterone concentrations at 42 and 63 d of age, but no differences in H/L. ratio were found between restricted birds and unrestricted control birds. Restricted broiler breeders had a higher corticosterone response to 5 min manual restraint than unrestricted birds. Restricted birds displayed a clear day-night rhythm in body temperature, heart rate and activity whereas such a rhythm was blunted in ad libitum-fed birds. 4. It is discussed that some physiological differences (plasma corticosterone concentrations, body temperature and heart rate) between ad libitum-fed and restricted broiler breeders may have been caused by differences in metabolic rate as well as by differences in the level of stress. It is concluded that a combination of behavioural measurements and a wide range of physiological parameters should be used for the assessment of stress in growing broiler breeders.

The physiological and behavioural responses of slaughter pigs reared in either a barren environment or in an enriched environment (larger pens with straw bedding) to preslaughter handling and mixing at transport were studied. Enriched-reared pigs had higher salivary cortisol concentrations in the home pen before and after transport than barren housed pigs, but at the end of the lairage period salivary cortisol concentrations did not differ between enriched- and barren-housed pigs. In pigs reared in a barren environment, salivary cortisol concentrations increased significantly after transport and being in lairage, as compared to home pen salivary cortisol concentrations. In pigs reared in an enriched environment, salivary cortisol concentrations did not significantly change after any stage of preslaughter handling and transport as compared with home pen salivary cortisol concentrations. In the truck, pigs reared in a barren environment tended to spend more time walking, standing and manipulating other pigs than enriched-reared pigs. Moreover, pigs reared in a barren environment tended to spend more time walking and fighting in lairage than enriched-reared pigs. Results showed that rearing conditions may affect the behavioural and physiological responses of pigs to preslaughter handling and mixing at transport. The tendency for increased manipulation of pen mates and fighting, and the significant increases in salivary cortisol in response to mixing at transport and being in lairage in pigs reared in a barren environment indicate that pigs reared in a barren environment are likely to experience more stress during common preslaughter procedures than pigs reared in an enriched environment. Key words: Behaviour, cortisol, housing conditions, pigs, slaughter

Previously we showed that pigs reared in an enriched environment had higher baseline salivary cortisol concentrations during the light period than pigs reared under barren conditions. In the present experiment, it was investigated whether these higher baseline salivary cortisol concentrations were a real difference in cortisol concentration or merely represented a phase difference in circadian rhythm. The effects of different cortisol concentrations on the behavioral responses to novelty and learning and long-term memory in a maze test were also studied in enriched and barren housed pigs. At 9 weeks of age enriched and barren housed pigs did not differ in baseline salivary cortisol concentrations nor in circadian rhythm, but at 22 weeks of age barren housed pigs had a blunted circadian rhythm in salivary cortisol as compared to enriched housed pigs. The differences in baseline salivary cortisol concentrations between enriched- and barren-housed pigs are age-dependent, and become visible after 15 weeks of age. Enriched- and barren-housed piglets did not differ in time spent on exploration in the novel environment test. Barren-housed pigs had an impaired long-term memory in the maze test compared to enriched-housed pigs; however, no differences in learning abilities between enriched- and barren-housed pigs were found. Because blunted circadian cortisol rhythms are often recorded during states of chronic stress in pigs and rats or during depression in humans, it is suggested that the blunted circadian rhythm in cortisol in barren-housed pigs similarily may reflect decreased welfare. (C) 2000 Elsevier Science Inc. All rights reserved.

This paper summarizes the current views on coping styles as a useful concept in understanding individual adaptive capacity and vulnerability to stress-related disease. Studies in feral populations indicate the existence of a proactive and a reactive coping style. These coping styles seem to play a role in the population ecology of the species. Despite domestication, genetic selection and inbreeding, the same coping styles can, to some extent, also be observed in laboratory and farm animals. Coping styles are characterized by consistent behavioral and neuroendocrine characteristics, some of which seem to be causally linked to each ether. Evidence is accumulating that the two coping styles might explain a differential vulnerability to stress mediated disease due to the differential adaptive value of the two coping styles and the accompanying neuroendocrine differentiation. (C) 1999 Elsevier Science Ltd. All rights reserved.

The effects of housing conditions on behavioural and cortisol responses during preslaughter treatment, as well as the consequences for meat quality, were studied in 48 slaughter pigs. Pigs were either raised in intensive housing conditions ("standard" treatment: standard farrowing crates (4.2 m2) followed by standard rearing pens (0.5 m2/pig) and fattening pens (0.8 m2/pig) or in extensive conditions ("enriched" treatment: larger farrowing pens (7.2 m2) followed by larger rearing and fattening pens (both 1.2 m2/pig), all provided with straw).No differences in behaviour during transport or in any of the meat quality variables were found between treatments. During pre-slaughter handling, stockmen needed significantly less time to load pigs from standard housing conditions (standard: 56.8 ± 11.9 s; enriched: 93.7 ± 12.5 s). Standard pigs may have been more motivated to leave their pens in order to explore another environment than pigs from the enriched housing pens. Rise in salivary cortisol levels due to transport (standard: 6.68 ± 0.80 ng mL−1; enriched: 3.63 ± 0.58 ng mL−1) was difficult to interpret as omission of straw during the hours prior to transport apparently led to high baseline cortisol levels in enriched pigs (8.63 ± 1.27 ng mL−1 vs. 2.60 ± 0.37 ng mL−1 in standard pigs). The extensive housing system should be preferred as it is known to have positive effects on pig welfare, and does not lead to impaired meat quality. Key words: Behaviour, housing, meat quality, physiology, pigs, slaughter

The objectives of this study were to 1) identify determinants of poor welfare in commercial broiler chicken flocks by studying the associations between selected resource-based measures (RBM, potential risk factors), such as litter quality and dark period, and animal-based welfare indicators (ABM), such as foot pad dermatitis and lameness, and 2) establish the breadth of effect of a risk factor by determining the range of animal welfare indicators associated with each of the risk factors (i.e., the number of ABM related to a specific RBM). Eighty-nine broiler flocks were inspected in 4 European countries (France, Italy, the United Kingdom, and the Netherlands) in a cross-sectional study. The ABM were contact dermatitis (measured using scores of foot-pad dermatitis and hock burn, respectively), lameness (measured as gait score), fear of humans (measured by the avoidance distance test and the touch test), and negative emotional state (measured using qualitative behavior assessment, QBA). In a first step, risk factors were identified by building a multiple linear regression model for each ABM. Litter quality was identified as a risk factor for contact dermatitis. Length of dark period at 3 wk old (DARK3) was a risk factor for the touch test result. DARK3 and flock age were risk factors for lameness, and the number of different stockmen and DARK3 were risk factors for QBA results. Next, the ABM were grouped according to risk factor and counted. Then, in a second step, associations between the ABM were investigated using common factor analysis. The breadth of a risk factor's effect was judged by combining the number (count) of ABM related to this factor and the strength of association between these ABM. Flock age and DARK3 appeared to affect several weakly correlated ABM, thus indicating a broad range of effects. Our findings suggest that manipulation of the predominant risk factors identified in this study (DARK3, litter quality, and slaughter age) could generate improvements in the related ABM and thereby enhance the birds' overall welfare status.

This part updates the underlying report: The welfare of chickens kept for meat production (2000, available at http://ec.europa.eu/food/fs/sc/scah/out39_en.pdf).

This chapter describes the housing and management of broiler breeders and turkey breeders in Europe. The majority of broiler breeders in Europe are the standard, fast growing genotype, but 18-20% of the broiler breeders are dwarf parental females that produce standard and alternative (medium or slow growing) broilers. Broiler breeder housing systems are very similar in rearing and production; a low percentage of birds are in cages, and alternative systems are not used. Broiler breeders are generally housed in climate-controlled houses with litter floors during the rearing period and partially slatted floors during the production period. Males and females are reared separately until 18-21 weeks of age and then transferred to the production farm where they are housed together until 60-65 weeks of age. The restricted feeding regime during rearing is generally seen as one of the major welfare issues in broiler breeders as it leads to chronic hunger and frustration of the feeding motivation. The majority (>95%) of turkey breeders in Europe are of either heavy or heavy medium genotype with white plumage. The remainder of the turkey market consists of small strain white or coloured birds for whole bird seasonal production. Both conventional large strain turkeys and small strain traditional turkeys are used for outdoor/alternative production systems. Rearing of breeding turkeys is floor based on deep litter, and predominantly in environmentally controlled housing. Males and females are reared separately until 29 weeks of age and then transferred to laying facilities. Male parent stock is selected at 16-18 weeks paying attention to health, fitness, plumage and conformation. Laying facilities are either open-sided houses or controlled environment for breeder females, and typically controlled environment housing for breeder males. Breeding turkeys are kept in production until 56-60 weeks of age (i.e. 24-28 weeks lay). Quantitative feed restriction is applied in breeder males from selection age (16-18 weeks) to end of production, to maximize fitness and reproduction. Breeder females are fed unrestricted throughout rearing but on a lower-protein diet to avoid fatness of the hens. Injurious pecking is generally seen as the most important welfare issue in flocks where beak trimming is not applied.

In some European countries, footpad dermatitis (FPD) is measured as an indicator of broiler welfare. Prevalence and seasonal variation of FPD was determined within broiler flocks (fast-growing breeds) in the Netherlands. Samples were taken from 386 Dutch flocks at 8 slaughterhouses during a period of one year. Prevalence of footpad dermatitis was related to background information gathered using a food chain certification scheme to identify possible factors of influence. On average, 35.5% of the broilers had no lesions, whereas 26.1% and 38.4% had mild or severe lesions, respectively. Season, age, thinning of flocks, slaughter age, breed, slaughterhouse, and the interaction between thinning and slaughter age significantly affected severity of FPD. Peak flock FPD scores occurred in flocks where 1-d-old chicks were placed in March and December, whereas flocks placed in warm months, between June and August, displayed lower flock FPD scores. Generally, birds sent to slaughter when thinning a flock displayed less severe FPD than birds from completely depopulated flocks. Severity of FPD decreased with age. Because poultry farmer, hatchery, veterinary practice, and feed manufacturer were included in the model as random factors, it was only possible to assess their contribution relative to each other. The broiler farmer had the largest contribution. Also, a large contribution was found for hatchery, perhaps indicating that broiler quality is important. No relationship was observed between FPD and mortality. Across farms, less severe FPD was observed on farms using antibiotics. However, within farms, FPD was more common in flocks where antibiotics had been used compared with flocks that did not require antibiotic treatment. In conclusion, footpad dermatitis was frequently observed in Dutch fast-growing broiler flocks, and many factors had significant effects on severity of FPD, such as breed, thinning of flocks, age at slaughter, slaughter plant, and hatchery.

This chapter will mainly focus on the effects of feed restriction on the welfare of the broiler breeder chicken, where most of the research on feed restriction has been carried out. The effects of short- and long-term feed restriction and food deprivation on welfare in other types of domestic birds will also be discussed where relevant. In the first part of the chapter, the substantial literature on the effects of feed restriction or food deprivation on parameters indicative of domestic bird welfare will be reviewed. Thereafter, the merits and demerits of the various measures that can be applied to reduce the negative effects of feed restriction on broiler breeder welfare, while maintaining target body weight and (re)production at the required level, will be discussed.