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It is crucial to identify whether relations between immune characteristics and damaging behaviors in production animals exist, as these behaviors reduce animal welfare and productivity. Feather pecking (FP) is a damaging behavior in chickens, which involves hens pecking and pulling at feathers of conspecifics. To further identify relationships between the immune system and FP we characterized high FP (HFP) and low FP (LFP) selection lines with regard to nitric oxide (NO) production by monocytes, specific antibody (SpAb) titers, natural (auto)antibody (N(A)Ab) titers and immune cell subsets. NO production by monocytes was measured as indicator for innate pro-inflammatory immune functioning, SpAb titers were measured as part of the adaptive immune system and N(A)Ab titers were measured as they play an essential role in both innate and adaptive immunity. Immune cell subsets were measured to identify whether differences in immune characteristics were reflected by differences in the relative abundance of immune cell subsets. Divergent selection on FP affected NO production by monocytes, SpAb and N(A)Ab titers, but did not affect immune cell subsets. The HFP line showed higher NO production by monocytes and higher IgG N(A)Ab titers compared to the LFP line. Furthermore the HFP line tended to have lower IgM NAAb titers, but higher IgM and IgG SpAb titers compared to the LFP line. Thus, divergent selection on FP affects the innate and adaptive immune system, where the HFP line seems to have a more responsive immune system compared to the LFP line. Although causation cannot be established in the present study, it is clear that relationships between the immune system and FP exist. Therefore, it is important to take these relationships into account when selecting on behavioral or immunological traits.

Dual-purpose strains, with hens housed for egg laying and roosters kept for meat production are one alternative to the killing of male day-old chickens. However, dual-purpose hens seem to have additional advantages compared to conventional layers, for instance, a lower tendency to develop behavioral disorders, such as feather pecking and cannibalism. In the present study, three batches of about 1850 conventional layers (Lohmann Brown plus, LB+) and 1850 dual-purpose hens (Lohmann Dual, LD) each, all of them with untrimmed beaks, were observed during production (20&ndash, 71 (56) weeks of life) in a semi-commercial aviary system. The aim was to investigate whether the hybrid and batch affected the occurrence of injurious pecking, and to identify a detailed time course of the damage caused by this behavior. Therefore, the hens&rsquo, plumage and skin condition were assessed as an indicator by means of a visual scoring method. The LB+ hens had higher production performances and higher mortality rates compared to the LD hens. Plumage loss in the LB+ flocks started at 23 to 25 weeks of age, and deteriorated continuously. The LD hens showed only moderate feather loss on the head/neck region, which started at 34 to 41 weeks and remained almost constant until the end of the observations. Compared to feather loss, injuries occurred in the LB+ hens with a delay of several weeks, with a maximum of 8% to 12% of hens affected. In contrast, skin injuries were observed only sporadically in single LD hens. In all batches, hybrid had an effect on the occurrence of feather loss (p &lt, 0.05). Within the LB+ strain, the proportions of hens affected by plumage loss and injuries differed among batches (p &lt, 0.05), whereas this was not the case in the LD flocks. Thus, severe feather pecking and cannibalism seemed to occur in the conventional layer hybrids but not in the dual-purpose hens, though both genetic strains were raised and managed under the same semi-commercial conditions. Therefore, keeping dual-purpose hens should also be considered as an alternative approach to avoid injurious pecking in laying hen husbandry.

In on-farm hatching systems, eggs are transported at d 18 of incubation to the broiler farm, where chickens have immediate access to feed and water after hatching. In hatchery-fed systems, newly hatched chickens have immediate access to feed and water in the hatchery and are transported to the farm thereafter. Conventionally hatched chickens can remain without access to feed and water up to 72 h after hatching until placement on the farm. The current study compared day-old chicken quality, performance, and slaughter yield of broiler chickens that were on-farm hatched (OH), hatchery-fed (HF), or conventionally hatchery-hatched (HH). The experiment was performed in 6 rooms in 1 house. Each room contained 2 duplicate pens with approximately 1,155 chickens per pen; 2 rooms with each 2 duplicate pens were assigned to 1 treatment. The experiment was repeated during 3 consecutive production cycles. Chickens originated from young parent stock flocks. Results showed that HF and OH chickens were heavier and longer than HH chickens at day (D) 1. Relative weight of stomach and intestines were highest for OH chickens. The OH chickens had worse day-old chicken quality in terms of navel condition and red hocks than HH and HF chickens. Treatments did not differ in first wk and total mortality. From D0 until slaughter age, body weight was highest for OH, followed by HF and HH. Furthermore, carcass weight at slaughter age (D40) was highest for OH chickens, followed by HF and HH chickens. Breast fillets showed a higher incidence of white striping and wooden breast in HF and OH chickens compared with HH chickens. In conclusion, the current study showed that both OH and HF chickens of young parent flocks had better growth performance, which could explain the higher prevalence of breast myopathies, compared with HH. The worse day-old chicken quality for OH compared with HH and HF does not seem to affect first wk mortality and later life performance.

Broiler chicks usually hatch in the hatchery without access to feed and water until placement at the farm. This can affect their health and welfare negatively. Therefore, alternative strategies have been developed, for instance providing chicks with early nutrition in the hatchery or hatching eggs directly on-farm. However, information on the physical and mental welfare of chicks hatched in these systems compared to conventionally hatched chicks is limited. The aim of this study was to investigate the effects of alternative hatching systems on the welfare of broiler chickens in early and later life. A system comparison was performed with chickens that hatched conventionally in a hatchery (HH), in a system which provided light, feed, and water in a hatcher (hatchery-fed, HF), or on-farm (on-farm hatched, OH, where feed and water were available and transport of day-old chicks from the hatchery to the farm was not necessary). Chickens were reared in 3 batches, in 12 floor pens per batch (approximately 1,155 animals per pen), with a total of 12 replicates per treatment. Animal-based welfare indicators were assessed following standard protocols: plumage cleanliness, footpad dermatitis (FPD), hock burn, skin lesions (all at day 21 and 35 of age), and gait score (day 35). Furthermore, a set of behavioral tests was carried out: novel environment (day 1 and 21), tonic immobility, novel object, and avoidance distance test (day 4 and 35). Plumage cleanliness, hock burn, and skin lesions were affected by age but not by hatching system, with older broilers scoring worse than younger ones (P < 0.05). An effect of hatching system was only found for FPD, with the highest prevalence in HH chickens, followed by HF and OH chickens (P < 0.05). All responses measured in the behavioral tests were affected by age but not by hatching system. In later life, chickens were significantly less fearful than during the first days of life. The results indicate that conventionally hatched chickens scored significantly worse for FPD, whereas, in general, hatching system seemed to have minor effects on other broiler welfare indicators.

Information on the behavior of chickens hatched in different systems is limited and inconsistent across different studies. Changes in broiler activity can be measured automatically and continuously. The aim of this study was to assess the effects of 3 hatching systems on flock activity using a commercial tracking system, and to compare these findings to individual activity measured under experimental conditions. As this experiment was part of a larger study, it was possible to investigate the effects of vaccination on individual activity. In study 1, flock activity was measured in chickens that hatched either conventionally in the hatchery (HH), in a system which provided nutrition in the hatcher (HF), or on-farm (OH). Chickens were reared in 2 batches, in 12 pens/batch (1,155 animals/pen). One camera recorded top-view images of each pen. A daily activity index (moved pixels/total pixels × 100) was calculated by automated image analysis. In study 2, individual activity was measured under experimental conditions using an ultra-wideband (UWB) system. Chickens from the 3 hatching systems were reared in 3 pens (1 pen/treatment, 30 animals/pen). At d14, UWB-tags were attached to 5 chickens/pen, which tracked the distances moved (DM). In study 1, group level activity showed a significant age × hatching system interaction (F 8,752= 5.83, P < 0.001). HH and HF chickens showed higher activity levels than OH chickens in wk 1, 4, and 5. In wk 3, higher activity levels were measured in HH compared to HF, and in HF compared to OH pens. In contrast, HH chickens in small groups in study 2 showed lower DM than HF and OH chickens in wk 3 (P < 0.001). DM did not differ between treatments before vaccination, however, thereafter, HH chickens showed longer DM, whereas HF and OH chickens moved less. The results indicate that hatching system affected broiler activity at specific ages. Effects found at flock level could not be reproduced by individual measurements in study 2, although stocking density was comparable.

Providing light during incubation is being investigated as a method to improve welfare in later life in poultry. This incubation method would more closely approximate chicken natural environment compared to the current incubation in darkness. Previous studies showed promising results of light during incubation on broiler welfare, but little is known about effects of light during incubation on laying hens. Especially, information about its effects on hatching characteristics (hatch time, hatchability, chick quality, body weight and embryonic age of death) is scarce and requires investigation in both white and brown egg layers. In the current study, Dekalb White (DW) and ISA Brown (ISA) eggs were incubated in complete darkness (dark) or in a light:dark cycle of 12L:12D throughout incubation (light), resulting in four treatment groups: DW-dark, DW-light, ISA-dark, and ISA-light. In the light treatments, green LEDs of 520nm wavelength were used, at an intensity of 400lux. First, light transmission through the eggshell was measured through 27 eggs. Then, an analysis of the effects of light during incubation on hatching characteristics was performed on 711 chicks in two consecutive experimental rounds. Light transmission was higher through white eggshells than through brown eggshells (N=27,p< 0.001). Light during incubation had no effects on hatching characteristics (N=711,p≥0.1). Despite the difference of light transmission through eggshell between hybrids, there was no interaction between incubation treatment and hybrid on hatching characteristics (N=471,p≥0.06). Hatch time was longer and navel quality was better in DW than in ISA, while body weight and embryonic age of death were lower in DW than in ISA (allp< 0.001). Males and females had similar chick quality scores except for the beak quality, which was better for males (N=486,p=0.003). To conclude, green light during incubation did not negatively affect hatching characteristics in either DW nor ISA laying hen hybrids. Future research should therefore focus on its potential benefits for laying hen welfare.

Stress is an important factor in animal welfare. Hair or wool cortisol concentrations are considered to be potential long-term indicators of stress experienced by an animal. Using Swifter sheep, we investigated whether ewe parity and litter size affect the wool cortisol concentrations in ewes and their offspring. We hypothesized that multiparous ewes and their offspring would have higher wool cortisol concentrations than primiparous ewes and their offspring, that ewes with larger litters and their offspring would have lower wool cortisol concentrations than ewes with smaller litters and their offspring, that male lambs would have higher wool cortisol concentrations than female lambs, and that the wool cortisol concentrations in the wool of ewes and their lambs would be correlated. Lamb wool grows in utero during the third trimester of pregnancy. In ewes, the shave–reshave method was used so that wool samples from ewes also covered approximately the last trimester of pregnancy. Our study confirmed that litter size affected ewe wool cortisol concentrations: ewes that gave birth to larger litters (i.e., 3 or 4 lambs) had higher wool cortisol concentrations than ewes that gave birth to smaller litters (i.e., 1 or 2 lambs). There was no evidence that the wool cortisol concentrations of the ewes and their lambs were correlated. Neither litter size nor parity of the ewe affected wool cortisol in the lambs. Our study confirms that wool cortisol can be reliably measured in ewes and their newborn lambs, and suggests that it may be useful as a retrospective indicator of stress during the last trimester of pregnancy.

Farm animal veterinarians are frequently involved in animals’ end-of-life (EoL) situations. Existing literature found that the decision-making process to end an animal’s life can be experienced as complex and stressful by veterinarians. The complexity of the process may find its origin in the multiple medical and non-medical aspects that veterinarians consider coming to their decision. Although research provides insight into what considerations are at stake, the literature does not provide information on how these aspects affect the decision-making process. This study explores how different considerations affect the decision-making process of farm animal veterinarians in EoL situations. Semi-structured interviews were conducted with nineteen farm animal veterinarians in the Netherlands. During the interviews, case scenarios in the form of vignettes were used to identify and explore the considerations that play a role for these veterinarians in EoL decision-making. Based on the analysis of the interview data, we discovered that farm animal veterinarians consider EoL situations using one of three identified frames: function, prospect, and duty. These frames illustrate one’s perspective on the interplay of medical and non-medical aspects. Whereas veterinarians for whom the function frame is dominant focus on the human-centred function that an animal fulfils, veterinarians for whom the prospect frame is dominant focus on an animal’s prospects based on the animal’s living conditions and the influence of the owner. Veterinarians for whom the duty frame is dominant focus on the owner’s legal position towards the animal, illustrating a clear distinction between the veterinarian’s professional duties towards the animal and the duty of care of the animal owner. As such, the key contributions of this study are the discovery of the importance of the interplay between considerations in EoL decision-making and the frame-specific approach of veterinarians. The identified frames may relate to the coping strategies of veterinarians dealing with the complexity of EoL situations.

This scientific opinion focuses on the welfare of laying hens, pullets and layer breeders on farm. The most relevant husbandry systems used in Europe are described. For each system, highly relevant welfare consequences were identified, as well as related animal-based measures (ABMs), and hazards leading to the welfare consequences. Moreover, measures to prevent or correct the hazards and/or mitigate the welfare consequences are recommended. The highly relevant welfare consequences based on severity, duration and frequency of occurrence are bone lesions, group stress, inability to avoid unwanted sexual behaviour, inability to perform comfort behaviour, inability to perform exploratory or foraging behaviour, isolation stress, predation stress, resting problems, restriction of movement, skin disorders and soft tissue lesions and integument damage. The welfare consequences of non-cage compared to cage systems for laying hens are described and minimum enclosure characteristics are described for laying hens, pullets and layer breeders. Beak trimming, which causes negative welfare consequences and is conducted to reduce the prevalence and severity of pecking, is described as well as the risks associated with rearing of non-beak-trimmed flocks. Alternatives to reduce sharpness of the beak without trimming are suggested. Finally, total mortality, plumage damage, wounds, keel bone fractures and carcass condemnations are the most promising ABMs for collection at slaughterhouses to monitor the level of laying hen welfare on farm. Main recommendations include housing all birds in non-cage systems with easily accessible, elevated platforms and provision of dry and friable litter and access to a covered veranda. It is further recommended to implement protocols to define welfare trait information to encourage progress in genetic selection, implement measures to prevent injurious pecking, rear pullets with dark brooders and reduce male aggression in layer breeders.

Several physiological characteristics and housing conditions are known to affect hematologic and serum biochemical values in macaques. However, the studies that have been conducted either report values calculated based on a small number of animals, were designed specifically to document the effect of a particular condition on the normal range of hematologic and serum biochemical values, or used parametric assumptions to calculate hematologic and serum biochemical reference intervals. We conducted a retrospective longitudinal cohort study to estimate reference intervals for hematologic and serum biochemical values in clinically healthy macaques based on observed percentiles without parametric assumptions. Data were obtained as part of the Biomedical Primate Research Centre (Rijswijk, The Netherlands) health monitoring program between 2018 and 2021. In total, 4009 blood samples from 1475 macaques were analyzed with a maximum of one repeat per year per animal. Data were established by species, gender, age, weight-for-height indices, pregnancy, sedation protocol, and housing conditions. Most of the parameters profoundly affected just some hematologic and serum biochemical values. A significant glucose difference was observed between the ketamine and ketamine-medetomidine sedation protocols. The results emphasize the importance of establishing uniform experimental groups with validated animal husbandry and housing conditions to improve the reproducibility of the experiments.

Rodent control tends to involve methods that cause animal suffering, but little attention has been paid to the animal welfare implications of rodent control. The aim of the current study was to gain insight into the opinions and attitudes of clients of Dutch pest controllers, regarding liminal rodents, rodent control, and rodent welfare. A better understanding of their attitudes may contribute to more ethical rodent management programmes. An online survey among 248 clients of Dutch pest controllers was carried out. Respondents, especially those within the agricultural sector, have a relatively negative attitude towards rats and mice. Respondents in the agricultural subgroup do not consider the welfare of liminal rodents important. They also think that the welfare impact of commonly used control methods is limited, and they have low tolerance levels for the presence of rodents. Respondents from other sectors have a far more positive attitude towards rats and mice, consider their welfare to be of greater importance, have a greater estimation of the welfare impact of control methods and show greater tolerance levels towards rodents. The respondents from the latter subgroup have a similar attitude compared to Dutch pest controllers participating in a previous survey. The findings of the current study firstly provide useful information for the further development and practical implementation of preventive control methods. Secondly, they provide input for a more animal-friendly rodent control and for the development of an assessment framework to support ethical decision-making. Finally, they can be helpful for further research and the communication and co-operation between professional pest controllers and their clients.

This study aimed to investigate the genetics of rearing success (RS) in laying hens. Four rearing traits: clutch size (CS), first week mortality (FWM), rearing abnormalities (RA), and natural death (ND), were included as factors determining RS. Pedigree, genotypic, and phenotypic records of 4 purebred genetic lines of White Leghorn layers were available for 23,000 rearing batches obtained between 2010 and 2020. FWM and ND showed little or no variation amongst the 4 genetic lines over the years 2010-2020, whereas an increase was observed for CS and a decrease for RA. To determine whether these traits were heritable, genetic parameters for each trait were estimated, using a Linear Mixed Model. Heritabilities within lines were low (0.05-0.19 for CS, 0.01-0.04 for FWM, 0.02-0.06 for RA, 0.02 -0.04 for ND, and 0.01-0.07 for RS). Additionally, genome wide association study was done to scan the genomes of the breeders to reveal single nucleotide polymorphisms (SNPs) associated with these traits. Manhattan plots indicated the existence of 12 differ-ent SNPs having a significant effect on RS. Thus, the identified SNPs will increase the understanding of the genetics of RS in laying hens.

Incubation and hatching commonly takes places at hatcheries, separate from the grow-out facilities where broiler chicks are raised. This means that chicks are sorted and transported immediately after hatch, during which time they typically do not have access to feed and water, and are subjected to transport stress. Recently, innovative housing systems are being developed in which fertilised eggs are transported on embryonic day 18 (E18) from the hatchery to the grow-out facility, where they hatch on day 21. In chicken, the hypothalamic– pituitary–adrenal (HPA)-axis becomes functional around embryonic day 14–16. It is therefore conceivable that transport of eggs at E18 may lead to a stress response in the chick embryo. Exposure to prenatal stress may affect the coping capacity of the individual and negatively impact its further development. We investigated whether prolonged transport on E18 has effects on the development of a slow growing broiler chicken strain (Hubbard JA257). E18 eggs were transported for either 41 min (short transport, ST) or 219 min (long transport, LT). Transportation significantly increased embryonic heart rate after ST. This increase continued during an intermediate measure at 120 min. The increased embryonic HR then remained high at measurement immediately following LT. We did not find effects of prolonged transport on behavioural parameters measured in the juvenile chicken in the tonic immobility and open field test. Concentrations of feather corticosterone as well as faecal corticosterone metabolites did not differ on postnatal day 36. We showed that transport leads to an autonomic stress response in chicken embryos at E18, but that this elevation had no further effects on other indicators of prenatal stress. Nevertheless, our results emphasise that transport of incubated eggs should be as refined as possible to minimise the exposure to stress.

This paper summarises some results of the final report of the research project ‘Systematics of Responsibilities for Animal Welfare in the Livestock Sector’ (2018-2020). The project focused on the question who is fundamentally responsible for the treatment of farm animals. This question is largely and to some extent pointlessly discussed in the public. The study was commissioned by the German Federal Ministry of Agriculture (BMEL). It is based on a systematic examination of the term ‘responsibility’. Responsibility means that agents (who have the necessary means) act accordingly to their value preferences and cause consequences. In this respect, it must be taken into account that animal welfare (as based on altruistic reasoning) is not always given overriding priority in decision-making. This result becomes more plausible when analysing concrete examples of how real decisions were made. The report establishes a characteristic pattern that re-occurs in many discussions on problems in farm animal husbandry: There is an enormous gap between partakers ascribing responsibility to themselves or unto others. The report in contrast uses and extends well established ethical models and principles to create a matrix that makes it possible to say more precisely who is in fact responsible, and why. The report offers a detailed and rather extensive map of possible agents and stakeholders involved in animal husbandry based on the criteria of the matrix. This will lead to a much more distinguished judgement on responsibilities. The project has also developed a database tool in order to locate players in regards to certain characteristics. One result is to filter out those agents who may be called big players in the game at hand. The big food retailers and political bodies are prime candidates. The model can prove why they have indeed an enormous share of responsibility. The role of ‘the consumer’ is in turn to be reconsidered on this basis. The report finally offers an explanation on how responsibility and reliability are interconnected: It is much easier to stick to one’s own responsibilities if other players reliably stick to theirs. In turn, confidence in the system and its elements can be boosted whenever agents evidentially take up their responsibility and do ‘their jobs’

Computer Vision technology has been developed recently as a tool for measuring behaviour on the individual level in group housed livestock. This form of digital agriculture or precision livestock farming has the potential to answer to public concerns on farm animal welfare by using the data to reduce the risk of harmful social interactions such as tail biting in pig production and severe feather pecking in laying hen production. Computer Vision, however comes with changes to livestock farming and therefore can lead to new moral questions. Currently it has not resulted in much public debate. We argue that this is not to be understood as a sign that there are no societal and ethical challenges, but that – as part of responsible research and innovation – this is an important moment to explore and analyse the potential societal and ethical issues. In this paper we aim to explore the moral dimensions of the use of Computer Vision in livestock farming with a special focus on poultry. We analyse the moral dimensions from an animal welfare perspective. Although introduced to prevent welfare risks or improve the welfare status of animals, this innovation can lead to welfare questions depending on one’s concept of animal welfare.

Pig production is related to many societal challenges. This raises the question whether and how pig production systems can be transformed in a way that better includes animal welfare and is responsive to (other) societal concerns. In a project funded by the Netherlands Organisation for Scientific Research (NWO), we focus on the role of resilience to explore the possibilities of defining novel production systems that better match with the interests and adaptive capacities of animals. However, to play this central role, the concept of resilience needs an integrated and transdisciplinary approach. Using the ‘SmartResilience’ project as an example, we argue that to address societal challenges in livestock production it is not sufficient to view one topic through the lenses of multiple disciplines and to produce research results from each discipline which are only supplementary to one another. We argue why complex societal challenges like transforming livestock systems can only be tackled by real collaboration between different disciplines, and why this collaboration already needs to start in the design-phase of innovations. We discuss three stages of collaboration that will lead to a deepened integration of disciplines, which will ultimately result in positive societal impact: (1) identifying the underlying concepts that play a role for achieving the project aim (e.g. animal welfare, resilience); (2) making the implicit assumptions of these concepts explicit by integrating knowledge and methods from different disciplines (e.g. philosophy and animal science); and (3) translating and incorporating the explicit assumptions of concepts into practice and into further actions within the project (e.g. pig breeding or housing strategies). By doing this, we expect to prepare a route forward for more welfare-friendly and sustainable pig production that is in dialogue with society.

The equipment used in broiler breeder houses is an important factor in allowing the expression of the various behaviours of the animals, and thus realizing high welfare standards. Presently, detailed requirements for the equipment in broiler breeder houses are not specified in Germany, especially feed space and perch design allowance. One reason is that basic biometric data on broiler breeders are lacking. To close this gap, a pilot study was conducted, and birds’ width, weight, and feet were measured. Broiler breeders at 22 weeks of age (50 female and 17 male) were weighed and photographed digitally, and their body widths were calculated from the photographs. Female broiler breeders weighed 2791.80 ± 334.99 g on average and showed a body width of 20.63 ± 1.88 cm. For males, a mean of 3615.88 ± 432.46 g was measured with a body width of 21.94 ± 2.32 cm. Our examinations revealed that a trough side length of 21.00 cm per hen and 22.00 cm per cock must be provided to ensure that all broiler breeders have equal access to feed. The same dimensions should be planned as the perch length for each animal. Measurements of broiler breeders’ feet (506 female and 150 male Cobb 500) were performed at 60 weeks of age. The length of each toe and the width and length of the foot pad of both sexes were photographed and measured digitally. Female broiler breeders’ feet showed an average length of 10.14 cm, and male birds showed a length of 12.05 cm. Based on recommendations for the perch design for laying hens, round and oval perches for broiler breeders should have a circumference of at least 11.30 cm (female) or 13.40 cm (male). For angular perches, the upper contact area should have a width of 2.80 cm (female) or 3.40 cm (male). The obtained biometric data could be a useful basis for the development of legal requirements for broiler breeders.

Throughout the world, most laying hens producing eggs for human consumption are still kept in small, wire battery cages. Ethologists have well documented the behavioural needs of hens, and the way that battery cage confinement thwarts highly motivated behaviour and reduces hens’ quality of life. While cage-free alternatives are now being used around the world, the more challenging management in these systems has contributed to the slower than desired uptake that would be necessary for improving hens’ welfare. As part of the 2021 Interna- tional Society for Applied Ethology (ISAE) virtual conference, a workshop was held with the aim to identify solutions to the common challenges. Attendees were given information about cage-free production and then sectioned into breakout groups for discussion. Following the workshop, they were asked to participate in a short survey. Breakout sessions included the topics of stakeholder engagement and further research needs, as well as identification of solutions to the common challenges. Across the two days of the workshop, there were 80 participants, from 27 countries, mostly ethologists (both students and non-students), but including egg pro- ducers, and representatives from government and non-governmental (NGO) organizations. Of the 80 partici- pants, 35 completed the survey. Participants generated many insightful and practical ideas in both the breakout rooms and in the survey, but one particularly salient theme was that solutions already exist and what is needed is greater education and dissemination of technical knowledge (half of survey responses from participants in the developed world and 42% of ethologist’s responses fit within the theme of established producers assisting new producers or producer education and training). This was further evidenced by the noted success of cage-free producers in a variety of different geographic areas, climates, production scales and in both developed and developing regions. It was concluded that cross-sector collaboration will be necessary to speed up the transition to cage-free housing, with roles to play by the producers’ egg buying customers (retailers), end consumers, government and NGOs, and researchers. There are multiple paths forward, with many different approaches possible simultaneously, and the potential to free many more hens from their cages is promising.

Severe feather pecking, the pulling out of feathers of conspecifics, is a major welfare issue in laying hens. Possible underlying causes are fearfulness and lack of foraging opportunities. Because early life is a crucial stage in behavioral development, adapting the incubation and rearing environment to the birds' needs may reduce fearfulness and prevent the development of feather pecking. In a 2 × 2 factorial design study, we investigated whether a green light-dark cycle throughout incubation, which resembles natural incubation circumstances more than the standard dark incubation, and foraging enrichment with live larvae during rearing reduce fearfulness and feather pecking and increase foraging behavior of laying hen pullets from an early age onwards. In this 2-batch experiment, 1,100 ISA Brown eggs were incubated under either 0 h of light/24 h of darkness or 12 h of green LED light/12 h of darkness. After hatching, 400 female chicks (200 per batch) were housed in 44 pens (8–10 chicks per pen). During the entire rearing phase (0–17 wk of age), half of the pens received black soldier fly larvae in a food puzzle as foraging enrichment. We assessed fear of novel objects and humans, feather pecking, plumage condition, foraging behavior, and recovery time after a 3-fold vaccination (acute stressor). A slight increase in the number of foraging bouts was only seen with larvae provisioning (rate ratio 1.19, 95% CI 1.02–1.29, P = 0.008). Neither lighted incubation nor larvae provisioning affected fearfulness, feather pecking, plumage condition or recovery time after vaccination. In conclusion, the present study showed no effects of light during incubation and minor effects of foraging enrichment during rearing on the behavior of laying hen pullets. Further research is recommended on other welfare aspects.

Animal behaviour is complex and comparing average levels of behavioural activities is sometimes insufficient to pick up on behavioural differences between (groups of) animals. Entropy, a measure of the randomness or regularity of time series, might help us to describe aspects of behaviour better. In this study, we determined daily entropy in individual broiler activity levels over time, based on a time series of observed activity per 15 minutes across a day, to assess individual variation and consistency in entropy of activity. Activity data for calculation of entropy were available for 79 broilers for a maximum of 21 days. We observed individual variation in entropy between broilers, but the level of entropy was not very consistent across days. The individual variation in entropy indicates potential for future research to look into whether and how entropy differences relate to other traits in broilers.

Individual activity is related to the health, welfare and performance of broilers. In previous work using a radio frequency identification system, we were able to collect individual activity data over time, and activity was found to be heritable. The aim of the current study was to estimate genetic parameters for activity while taking into account the effect of age. Therefore, two repeated measurement models were fitted. The model with an intercept and slope for genetic and permanent environmental effect, and a heterogeneous residual variance, yielded the best goodness-of-fit. First results showed that daily heritability varied between 7 and 30%. The heritability was lowest at the start and at the end of the production life. This study shows potential for selection on activity in broilers. Furthermore, this study shows that activity patterns (in time) can be changed, as both the intercept and slope of activity are heritable.

To avoid the killing of surplus male layer chickens, dual-purpose hybrids are suggested as an alternative approach. These strains may offer additional advantages compared to conventional laying hens, for instance, a lower tendency to develop injurious pecking behavior. The aim of this study was to assess the behavior, with focus on pecking behavior, of conventional layers (Lohmann Brown plus, LB+) and dual-purpose hens (Lohmann Dual, LD). About 1,845 hens per strain with intact beaks were housed in four stable compartments in aviary systems. Video-based scan sampling of general behaviors and continuous observations of pecking behavior were carried out between 25 and 69 weeks of life. With the exception of “dustbathing” and “scratching,” hybrid × time during the laying period affected all of the observed general behaviors [F(2, 89) = 3.92–10.81, P < 0.001–0.05]. With increasing age, the LB+ hens performed more general pecking, more locomotion and less comfort and sitting behavior. General pecking and comfort behavior did not change over time in the LD hens, whereas inactive behaviors increased with age. During continuous observations, a significant hybrid x period interaction was found for all forms of pecking behavior [F(2, 89) = 4.55–14.80, P < 0.001–0.05]. The LB+ hens showed particularly more severe feather pecking (SFP), which increased with age. In contrast, SFP remained exceptionally low in the LD hens throughout production. Therefore, dual-purpose hybrids should be considered as an alternative to both avoid the killing of surplus male chickens and the development of SFP in laying hen production.

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.

Modern welfare definitions not only require that the Five Freedoms are met, but animals should also be able to adapt to changes (i. e., resilience) and reach a state that the animals experience as positive. Measuring resilience is challenging since relatively subtle changes in animal behavior need to be observed 24/7. Changes in individual activity showed potential in previous studies to reflect resilience. A computer vision (CV) based tracking algorithm for pigs could potentially measure individual activity, which will be more objective and less time consuming than human observations. The aim of this study was to investigate the potential of state-of-the-art CV algorithms for pig detection and tracking for individual activity monitoring in pigs. This study used a tracking-by-detection method, where pigs were first detected using You Only Look Once v3 (YOLOv3) and in the next step detections were connected using the Simple Online Real-time Tracking (SORT) algorithm. Two videos, of 7 h each, recorded in barren and enriched environments were used to test the tracking. Three detection models were proposed using different annotation datasets: a young model where annotated pigs were younger than in the test video, an older model where annotated pigs were older than the test video, and a combined model where annotations from younger and older pigs were combined. The combined detection model performed best with a mean average precision (mAP) of over 99.9% in the enriched environment and 99.7% in the barren environment. Intersection over Union (IOU) exceeded 85% in both environments, indicating a good accuracy of the detection algorithm. The tracking algorithm performed better in the enriched environment compared to the barren environment. When false positive tracks where removed (i.e., tracks not associated with a pig), individual pigs were tracked on average for 22.3 min in the barren environment and 57.8 min in the enriched environment. Thus, based on proposed tracking-by-detection algorithm, pigs can be tracked automatically in different environments, but manual corrections may be needed to keep track of the individual throughout the video and estimate activity. The individual activity measured with proposed algorithm could be used as an estimate to measure resilience.

Traditionally, broiler chickens hatch in the hatchery and they are usually not provided with feed and water until placement at the farm. This can have negative effects on their health and welfare. Therefore, alternative systems providing early nutrition, for instance by hatching eggs in a poultry house (on-farm hatching) are increasingly being used in practice. However, information on the behaviour and welfare of on-farm hatched chickens in relation to hatchery-hatched chickens is very limited. This study aims to gain basic knowledge of the behaviour of on-farm hatched chickens (OH) by comparing them to a control group (C) hatched in the hatchery. In addition, fear-related responses were assessed as indicators of chicken welfare. About 13,800 chickens per treatment group were reared in three consecutive batches in eight floor pens under semi-commercial conditions. Direct behavioural observations and three different fear tests, i.e. a novel environment, a human approach and a novel object test, were carried out between two and 36 days of age. Except for ‘disturbance behaviour’ (i.e. pushing or overrunning another chicken), which was more often performed by the OH chickens (F1,3 = 35.10, P < 0.05), no effect of treatment was found on general behaviour. In contrast, nearly all observed behaviours were affected by the chickens’ age (F4,24 = 4.02–41.81, P < 0.05). In the fear tests, most variables, for instance average latency of chickens touching a human and the number of chickens in the vicinity of a novel object, differed between the treatments (P < 0.05) with OH chickens being more fearful and less active. The present results indicate that the hatching system (hatchery-hatching vs. on-farm hatching) seems to have limited effects on broiler chicken activity and general behaviours. In test situations, however, hatchery-hatched chickens showed more active and less fearful responses compared to on-farm hatched chickens. The underlying causes for these differences in response to more challenging situations remain to be investigated further, as these may be related to a higher intrinsic motivation to search for food or more exposure to humans or objects in the hatchery in C chickens as compared to OH chickens, but also to differences in coping style or development of cognitive abilities between the treatment groups.

In pigs, higher birth order is associated with higher pre-weaning mortality. However, knowledge on the effect of birth order on welfare of surviving piglets is limited. The aim of this study was to explore the possible link between birth order and both newborn piglet performance and later affective state. Firstly, the following data were collected in 393 piglets from 27 litters: stillbirth, intactness of the umbilical cord and birth weight. Subsets of piglets were used to measure suckling latency (n = 67) and teat order (n = 21). Secondly, a subset of first-born (n = 9) and last-born (n = 7) piglets were trained to perform an active-choice judgement bias task (JBT). During discrimination training preceding the JBT, the pigs learned to associate two tone cues with the availability of either a large (4 M&M's® Milk Chocolate candies) or small (1 M&M's) reward, provided at two different locations. After training, ambiguous intermediate tones were introduced and the pig's choice of location was scored as either optimistic or pessimistic. Results showed that last-born piglets had a higher birth weight than middle-born piglets, while first-born piglets did not significantly differ from last- or middle-born piglets. They also latched to more caudal teats than first-born piglets. The last-born and first-born piglets showed a similar learning rate during discrimination training, and a similar latency to approach reward locations, and had a similar optimistic bias in the JBT.