Genetic parameter estimates for the use of an aviary with winter garden by laying hens.

The behavioral activity of laying hens in an aviary is indicative of their welfare and health. Furthermore, hens' usage of the different locations within an aviary has been shown to influence laying performance and egg quality. For example, hens that spent a longer duration of time in the nest during laying were observed to have lower laying performance.

Welfare of broilers on farm.

This Scientific Opinion considers the welfare of domestic fowl () related to the production of meat (broilers) and includes the keeping of day-old chicks, broiler breeders, and broiler chickens. Currently used husbandry systems in the EU are described. Overall, 19 highly relevant welfare consequences (WCs) were identified based on severity, duration and frequency of occurrence: 'bone lesions', 'cold stress', 'gastro-enteric disorders', 'group stress', 'handling stress', 'heat stress', 'isolation stress', 'inability to perform comfort behaviour', 'inability to perform exploratory or foraging behaviour', 'inability to avoid unwanted sexual behaviour', 'locomotory disorders', 'prolonged hunger', 'prolonged thirst', 'predation stress', 'restriction of movement', 'resting problems', 'sensory under- and overstimulation', 'soft tissue and integument damage' and 'umbilical disorders'.

Intra-individual variation of hen movements is associated with later keel bone fractures in a quasi-commercial aviary.

Measuring intra- and inter-individual variation in movement can bring important insights into the fundamental ecology of animals and their welfare. Although previous studies identified consistent differences in movements of laying hens within commercial aviaries, the level of consistency was not quantified, limiting our capacity to understand the importance of individual movements for welfare. We aimed to quantify the scope of intra- and inter-individual differences in movements of commercial laying hens and examined their associations with indicators of welfare at the end of production.

Effect of perch access on perching, health and production outcomes in commercial broiler breeder flocks.

There is a need for more knowledge about perch use in broiler breeders and the potential effects of perches on health and production outcomes. The aim of this study was to investigate the use of perches by commercial broiler breeders, effect of perch access on keel bone fractures (KBF), footpad dermatitis (FPD) and number of floor eggs. Two commercial breeder flocks (Ross 308) reared at the same facility were observed during the production period.

High resolution parallel sequencing reveals multistrain Campylobacter in broiler chicken flocks testing 'negative' by conventional culture methods: implications for control of Campylobacter infection.

Contaminated chicken meat is a major source of human Campylobacteriosis and rates of infection remain high, despite efforts to limit the colonisation of broiler (meat) chicken flocks on farms. Using conventional testing methods of culture or qPCR, Campylobacter is typically detected amongst broiler flocks from 3 wk of age, leading to the assumption that infection is introduced horizontally into chicken rearing houses at this time. In this study, we use parallel sequencing of a fragment of the Campylobacter outer membrane protein, encoded by the porA gene, to test for presence of Campylobacter DNA amongst fresh fecal samples collected from broiler flocks aged 23 to 28 d.

Skeletal variation in bird domestication: limb proportions and sternum in chicken, with comparisons to mallard ducks and Muscovy ducks.

Background: Domestication, including selective breeding, can lead to morphological changes of biomechanical relevance. In birds, limb proportions and sternum characteristics are of great importance and have been studied in the past for their relation with flight, terrestrial locomotion and animal welfare. In this work we studied the effects of domestication and breed formation in limb proportions and sternum characteristics in chicken (), mallard ducks () and Muscovy ducks ().

Similarity in Temporal Movement Patterns in Laying Hens Increases with Time and Social Association.

We explored the relationship between social associations and individual activity patterns in domestic hens. Out of 1420 laying hens, 421 hens were equipped with RFID tags attached to RFID-specific leg bands (leg bands from Company Roxan, Selkirk, Scotland) to continuously track their change in location across four different areas (one indoor and three outdoor areas). Using a combination of social network analysis for quantifying social relationships and dynamic time warping for characterizing the movement patterns of hens, we found that hens were consistent in their individual variation in temporal activity and maintained stable social relationships in terms of preferred association partners.

Parallel Sequencing Reveals Campylobacter spp. in Commercial Meat Chickens Less than 8 Days Old.

Campylobacter from contaminated poultry meat is a major source of human gastroenteritis worldwide. To date, attempts to control this zoonotic infection with on-farm biosecurity measures have been inconsistent in outcome. A cornerstone of these efforts has been the detection of chicken infection with microbiological culture, where Campylobacter is generally not detectable until birds are at least 21 days old.

Groups and Individuals: Optical Flow Patterns of Broiler Chicken Flocks Are Correlated with the Behavior of Individual Birds.

Group level measures of welfare flocks have been criticized on the grounds that they give only average measures and overlook the welfare of individual animals. However, we here show that the group-level optical flow patterns made by broiler flocks can be used to deliver information not just about the flock averages but also about the proportion of individuals in different movement categories. Mean optical flow provides information about the average movement of the whole flock while the variance, skew and kurtosis quantify the variation between individuals.

Cell Proliferation in the Adult Chicken Hippocampus Correlates With Individual Differences in Time Spent in Outdoor Areas and Tonic Immobility.

Access to outdoor areas is provided as a means of enhancing welfare in commercial systems for laying hens (), but substantial individual differences exist in their proportional use. Baseline cell proliferation levels of Adult Hippocampal Neurogenesis (AHN) have been associated with individual differences in reactive vs. proactive coping style, and in both mammals and birds, AHN is upregulated by positive experiences including environmental enrichment and exercise.

Evaluation of Poultry Stunning with Low Atmospheric Pressure, Carbon Dioxide or Nitrogen Using a Single Aversion Testing Paradigm.

Low atmospheric pressure stunning (LAPS) has been suggested for use in poultry under 4 kg in the abattoir as a more humane alternative to carbon dioxide (CO). However, there are currently no studies offering a direct comparison of the aversion between methods. Here, we trained adult female broiler breeders to relinquish a food reward by moving to another area of the gas chamber in response to aversive stimuli.

DNA methylation variation in the brain of laying hens in relation to differential behavioral patterns.

Domesticated animals are unique to investigate the contribution of genetic and non-genetic factors to specific phenotypes. Among non-genetic factors involved in phenotype formation are epigenetic mechanisms. Here we aimed to identify whether relative DNA methylation differences in the nidopallium between groups of individuals are among the non-genetic factors involved in the emergence of differential behavioral patterns in hens.

The influence of human interaction on guinea pigs: Behavioral and thermographic changes during animal-assisted therapy.

Guinea pigs are often involved in animal-assisted therapy (AAT) but there is little knowledge about the effects of human contact on guinea pigs involved in AAT. The aim of this study was to investigate effects of availability of a retreat, presence of conspecifics, prior experience with AAT, and human interaction on indicators of welfare in guinea pigs involved in AAT. Guinea pigs of both sexes and different ages (n=20) were assigned to a randomized, controlled within-subject trial with repeated measurements.

Improving intra- and inter-observer repeatability and accuracy of keel bone assessment by training with radiographs.

Assessing keel bone damage reliably and accurately is a requirement for all research on this topic. Most commonly, assessment is done on live birds by palpation and is therefore prone to bias. A 2-day Training School of the COST Action "Identifying causes and solutions of keel bone damage in laying hens" with 16 participants of variable experience was held where palpation of live hens was followed by consulting corresponding radiographic images of keel bones.

A Systematic Review of Precision Livestock Farming in the Poultry Sector: Is Technology Focussed on Improving Bird Welfare?

Precision livestock farming (PLF) systems have the potential to improve animal welfare through providing a continuous picture of welfare states in real time and enabling fast interventions that benefit the current flock. However, it remains unclear whether the goal of PLF development has been to improve welfare or increase production efficiency. The aims of this systematic literature review are to provide an overview of the current state of PLF in poultry farming and investigate whether the focus of PLF research has been to improve bird welfare.

Influence of the microbiota-gut-brain axis on behavior and welfare in farm animals: A review.

There is increasing evidence of a pivotal role of the gut microbiota (GUT-M) in key physiological functions in vertebrates. Many studies discuss functional implications of the GUT-M not only on immunity, growth, metabolism, but also on brain development and behavior. However, while the influence of the microbiota-gut-brain axis (MGBA) on behavior is documented in rodents and humans, data on farm animals are scarce.

Improving intra- and inter-observer repeatability and accuracy of keel bone assessment by training with radiographs.

Assessing keel bone damage reliably and accurately is a requirement for all research on this topic. Most commonly, assessment is done on live birds by palpation and is therefore prone to bias. A 2-day Training School of the COST Action "Identifying causes and solutions of keel bone damage in laying hens" with 16 participants of variable experience was held where palpation of live hens was followed by consulting corresponding radiographic images of keel bones.

Frequent range visits further from the shed relate positively to free-range broiler chicken welfare.

Little is known about the implications of accessing an outdoor range for broiler chicken welfare, particularly in relation to the distance ranged from the shed. Therefore, we monitored individual ranging behaviour of commercial free-range broiler chickens and identified relationships with welfare indicators. The individual ranging behaviour of 305 mixed-sex Ross 308 broiler chickens was tracked on a commercial farm from the second day of range access to slaughter age (from 16 to 42 days of age) by radio frequency identification (RFID) technology.

Progression and risk factors of pododermatitis in part-time group housed rabbit does in Switzerland.

In rabbits (Oryctolagus cuniculus L.), pododermatitis is a chronic multifactorial skin disease that appears mainly on the plantar surface of the hind legs. This presumably progressive disease can cause pain leading to poor welfare, yet the progression of this disease has not been thoroughly assessed on the level of individual animals.

Pododermatitis in group housed rabbit does in Switzerland-Prevalence, severity and risk factors.

In rabbits (Oryctolagus cuniculus L.), pododermatitis is a chronic multifactorial skin disease that appears mainly on the plantar surface of the hind legs. In later stages, it causes pain leading to poor welfare of affected animals.

Ranging behavior relates to welfare indicators pre- and post-range access in commercial free-range broilers.

Little is known about the effect of accessing an outdoor range on chicken welfare. We tracked individual ranging behavior of 538 mixed-sex Ross 308 chickens on a commercial farm across 4 flocks in winter and summer. Before range access, at 17 to 19 d of age, and post-range access, at 30 to 33 and 42 to 46 d of age in winter and summer flocks respectively, welfare indicators were measured on chickens (pre-range: winter N = 292; summer N = 280; post-range: winter N = 131; summer N = 140), including weight, gait score, dermatitis and plumage condition.

Relationship between welfare and individual ranging behaviour in commercial free-range laying hens.

Laying hens housed in free-range systems have access to an outdoor range, and individual hens within a flock differ in their ranging behaviour. Whether there is a link between ranging and laying hen welfare remains unclear. We analysed the relationships between ranging by individual hens on a commercial free-range layer farm and behavioural, physiological and health measures of animal welfare.

Perch use by broiler breeders and its implication on health and production.

Broiler breeders are commonly kept without perches, although perching has been shown to be a high-priority behavior in laying hens. We studied whether broiler breeders used elevated perches of different lengths during the night and how access to perches affected health and production. Using the Ross 308 hybrid, pens offering 4 different perch spaces per bird (5, 10, 14, and 20 cm) in a cross-over design were compared with pens without perches.

Susceptibility to keel bone fractures in laying hens and the role of genetic variation.

Keel bone fractures are a well-known welfare problem in modern commercial laying hen systems. The present study sought to identify genetic variation in relation to keel bone fracture susceptibility of 4 distinct crossbred and one pure line, and by extension, possible breeding traits. Susceptibility to fractures were assessed using an ex vivo impact testing protocol in combination with a study design that minimized environmental variation to focus on genetic differences.

Limited Associations between Keel Bone Damage and Bone Properties Measured with Computer Tomography, Three-Point Bending Test, and Analysis of Minerals in Swiss Laying Hens.

Keel bone damage is a wide-spread welfare problem in laying hens. It is unclear so far whether bone quality relates to keel bone damage. The goal of the present study was to detect possible associations between keel bone damage and bone properties of intact and damaged keel bones and of tibias in end-of-lay hens raised in loose housing systems.