Active walking in broiler chickens: a flagship for good welfare, a goal for smart farming and a practical starting point for automated welfare recognition.

Automated assessment of broiler chicken welfare poses particular problems due to the large numbers of birds involved and the variety of different welfare measures that have been proposed. Active (sustained, defect-free) walking is both a universally agreed measure of bird health and a behavior that can be recognized by existing technology. This makes active walking an ideal starting point for automated assessment of chicken welfare at both individual and flock level.

Natural Behaviour Is Not Enough: Farm Animal Welfare Needs Modern Answers to Tinbergen's Four Questions.

Despite the many scientific objections that have been raise to it, 'natural behaviour' is widely used as an indication of good welfare by the food industry. The supposed link between welfare and natural behaviour derives, however, from a now outdated view of animals becoming frustrated if they cannot perform their natural instinctive behaviour. On the 60th anniversary of its publication, Niko Tinbergens' Four Questions framework is used to show why there is no necessary link between natural behaviour and welfare and why, therefore, reliance on natural behaviour in commercial farming may not result in the claimed improvements in welfare.

Farm animal welfare: Beyond "natural" behavior.

An animal-centered view guided by what animals value could improve welfare on farms.

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.

Animal Welfare and Resistance to Disease: Interaction of Affective States and the Immune System.

Good management and improved standards of animal welfare are discussed as important ways of reducing the risk of infection in farm animals without medication. Increasing evidence from both humans and animals suggests that environments that promote wellbeing over stress and positive over negative emotions can reduce susceptibility to disease and/or lead to milder symptoms. We point out, however, that the relationship between welfare, immunity, and disease is highly complex and we caution against claiming more than the current evidence shows.

Can good broiler flock welfare prevent colonization by Campylobacter?

Using data on rearing and welfare metrics of multiple commercial broiler flocks, we investigate how welfare measures such as hock burn, mortality, and pododermatitis, among others, impact the likelihood of a flock becoming colonized by Campylobacter. Using both logistic regression and Bayesian networks, we show that, while some welfare metrics were weakly related to Campylobacter colonization, evidence could not be found to suggest that these metrics directly exacerbated Campylobacter colonization, rather that they were both symptoms of the same parent variable - the managing company. Observed dependency on the management of the flock suggested that yet-undiscovered differences in rearing practice were the principal factor explaining both poor bird welfare and increased risk of Campylobacter, suggesting that action can be taken to improve both these factors simultaneously.

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.

A Mathematical Modeling Approach to Uncover Factors Influencing the Spread of in a Flock of Broiler-Breeder Chickens.

Despite continued efforts to improve biosecurity protocols, continues to be detected in the majority of commercial chicken flocks across Europe. Using an extensive data set of prevalence within a chicken breeder flock for over a year, multiple Bayesian models are presented to explore the dynamics of the spread of in response to seasonal variation, species-specificity, bird health, and total colonization prevalence. These models indicated that birds within the flock varied greatly in their response to bacterial challenge, and that this phenomenon had a large impact on the overall prevalence of different species of .

Utilization of Optical Flow Algorithms to Monitor Development of Tail Biting Outbreaks in Pigs.

A study was conducted to evaluate activity changes in pigs associated with the development of tail-biting outbreaks using optical flow algorithms. Pigs ( = 120; initial body weight = 25 ± 2.9 kg) housed in four pens of 30 pigs were studied for 13 weeks.

Dominance, sharing, and assessment in an iterated Hawk-Dove game.

Animals use a wide variety of strategies to reduce or avoid aggression in conflicts over resources. These strategies range from sharing resources without outward signs of conflict to the development of dominance hierarchies, in which initial fighting is followed by the submission of subordinates. Although models have been developed to analyse specific strategies for resolving conflicts over resources, little work has focused on trying to understand why particular strategies are more likely to arise in certain situations.

A Mathematical Model of Dynamics Within a Broiler Flock.

Globally, the bacterial genus is one of the leading causes of human gastroenteritis, with its primary route of infection being through poultry meat. The application of biosecurity measures is currently limited by a lack of understanding of the transmission dynamics within a flock. Our work is the first to undertake a mathematical modeling approach to population dynamics within a flock of broilers (chickens bred specifically for meat).

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.

Modeling the lowest-cost splitting of a herd of cows by optimizing a cost function.

Animals live in groups to defend against predation and to obtain food. However, for some animals-especially ones that spend long periods of time feeding-there are costs if a group chooses to move on before their nutritional needs are satisfied. If the conflict between feeding and keeping up with a group becomes too large, it may be advantageous for some groups of animals to split into subgroups with similar nutritional needs.

Monitoring chicken flock behaviour provides early warning of infection by human pathogen Campylobacter.

Campylobacter is the commonest bacterial cause of gastrointestinal infection in humans, and chicken meat is the major source of infection throughout the world. Strict and expensive on-farm biosecurity measures have been largely unsuccessful in controlling infection and are hampered by the time needed to analyse faecal samples, with the result that Campylobacter status is often known only after a flock has been processed. Our data demonstrate an alternative approach that monitors the behaviour of live chickens with cameras and analyses the 'optical flow' patterns made by flock movements.

Prediction of welfare outcomes for broiler chickens using Bayesian regression on continuous optical flow data.

Currently, assessment of broiler (meat) chicken welfare relies largely on labour-intensive or post-mortem measures of welfare. We here describe a method for continuously and robustly monitoring the welfare of living birds while husbandry changes are still possible. We detail the application of Bayesian modelling to motion data derived from the output of cameras placed in commercial broiler houses.

Commercial scale research and assessment of poultry welfare.

1. Commercial level research on poultry welfare is increasingly important because of the insight it gives into what improves welfare in the context of other important drivers such as human health, environmental impact and cost. 2.

Prediction of feather damage in laying hens using optical flows and Markov models.

Feather pecking in laying hens is a major welfare and production problem for commercial egg producers, resulting in mortality, loss of production as well as welfare issues for the damaged birds. Damaging outbreaks of feather pecking are currently impossible to control, despite a number of proposed interventions. However, the ability to predict feather damage in advance would be a valuable research tool for identifying which management or environmental factors could be the most effective interventions at different ages.

Campylobacter infection of broiler chickens in a free-range environment.

Campylobacter jejuni is the most common cause of bacterial gastroenteritis worldwide, with contaminated chicken meat considered to represent a major source of human infection. Biosecurity measures can reduce C. jejuni shedding rates of housed chickens, but the increasing popularity of free-range and organic meat raises the question of whether the welfare benefits of extensive production are compatible with food safety.

Report of the Working Group on Animal Distress in the Laboratory.

Finding ways to minimize pain and distress in research animals is a continuing goal in the laboratory animal research field. Pain and distress, however, are not synonymous, and measures that alleviate one may not affect the other. Here, the authors provide a summary of a meeting held in February 2004 that focused on distress in laboratory animals.

A user's guide to animal welfare science.

Here, I provide a guide for those new to the burgeoning field of animal welfare science as to what this comprehensive, relatively young discipline is all about. Drawing on all branches of biology, including behavioural ecology and neuroscience, the science of animal welfare asks three big questions: Are animals conscious? How can we assess good and bad welfare in animals? How can we use science to improve animal welfare in practice? I also provide guidelines for an evidence-based approach to welfare issues for policy makers and other users of animal welfare research.

Behaviour as a tool in the assessment of animal welfare.

A central issue in animal welfare research is how to assess the welfare state of animals objectively and scientifically. I argue that this issue can be approached by asking two key questions: 1) is the animal physically healthy and 2) does the animal have what it wants? Behaviour is used to answer both of these questions. In the assessment of physical health, it can be used for clinical and pre-clinical diagnosis.

Chicken welfare is influenced more by housing conditions than by stocking density.

Intensive broiler (meat) chicken production now exceeds 800 million birds each year in the United Kingdom and 2 x 10(10) birds worldwide, but it attracts accusations of poor welfare. The European Union is currently adopting standards for broilers aimed at a chief welfare concern--namely, overcrowding--by limiting maximum 'stocking density' (bird weight per unit area). It is not clear, however, whether this will genuinely improve bird welfare because evidence is contradictory.

ARE WARNING COLORS HANDICAPS?

The handicap theory, in which the cost of waste guarantees honest advertising, is being used increasingly in solutions to the problems of biological signal evolution. However, it is usually applied to systems which are insufficiently understood to allow testing against alternative theories. In particular, the ability of the handicap theory to explain the design of signals has never been properly tested.