Award details

The defence cascade as an indicator of animal welfare in the lab and field

Reference	BB/I005641/1
Principal Investigator / Supervisor	Professor Michael Mendl
Co-Investigators / Co-Supervisors	Professor William Browne, Dr Neill Campbell, Professor Emma Robinson
Institution	University of Bristol
Department	Clinical Veterinary Science
Funding type	Research
Value (£)	588,271
Status	Completed
Type	Research Grant
Start date	01/08/2011
End date	31/07/2015
Duration	48 months

Abstract

This project will develop a new method for assessing animal welfare in the lab and field. Good field-based measures are needed because welfare criteria are important components of on-farm quality assurance schemes. However, most field-based measures provide limited information on the affective states of animals which are central to people's concerns about welfare. The defensive responses shown to an alerting stimulus (e.g. startle / orientation, freezing / evaluation, fleeing or resuming ongoing behaviour) may reflect underlying affective states. Theory, and studies of humans and rodents, suggest that this 'defence cascade' (DC) is modulated by affect. Individuals in a negative state are predicted to: show a stronger and faster initial startle response; be more likely to show a final fleeing response; make this decision faster; be slower to make a final decision to stay put, than individuals in a positive state. We will test these predictions in an important farmed species, the pig, which shows a clear DC response. We will first develop a method for measuring DC responses that uses computational image analysis (IA) of videos of the behaviour. Readouts from computational IA will be correlated with simultaneously collected 'gold standard' measures of DC responses (force plate, behavioural observation) in singly tested pigs to identify the best correlated measures. These IA measures will then be used to quantify DC responses of individual pigs in groups (group housing is the norm on farms) and to develop novel emergent measures of group response. The effects of manipulations of affect / welfare on IA measures will be used to test the predictions listed above. IA measures that best reflect affective modulation of DC responses will then be trialled on farms. The relationship between DC responses, independent assessments of welfare, and other 'background' variables will be determined using multi-level modelling.

Summary

The assumption that non-human animals can subjectively experience negative emotional states, and hence suffer, underlies many people's concerns about animal welfare. Whilst we cannot measure the subjective states of other animals directly, it is important that we develop accurate indirect measures. It is also important that these measures can be used in both lab and field, especially on farms. This is because assessment of welfare is becoming a significant part of on-farm quality assurance schemes which aim to provide reliable information for the consumer about how food is produced. These schemes tend to assess welfare by measuring the resources available to animals (e.g. trough space) - a very indirect measure - or physical damage to the animal which may only reveal relatively severe problems. We aim to develop a new measure of welfare that more closely reflects the emotional states which lie at the heart of animal welfare concerns. This measure will also be of value in lab studies, precluding the need to isolate animals for testing. When animals are disturbed by an alerting stimulus that may signal danger (e.g. loud noise), they show a suite of defensive responses including startle and orientation, freezing and evaluation of the situation, and a final response of fleeing or resuming ongoing behaviour. Theoretical predictions, and studies of humans and rodents, suggest that the components of this 'defence cascade' (DC) are modulated by the individual's emotional state. For example, individuals in a negative state are predicted to show a stronger and faster initial startle response, to be more likely to show a final fleeing response, to make this decision faster, and to be slower to make a final decision to stay put, than individuals in a positive state. We will test these predictions in an important farmed species, the domestic pig. The pig shows a clear DC response to sudden noises (e.g. door slam), and we will develop standardised methods for inducing this response. Parts of the DC have been studied in humans and rodents under 'gold standard' laboratory conditions using force plate technology. It would be impractical to use such equipment on farms, but video images of the defence cascade could easily be collected and analysed to quantify the response. To develop these video-based methods, we will study individual pigs' DC responses under controlled conditions where we can obtain video and force plate data simultaneously. We will use computational image analysis to derive numerical output from the video footage and correlate this with the conventional 'gold standard' measures to determine whether image analysis accurately measures the DC response. We will also develop novel image analysis measures of group DC responses (pigs are usually group housed) - e.g. how rapidly a response spreads across a group - and investigate whether manipulation of welfare / emotional state (e.g. by housing groups in different conditions) affects DC responses as predicted above. We will then trial the image analysis measures of DC responses that best reflect emotional state / welfare on farms. Because the image analysis approach we use does not need to identify individual animals, we anticipate that it will cope with the visual challenges of a 'real-life' farm environment. We will accompany farm assurance assessors to farms, measure DC responses, collect data on the conditions on farms and in pens, and evaluate the relationships between these different measures using statistical techniques. This will show us how our DC measures reflect independent assessments of welfare at farm and pen level. We thus hope to produce a validated, non-invasive, quick and practical method for measuring animal welfare that can be adapted to other species, can be used in the field as well as the lab (including as part of farm assurance audits), and gets closer to reflecting the important emotional component of welfare than any existing field-based measure.

Impact Summary

Our project will deliver tools and techniques for generating and monitoring defence cascade responses as validated indicators of animal affect and welfare under 'real-life' farm, and laboratory, conditions. It will have a number of benefits outside the academic sector. In the livestock industry, farm quality assurance schemes are increasingly keen to incorporate welfare measures based on the animal (rather than the resources provided) into their assessments. Our approach offers just such a measure, designed to reflect the animal's affective state - the core of people's concerns about welfare. Because of the image analysis procedures used, the approach should be readily generalisable beyond pigs (our study species) and hence applicable to a wide range of on-farm quality assurance schemes. It will benefit these schemes, the livestock industry, and the general public, by enhancing the scientific validity of on-farm welfare assessment, providing more accurate information for the public and decision makers, and contributing to improved quality of life for farm animals, and resulting product quality. We have agreement for collaboration within this project from the British Pig Executive (BPEX), the main pig industry levy board which is directly involved in livestock assurance schemes, allowing us to communicate findings directly to our industry contacts, as well as more generally through articles in the pig industry press. Our approach may also offer a new home-cage, group-based method for affect assessment in lab animals that alleviates the need for the stressful handling and isolation of animals that are tested in conventional Skinner box 'startle tests'. Any potential for further development and 'roll out' of this approach will be explored through our links with pharmaceutical companies (e.g. Pfizer, MSD). As well as providing a stronger scientific basis underpinning the quality assurance criteria upon which some members of the public base their food-purchasing decisions, the research will raise general public interest issues to do with 'animal mind' and 'animal emotion'. We will communicate relevant findings through press releases, articles in popular science magazines, public talks and exhibits (e.g. National Science and Engineering Week). We will engage with government and related NGO and charity bodies (e.g. Defra, HO, EU, NC3Rs, RSPCA), particularly those organizations involved in developing / policing legislation concerning farm animal welfare, through reports, meetings, expert advice on working groups, presentations to relevant bodies, and via contacts already formed through our work for, and advice to, these bodies. The methods developed in this research could be implemented by an integrated DC induction stimulus generator and image analysis software and / or hardware package. If the development of such a package appears feasible, we will liaise with the Bristol University Research and Enterprise Development Dept for advice on IP and commercialisation issues as necessary, and make an application for BBSRC 'follow-on funding'. The timescale of potential commercial benefits from our research is difficult to estimate until the project is in progress and the results become evident. Staff employed on this project already have considerable experience in communicating the impact of their work through interactions with the media, positions on advisory bodies and strategy / review groups, direct contact with the public at scientific exhibitions; personal contacts in governmental, NGO and industry groupings. Further training will be sought (e.g. BBSRC Media Training Course) to expand this skill set.

Committee	Research Committee A (Animal disease, health and welfare)
Research Topics	Animal Health, Animal Welfare, Neuroscience and Behaviour, Technology and Methods Development
Research Priority	X – Research Priority information not available
Research Initiative	X - not in an Initiative
Funding Scheme	X – not Funded via a specific Funding Scheme

I accept the terms and conditions of use (opens in new window)

export PDF file

back to list new search