What is scientific assessment of welfare?

There has been a dramatic increase in society’s interest in the welfare of farm animals (Fraser, 2001; Levy, 2004; Coleman, 2008) and consequently there has been increased scrutiny of the use of farm animals. While consumer and public attitudes to animal welfare are likely to be influential in determining society’s use of farm animals, science has a critical role in underpinning governments’ decisions, on behalf of the community, on farm animal use, and the attendant conditions and compromises.

Many people are unaware of the factual information regarding the conditions under which farm animals live, how they are treated and their species-specific requirements. Furthermore, failure to assure consumers, the general public, governments, special interest groups and retailers that the welfare standards for farm animals are underpinned by sound science may risk the adoption of new technology in the animal industries that could affect the profitability and viability of these industries by affecting specific animal uses (Hemsworth et al., 2007). Thus, scientific information on how animals adapt or respond to farming practices needs to be disseminated to the general public. The exclusion of science from the welfare discussion will result in emotive arguments from sectional interests dominating community discussion. This is not to say that people’s emotional responses are not relevant to the discussion. Indeed, such responses partly reflect current community values, however, they should contribute to, not preempt, the discussion. Alternatively, when research demonstrates that welfare is at risk, the livestock industries need to proactively respond by making the necessary changes in much the same way as they would adopt new technologies to improve health, nutrition and productivity (Hemsworth et al., 2007).

While science and community values underpin the establishment, amendment or validation of industry welfare standards and practices, an understanding by industry of the basis of these standards and practices, particularly their scientific basis, is important for industry personnel to appreciate the need for improvements in animal welfare standards and practice and to achieve these improvements. Furthermore, as mentioned above, improved welfare in many cases may lead to improved individual animal productivity (Hemsworth and Coleman, 1998) since an important focus in improving animal welfare is reducing housing, husbandry and handling stress.

Background – The Problem

A current weakness in studying animal welfare is that there are differing definitions of animal welfare (Fraser, 2003; Sandoe et al., 2004). This unease with the definition exists both within science and more broadly when decisions on acceptable welfare standards are being made by individuals or the community. There are three prominent concepts of animal welfare in the literature leading to the welfare of animals being judged on the basis of: 1. how well the animal is performing from a biological functioning perspective; 2. affective states, such as suffering, pain and other feelings or emotions; and 3. the expression of normal or ‘natural’ behaviours. The so-called ‘five freedoms’, that is freedom from hunger and thirst, from discomfort, from pain, injury and disease, to express normal behaviour, and from fear and distress (FAWC, 1993) include aspects of all of the above three concepts of animal welfare. While most would accept that these freedoms are necessary to avoid a lack of suffering, in terms of a consensus on animal welfare assessment there has been little attempt to define the levels of freedom that are desirable together with the adverse consequences of not providing such freedoms (Barnett and Hemsworth, 2009).

The first concept, which is often called the ‘biological functioning’ concept, equates poor welfare to biological dysfunction (Broom and Johnson, 1993; Hemsworth and Coleman, 1998), and thus a broad examination of the behavioural, physiological, health and fitness responses of animals are measured to judge animal welfare. The second concept, often called the ‘affective state’ or ‘feelings-based’ concept, defines animal welfare in terms of emotions and emphasises reductions in negative emotions, such as pain and fear and frustration, and increases in positive emotions such as comfort and pleasure (Fraser, 2003). This affective state concept has been promoted on the basis that animal welfare ultimately concerns animal feelings or emotions (Duncan, 2004). Measuring preferences of animals, using for example preference tests, has been used by scientists to assess animal welfare predominantly on the view that these preferences may be influenced by the animal’s emotions. While not well enunciated, the third concept promotes the principle that animals should be allowed to express their normal behaviour (Barnett and Hemsworth, 2009). This ‘normal behaviour’ concept probably has the least credibility in science. For example, there is broad agreement within science that it is often difficult to attribute actual suffering when the expression of certain behaviours is prevented or is absent when it would be expected to be present (Dawkins, 2003). Furthermore, as discussed by a number of authors, ‘wild’ behaviour may represent an animal’s efforts to survive in a life and death struggle or contest and therefore some ‘natural’ responses are adaptations to cope with extreme adverse situations.

What’s new – How to get to the solution

This uncertainty surrounding the concept of animal welfare and how animal welfare should be assessed does not necessarily diminish the robustness of the research utilising methodologies or measurements arising from these views or concepts of animal welfare.

As reviewed by Barnett and Hemsworth (2009), there are several commonalities in the rationale for these approaches. For example, it is considered that animals will be motivated to choose those resources or behaviours that maintain homoeostasis or biological functioning to optimise their fitness; that is, optimise their growth, reproduction, injury status, health, and survival. Furthermore, feelings or subjective affective states have evolved to motivate behaviour to meet needs that have to be satisfied in order for the organism to survive, grow, and reproduce. This conceptual convergence suggests an opportunity to develop a broader consensus on the study of animal welfare by reducing both conceptual differences and consequently methodological differences in animal welfare science.

The validity of the welfare criteria can be tested in two predominant ways (Barnett and Hemsworth, 2009). Research has found that there are correlations between independent measures of different concepts of animal welfare, and it has also been shown that an intuitively aversive condition reduces animal welfare on the basis of the measures of different concepts of animal welfare. Therefore, research examining the validity of these concepts and methodologies, is necessary to understand the relationships between the different animal welfare concepts, which will ultimately minimise the actual conceptual and methodological differences as discussed above.


Science has a clear contribution to make in forging better agreement on animal welfare assessment and in developing practical animal-based measures of animal welfare. Good scientific research provides a means of assessing the actual impact of housing, husbandry and handling threats to the welfare of poultry, however this research is far from complete, and the conclusions drawn on the welfare of animals are presently reliant on the approach that the researcher uses to assess welfare. What is lacking is a good understanding of how these different approaches to welfare assessment relate to one another.

The development of a broader scientific consensus on welfare measures arising from this research should lead to the development of credible measures that can be incorporated into welfare assessment and screening tools in the field.

Call for action

Please refer to the resources on Poultry Hub for more information on this topic and the Poultry CRC’s research in this area. Furthermore, a recent review titled “Welfare issues and housing for laying hens: international developments and perspectives” on Australian Eggs website provides a good overview of the science on the welfare of laying hens.


Barnett, J.L. and Hemsworth, P.H. (2009). Welfare monitoring schemes: using research to safeguard welfare of animals on the farm. Journal of Animal Welfare Science 12, 1–17.

Broom, D. M., and Johnson, K. G. (1993). Stress and Animal Welfare. 1st Edition. Chapman and Hall, London, UK.

Coleman, G. (2008). Public perceptions of animal pain and animal welfare. OIE Technical Series 10, 26-37.

Dawkins, M. S. (2003). Behaviour as a tool in the assessment of animal welfare. Zoology 106, 383-387.

Duncan, I. J. H. (2004). A concept of welfare based on feelings. In The Well-being of Farm Animals: Challenges and Solutions, editors G. J. Benson, and Rollin, B. E. Blackwell Publishing, Iowa, USA, pp 95-101.

FAWC (Farm Animal Welfare Council). 2003. Second Report on Priorities for Research and Development in Farm Animal Welfare.

Fraser D 2001 Farm animal production: changing agriculture in a changing culture. Journal of Applied Animal Welfare 4, 175-190

Fraser, D. 2003. Assessing animal welfare at the farm and group level: the interplay of science and values. Animal Welfare 12, 433-443.

Hemsworth, P.H. and Coleman, G.J. (1998) Human-Livestock Interactions: The Stockperson and the Productivity and Welfare of Intensively-farmed Animals. CAB International, Oxon UK.

Hemsworth, P.H. Barnett, J.L., Rickard, M and Coleman, G.J. (2007). Australia’s research and development capacity in animal welfare. Farm Policy Journal 4 (4, November Quarter 2007), 23-31.

Levy, N. (2004). What Makes Us Moral? Crossing the Boundaries of Biology. Oneworld, Oxford, UK.

Sandøe, P., Forkman, F. and Christiansen, S. B. (2004). Scientific uncertainty – how should it be handled in relation to scientific advice regarding animal welfare issues? Animal Welfare 13, 121-126.