Animal Welfare
What is Animal Welfare
and How is it Assessed?
42
David Arney
Estonian University of Life Sciences,Tartu, Estonia
Defined by Broom (1986): The welfare of an animal is its
state as regards to its attempts to cope with its environment.
So, what does this mean? Animals have to cope with a
complex environment, such as high temperature, hunger,
fear of predation. Animals have a range of means of coping with these stressors, principally through the adrenal
stress response. This is the same mechanism of response
– the flight or fight response – irrespective of the type of
stressor. Increased respiration rate, heart rate, increased
blood supply to the muscles, erection of hair, pupil dilation. These physiological changes are linked to behavioural responses that ameliorate the stressors: move to a
cooler shaded area, find a food source, escape from the
predator.
Stress is therefore an entirely normal response to
challenges from the environment, and animals are able
to cope with small amounts of stress, and with stressors
from which they can escape. Stress is therefore not necessarily a cause of poor welfare, but distress does have a
negative effect on welfare.
However, the animal may be unable to cope. There
may be no shaded area, no food available, and flight from
the predator may not be possible. The animal’s welfare,
and wellbeing will then be compromised, and this leads
to a chronic stress response, related to raised levels of
cortisol. In this case the animal’s fitness may be reduced,
it may not grow and it may fail to reproduce. We can rank
the state of welfare from poor to good, using a range of
measures, rather than all or nothing.
Measures that are commonly used include:
• Fertility; but some species, notably dogs, can reproduce prolifically in very poor conditions. Indeed,
almost by definition domesticated animals will do so,
as they have been selected to produce large numbers
of offspring in captivity.
• Disease; but this, and the following two on the list, do
not necessarily indicate poor conditions.
• Morbidity.
• Mortality.
• Levels of stress hormones.
• Behavioural indicators; but these may be learnt and
not indicate current welfare conditions.
Individual parameters may be caused by incidental factors, unrelated to the welfare conditions prevailing on an
animal unit. Measurements should be collected to produce a portfolio of evidence rather than reliance on a single measure. The first four of these are simply a matter of
311
Animal Welfare
Figure 42.1. On this farm several cows were observed standing in the
drinking trough.This may have been a means of cooling inflamed hooves.
These were treated and the behaviour ceased. Photo: M. Ots.
record. The capture of stress hormones is made difficult
as the nature of collecting them can itself be stress-inducing. However, residues can be collected from faeces and
saliva as well as directly from blood.
Preferred methods of assessing welfare are behavioural measures, as they are:
•
•
•
•
•
•
Easy to use
Non-invasive
Non-intrusive
Expressions of emotions
Reflect first attempts to cope
More sensitive than injury or disease
Behavioural measures include:
• Abnormal behaviour (Figure 42.1).
• Comparison with normal behaviour (such as time
budgets). The researcher will need to know the normal behaviour profile in order to compare differences
(Figure 42.2).
• Incidents of aggressive behaviour (Figure 42.3)
• Stereotypies: repetitive patterns of behaviour with no
obvious function (Figures 42.4 and 42.5).
• Increased vocalisations
• Choice tests
312
Figure 42.2. Piglets do not normally lie on the sow’s belly. If they do
so this indicates that the sow may have a medical problem. Photo: A.
Pavlenko.
Problems of behavioural measures of stress:
• Not always reliable: some of the abnormal behaviours
may be learnt behaviours resulting from previous
stress events that are no longer extant. Example: cribbiting by a horse may be a learnt behaviour from a
previous stable.
• Human interpretation of the cause or purpose of some
of these behaviours may be inaccurate. We can guess,
but our perception is limited by our human experience.
• Individual animals will respond differently to the
same source of stress. For example, individual
animals have different temperature thresholds, as do
individual humans.
Animal Welfare
Figure 42.3. Tail biting, a common outcome of aggressive behaviour shown by pigs in confined, barren housing conditions. Photo: A.
Pavlenko.
Figure 42.4. Sterotypic behaviour; tongue-rolling shown by a housed
dairy cow. Photo: A. Pavlenko.
• Stereotypies may be a method of coping with stress:
Wiepkema et al. (1987) showed that veal calves performing stereotypies more often had fewer abomasal
ulcers than the other calves.
• The choices offered are relative. They do not indicate
good or poor welfare, only that one of the options
may be better than the other. Both options may be
good or bad for the animal’s welfare.
However, stereotypies are often observed in animals in
poor housing conditions. Broom and Johnson (1993) proposed the following assessment tool (See fact box 1).
Choice tests involve giving animals a choice between
two or more environments or resources, such as offering
dairy cows the choice of entering a cubicle area or a straw
yard. The assumption is that the animal will choose the
option that is in its best interest. Problems with choice
tests include:
Choice tests can be refined to indicate the strength of
preference for one option over another. This can help to
determine whether a resource is a necessity or a luxury.
The less favoured option can be baited with a desirable
resource (often food). The favoured option can be encumbered with difficulty or unpleasantness (the length
of a darkened walkway in the case of the dairy cow, or
the length of a cat urine-soaked walkway in the case of
the laboratory mouse). Animals can be trained to use an
operant device that can be calibrated to altered levels of
work required by the animal to choose one option over
another.
The UK farm animal welfare council suggested five
freedoms that should be satisfied for an animal to be regarded as being in a state of good welfare. These were
first formulated in 1979, principally regarding farm animals, but there is a general consensus of agreement among
animal welfare scientists that they are a useful guide to
assessing the welfare of an animal. The five freedoms remain the basis on which the European Union frames its
animal welfare policy. The five freedoms are:
• The choice may satisfy some transitory need or preference. An animal may make the choice in its shortterm interest at the expense of its long-term interest.
• Individual animals may have individual preferences
not indicative of the group as a whole.
• Choices may change over time: age of the animal,
time of day, stage of reproductive cycle.
• A choice may be preferred, but actually be poor for
welfare: e.g. the choice of a sugar-rich food by rats
does not indicate that these should form the diet of
the housed rat.
313
Animal Welfare
FACT BOX 1
Relationship between stereotypies and animal welfare.
Stereotypies
Welfare
Occasional stereotypies caused
by minor frustration
Very good
Stereotypies for 5% of active time Stereotypies for 40% of active time
Very poor
adapted from Broom and Johnson (1993)
Figure 42.5. Stereotypic behaviour; Nose-pressing shown by a housed
dairy cow. Photo: A. Pavlenko.
1. Freedom from hunger and thirst, access to fresh
water and a diet for full health and vigour.
2. Freedom from discomfort, an appropriate environment with shelter, and comfortable rest areas.
3. Freedom from pain, injury and disease, prevention
or rapid treatment.
4. Freedom from fear and distress, conditions and
treatment which avoid mental suffering.
5. Freedom to express normal behaviour, adequate
space and facilities, company of animal’s own kind.
(European Commission, 2007)
More recently, Bartussek (2001) has proposed an animal
needs index that uses a scoring system for a variety of factors, leading to a sum that is designed to represent a meaningful welfare assessment of housing conditions. There
are five broad sections to this system of assessment:
1. Possibility of mobility
2. Social contact
3. Condition of flooring
4. Stable climate (including light and noise)
5. Quality of stockman’s care
314
However, this system does not seem to have been adopted
much outside its native Austria.
There is a method for determining the priorities of
animals for resources through measuring their motivation
for access to the resources. The concept is derived from
human behaviour expressed by the economic theory of
demand function (Dawkins, 1983; Hursh, 1984). In the
context of animal behaviour, ‘cost’ is the amount of time
spent on an activity or work the animal is prepared to
do to achieve the resource. For example; rats pushing a
lever or chickens or mink pushing through an increasingly weighted gate to access nesting material. This demand may be described as elastic if the animal adjusts
the price it is prepared to pay for differing quantities of
the resource, such as space. As the amount of work, or
cost, increases, the animal becomes less prepared to pay
the cost in order to achieve the resource. Plotting the outcomes on a logarithmic scale produces a straight line,
the demand function. Resources producing this kind of
response are typically described as luxury resources. In
contrast, an inelastic demand is for an essential resource,
such as food. Changing the amount of work the animal
has to do to achieve an essential resource has little effect – the price will continue to be paid. In addition, the
expenditure an animal is prepared to make, in amount of
time or work, can be used to rank the importance of a
range of resources. The steepness of the demand function
gradient indicates the degree of motivation. The resource
may be the opportunity to perform a behavioural activ-
Animal Welfare
ity, such as digging, swimming or even rest. Criticisms
of this method include: the artificial nature of the test,
the influence of prior deprivation, prior experience and
external factors, including the time of day.
Conclusions
The welfare of animals concerns not simply stress, experienced by an animal, but its ability to manage stress,
whether it be physical or mental stress. Animals in the
wild and in captivity are exposed to many and varied
stressors. If the stressor continues despite an animal’s efforts to remove it, we can consider the animal to be in
a poor state of welfare. Welfare can be ranked; there is
not simply good or bad welfare, but many gradations of
wellbeing. We can measure and record many factors that
can indicate poor or good welfare, and the more measures we take the more likely we are to make an accurate
assessment. Behavioural measures are particularly good
as they are, among other things, relatively easy to use,
are (or ought to be) non-intrusive, show an animal’s first
responses to cope and are sensitive. However, caution
should be used with such measures as they can be misleading to a human observer. Stereotypies can also indicate poor welfare, and particularly a poor environment.
Letting an animal choose from options, using a choice
test, can give us clues as to the relative preference of the
options offered, and this can be refined to include positive and negative outcomes to assess the strength of preference of one option over another. The five freedoms are
an enduring guide to the assessment of welfare, but other
systems are also in use. An index system of scoring welfare factors and deriving an overall index of welfare has
been developed, though there is some doubt as to whether
an animal’s welfare can be adequately expressed by a single number.
315
References
Frank, B., Persson, M. and Gustafsson G. 2002. Feeding dairy cows for
decreased ammonia emission. In: Livestock Production Science. 76,
pp. 171 – 179.
Reynal, S.M. and Broderick, G.A. 2005. Effect of Dietary Level on
Rumen-Degraded Protein on Production and Nitrogen Metabolism
in Lactating Dairy Cows. In: J. Dairy Sci. 88, pp. 4045 – 4064.
Steinfeld, H., Gerber, P., Wassenaar, T., Castel, V., Rosales, M. and de
Haan, C. 2006. Livestock’s long shadow. Environmental issues and
options. http://www.virtualcentre.org/en/library/key_pub/longshad/
A0701E00.pdf
Swensson, C. 2003. Relationship between content of crude protein in
rations for dairy cows, N in urine and ammonia release. In: Livestock
Production Science. 84, pp. 125 – 133.
van Duinkerken, G., Andre, G., Smits, M.C.J., Monteny, G.J. and
Šebek, L.B.J. 2005. Effect of Rumen-Degradable Protein Balance
and Forage Type on Bulk Milk Urea Concentration and Emission
of Ammonia from dairy Cow Houses. In: J. Dairy Sci. 88, pp. 1099
– 1112.
Chapter 42
Bartussek, H. 2001. An historical account of the development of the animal needs index ANI-35L as part of the attempt to promote and regulate farm animal welfare in Austria. An example of the interaction
between animal welfare science and society. In: Acta Agriculturae
Scandinavica A, vol. 51, suppl. 30, pp.34-41
Broom, D.M. 1986. Indicators of poor welfare. In: British Veterinary
Journal. Vol. 142, pp. 524–526.
Broom, D. and Johnson, K.G. 1993. Approaching questions of stress
and welfare. In: Stress and animal welfare. Kluwer Academic
Publishers, pp 1-7.
Dawkins, M.S. 1983. Battery hens name their price: consumer demand
theory and the measurement of ethological ‘needs’. In: Anim. Behav.
31, pp. 1195–1205
European Commission 2007. Animal welfare factsheet. DirectorGeneral for Health and Consumer Protection.
Hursh, S.R. 1984. Behavioural Economics. In: J. Exp. Anal. Behav. 42,
pp. 435–452.
Wiepkema, P.R., Van Hellemond, K.K., Roessingh, P. and Romberg, H.
1987. Behaviour and abomasal damage in individual veal calves. In:
Applied Animal Behaviour Science. Vol. 18, p.257.
Further reading
Appleby and Hughes 1997. Animal welfare.
Benson and Rollin 2004. The well-being of farm animals
Broom and Fraser 2003. Domestic animal welfare and behaviour. 4th
edition
Martin and Bateson 1993. Measuring behaviour.
The following journals:
Animal Welfare, Applied Animal Behaviour Science, Animal.
490
Chapter 43
Alcaro, A., Huber, R. and Panksepp, J. 2007. Behavioral functions of
the mesolimbic dopaminergic system: An affective neuroethological perspective. In: Brain Research Reviews, 56: 283-321.
Burghardt, G.M. 2005. The genesis of animal play. Cambridge, MA:
MIT Press.
Nelson, E.E. and Panksepp, J. 1998 Brain substrates of infant-mother
attachment: Contributions of opioids, oxytocin, and norepinephrine.
In: Neuroscience & Biobehavioral Reviews, 22: 437-452.
Numan, M. and Insel, T.R. 2003. The neurobiology of parental behavior. New York: Springer-Verlag.
Panksepp, J. 1990. The psychoneurology of fear: Evolutionary perspectives and the role of animal models in understanding human anxiety. In: Roth, M., Burrows, G.D. and Noyes, R. (eds) Handbook of
anxiety. pp. 3-58 Amsterdam Elsevier/North-Holland: Biomedical
Press.
Panksepp, J. 1998. Affective neuroscience: The foundations of human
and animal emotions. New York: Oxford University Press.
Panksepp, J. 2007. Can PLAY diminish ADHD and facilitate the construction of the social brain. In: Journal of the Canadian Academy
of Child and Adolescent Psychiatry, 10: 57-66.
Panksepp, J., Fuchs, T., and Iacabucci, P. 2010. The basic neuroscience
of emotional experiences in mammals: The Case of subcortical
FEAR circuitry and implications for clinical anxiety. In: Applied
Animal Behaviour Science, in press.
Panksepp, J. and Moskal, J. 2008. Dopamine and SEEKING: Subcortical
‘reward’ systems and appetitive urges. In: Elliot, A. (ed.) Handbook
of approach and avoidance motivation, pp. 67-87 Mahwah, NJ.:
Lawrence Erlbaum Associates,
Panksepp, J. and Zellner, M. 2004. Towards a neurobiologically
based unified theory of aggression. In: Revue Internationale de
Psychologie Sociale/International Review of Social Psychology. 17,
pp. 37-61.
Pellis and Pellis 2009. The playful brain: Venturing to the limits of neuroscience. Oxford, UK: Oneworld Pubs.
Pfaff, D.W. 1999. Drive: Neurobiological and molecular mechanisms
of sexual behavior. Cambridge, MA: MIT Press.
Siegel, A. 2005. The neurobiology of aggression and rage. Boca Raton,
FL: CRC Press.
Watt, D.F. and Panksepp, J. 2009. Depression: an evolutionarily conserved mechanism to terminate separation-distress? A review
of aminergic, peptidergic, and neural network perspectives. In:
Neuropsychoanalysis, 11, pp. 5-104.
Further Reading
McMillan, F. (ed.). 2003. Mental Health and Well-being in Animals.
Ames, Iowa: Iowa State University Press.
Panksepp, J. 2003. At the interface of affective, behavioral and cognitive neurosciences: Decoding the emotional feelings of the brain. In:
Brain and Cognition, 52, 4-14.
Panksepp, J. 2005. Affective consciousness: Core emotional feelings in
animals and humans. In: Consciousness & Cognition, 14, 30-80.
Panksepp, J. 2006. Emotional endophenotypes in evolutionary psychiatry. In: Progress in Neuro-Psychopharmacology & Biological
Psychiatry, 30, 774-784.