How Studying Interactions Between Animal Emotions, Cognition, and Personality Can Contribute to Improve Farm - Genetics and the Behavior of Domestic Animals - page 86

the 1970s onwards ( Forkman et al.,2007 ) though the designs were generally
modified to suit the circumstances. Fear of novelty is evaluated using the
open-field test or exposure to a novel object while few specific tests have
been developed to assess an animal's fear of humans, such as the forced
approach test or the voluntary approach test. The forced approach test is more
likely to elicit an active response whereas the likelihood of observing either no
response or a passive one is greater in the voluntary approach test ( Waiblinger
et al.,2006 ). Restraint tests are also commonly used, for example by restrain-
ing the animal in a chute or, more commonly, by inducing a tonic immobility
reaction ( Forkman et al.,2007 ). Finally, fear can be induced and evaluated
in terms of the animals' reactions when exposed either to a natural predator,
or to a sudden event (i.e. startle test), or to a signal that had been previously
associated with a nociceptive event such as electric shock (i.e. conditioned
fear test).

A Need for a Refined and Structured Methodology
in Fear Studies
Many tests of fear were originally designed for laboratory rodents and,
unfortunately, several of these have been used for farm animals with insuffi-
cient regard for their biological relevance. For example, while laboratory
rodents are nocturnal and wall-seeking (wild rats build and live in burrows)
most farm animals are diurnal and, apart from poultry, their ancestors gener-
ally occupied open areas/ranges. Cattle may actually perceive the open-field
test as an enclosed area. Furthermore, most farm animals are highly gregari-
ous and react heavily to being separated from group-mates, many have exclu-
sive mother

young relationships and the young are generally precocious. In
view of such species differences in ecological experience and motivation we
must avoid testing animals in inappropriate environments that may elicit moti-
vational states unrelated to the one under study, thereby leading to inaccurate
estimations of fear and inconsistencies between studies. Reconsideration of the
ecological contexts of domestic species may help us develop more reliable and
valid tests and measures of fear.
Despite these cautionary notes, studies of laboratory animals may still
guide the interpretation of a range of emotional reactions observed when
farm animals are exposed to aversive situations. From an ecological perspec-
tive, suddenness and novelty, which underpin many fear tests ( Boissy, 1998 ),
are key features of predatory attack and we must remember that domestic
ungulates and poultry kept free-range may still experience predation by wild
animals and dogs ( Shelton and Wade, 1979 ). The ability to cope with an
aversive event can also strongly influence the animal's emotional experience.
For instance, cows with the strongest tendency to approach a novel object
voluntarily are also the most reactive to humans, but the opposite is true
if they are forced to move toward that novel object ( Murphey et al., 1981 ).