How Studying Interactions Between Animal Emotions, Cognition, and Personality Can Contribute to Improve Farm - Genetics and the Behavior of Domestic Animals - page 102

well-being and not merely the absence of disease or infirmity, 1 it is essential
to reconsider the management of animal health through an integrated view,
particularly by taking into consideration animal emotions and welfare/stress.
There are permanent interactions between the immune system and the
brain, notably through the inflammatory cytokines and the autonomic
nervous and neuroendocrine systems. Although research in this area is
recent, there is evidence that chronic stress results in glucocorticoid receptor
resistance that induces exaggerated local release of inflammatory cytokines,
resulting in increased disease risk because inflammation plays an important
role in the onset and progression of a wide range of diseases (for a review,
see Cohen et al., 2012 ). Likewise, there is evidence in humans showing that,
in contrast, experiencing positive emotions may improve health. Pioneering
researchers suggest that there are health benefits in humans of humor and
laughter as positive-emotions promoters, especially in coping with a diagno-
sis of cancer ( Mahony et al., 2002 ). Although the scientific evidence for this
claim is inconclusive ( Martin, 2001 ), humor is being increasingly used as a
mean of reducing stress and making patients feel better ( Penson et al.,
2005 ). Obviously, there are no such studies in animals. Nevertheless, an
increase in stress responses is often associated with an increased vulnera-
bility to infectious, metabolic, and production diseases. It is logical to sug-
gest, therefore, that giving increased opportunities for positive experiences
might also have a positive effect on animal health. For instance, pigs
given the opportunity to show successful adaptation by rewarded cognitive
processes (i.e. cognitive enrichment) express a higher immune reactivity
and recover more quickly from a standard biopsy ( Ernst et al., 2006 ).
Although psychological factors influence the immune system at any point
in the life-span, it has been shown in laboratory animals that the immatu-
rity of a young infant's immune responses makes it more vulnerable, espe-
cially during the fetal and neonatal stages ( Coe and Lubach, 2003 ).
Various studies in humans show clearly that perinatal stress has a pro-
gramming effect resulting in vulnerability to the development of chronic
diseases in adulthood ( Lupien et al., 2009 ). We can therefore hypothesize
that proper welfare management of the young animal (either directly after
birth or throughout the welfare state of the dam before birth) would
improve its ability to cope with various forms of health challenges
encountered not only during early postnatal life but also during its whole
production life.
Although relatively recent, the concept of cognitive enrichment based on
the evaluative abilities of the animals, allows defining behavioral strategies
that have the potential to sustainably improve animal welfare and maybe
health. Such behavioral strategies such as animal-friendly housing should be
1. World Health Organization ( https://apps.who.int/aboutwho/en/definition.html ).