Adrenergic Tone as an Intermediary in the Temperament Syndrome Associated With Flight Speed in Beef Cattle

Abstract

The temperament of farm animals can influence their resilience to everyday variations within the managed production environment and has been under strong direct and indirect selection during the course of domestication. A prominent objective measure used for assessing temperament in beef cattle is the behavioral flight response to release from confinement in a crush or chute. This behavioral measure, termed flight speed (also known as escape velocity) is associated with physiological processes including body temperature, feeding behavior, growth rate, carcass composition, immune function, and health outcomes. This review examines the functional links between this suite of traits and adrenergic activity of the sympathetic nervous system and the adrenomedullary hormonal system. It is suggested that flight speed is the behavioral aspect of an underlying “flightiness” temperament syndrome, and that elevated adrenergic tone in animals with a high level of flightiness (i.e., flighty animals) tunes physiological activities toward a sustained “fight or flight” defense profile that reduces productivity and the capacity to flourish within the production environment. Nonetheless, despite a common influence of adrenergic tone on this suite of traits, variation in each trait is also influenced by other regulatory pathways and by the capacity of tissues to respond to a range of modulators in addition to adrenergic stimuli. It is suggested that tuning by adrenergic tone is an example of homeorhetic regulation that can help account for the persistent expression of behavioral and somatic traits associated with the flight speed temperament syndrome across the life of the animal. At a population level, temperament may modulate ecological fit within and across generations in the face of environmental variability and change. Associations of flight speed with the psychological affective state of the animal, and implications for welfare are also considered. The review will help advance understanding of the developmental biology and physiological regulation of temperament syndromes.

Competence to thrive: resilience as an indicator of positive health and positive welfare in animals

“…Such studies contribute to the ongoing refinement of the general concept of temperament and methods for its assessment, and enable application of the general concept and the specific tests to questions such as the influence of affective state on performance in the tests and conversely, the utility of the tests to measure affective state when performance is conditioned on temperament scores (Kremer et al 2021). Ongoing interpretation of the relationships between behaviours, physiology, immune function and performance support refinement of the causal model of temperament to the concept of temperament as a distributed network property embedded in physiological, immunological and performance functions as well as in behaviour (Colditz 2021): a model no doubt requiring further refinement. The distributed/embedded model suggests that measurement of the underlying temperament trait might be improved by measurements made on each dimension rather than by measurements solely of behaviour, a proposition supported by studies on body temperature and blood lactate as predictors of temperament in cattle (Williams et al 2019).…”

“…In this view, attributes like fear and temperament (and resilience as discussed below) are not substantive entities that can act like an extra hand to manipulate yet other entities such as cognition, immune function, behaviour or energy metabolism. Rather, attributes like fear and temperament are distributed properties realised through activity within sub-cellular, cellular, organ and whole-body processes (Baffy and Loscalzo 2014;Guyon et al 2017;Scheffer et al 2018;Colditz 2021).…”

Competence to thrive: resilience as an indicator of positive health and positive welfare in animals

“…Such studies contribute to the ongoing refinement of the general concept of temperament and methods for its assessment, and enable application of the general concept and the specific tests to questions, such as the influence of affective state on performance in the tests and, conversely, the utility of the tests to measure affective state when performance is conditioned on temperament scores (Kremer et al 2021). Ongoing interpretation of the relationships among behaviours, physiology, immune function and performance support refinement of the causal model of temperament to the concept of temperament as a distributed network property embedded in physiological, immunological and performance functions as well as in behaviour (Colditz 2021)…”

“…In this view, attributes such as fear and temperament (and resilience, as discussed below) are not substantive entities that can act like an extra hand to manipulate yet other entities such as cognition, immune function, behaviour or energy metabolism. Rather, attributes such as fear and temperament are distributed properties realised through activity within subcellular, cellular, organ and whole-body processes(Baffy and Loscalzo 2014;Guyon et al 2017;Scheffer et al 2018;Colditz 2021).…”

A biological integrity framework for describing animal welfare and wellbeing

“…Across the study period, pigs from the enriched environment had lower variance in body weight than conventionally raised pigs. In view of the prominent roles of cortisol and autonomic tone (indicated by heart rate and heart rate variability) in modulating the moment-to-moment utilization of energy (Mormède et al 2011;Colditz 2021) and the occurrence of persistent variation between individuals in autonomic tone (Koolhaas et al 1999;Koolhaas 2008;Colditz 2021), further studies on links between stress resilience, the dynamics of energy utilization and uniformity of daily performance seem warranted. Together these results suggest that uniformity of the growth trajectory that is interpreted as a resilience indicator in structural analyses is linked with an improved capacity to cope with a range of experimental stressors.…”