State of the art on daily rhythms of physiology and behaviour in horses

Abstract

This article reviews the literature on the daily rhythm in horses. Many physiological processes have been studied in horses to investigate their daily rhythmicity. In horses many rhythms are driven by an endogenous pacemaker, some of them endogenously generated, others influenced by external stimuli. It then addresses the influence of maturation and ageing, physical exercise and jet lag on these rhythms. The study of daily rhythms in horses is of considerable importance in all aspects of horse management to maintain the natural physiological behaviours of this species, necessary to guarantee the good welfare in breeding and athlete horses. Chronophysiology in horses also has clinical implications, it can influence disease occurrence, diagnostic tests and the effect of medical treatments.

Equine Activity Time Budgets: The Effect of Housing and Management Conditions on Geriatric Horses and Horses with Chronic Orthopaedic Disease

“…The significant difference in movement time budgets and activity count between seasons (tracking rounds), with substantially higher values during the summer months, supports the association between movement counts and pest defence, which was also observed in free-ranging Camargue horses during the summer [24]. In accordance with the literature [6,21,28,59,65,[67][68][69][70][71][72][73], movement in the present study occurred mostly during day-time hours and least at night; however, activity peaks could be observed just prior to morning feeding in horses kept on restricted feeding and non-edible bedding (farm 1), which may be linked to anticipatory behaviour or stressful feeding times [57,58].…”

“…The time budget for movement is influenced by different stabling conditions and feeding schedules and considered a reliable indicator of equine welfare [6,17,21,28,59,65,[67][68][69][70][71][72][73]. Horses living under inappropriate environmental conditions, including insufficient forage opportunities, high stocking densities and small enclosures, increased their active locomotion patterns [6,17,21,28,59,65,[67][68][69][70][71][72][73]. In addition, domestic mares kept in stalls for 72 h exhibited higher levels of movement during subsequent turn-out than mares kept on pasture with conspecifics [6,72].…”

Influences of age and sex on leukocytes of healthy horses and their ex vivo cytokine release

“…When using blood cell morphometric parameters and cytokine production as biomarkers for health and disease or to monitor response to treatment, it is necessary to identify the variables affecting these parameters in healthy animals (Schuberth et al, 2001) and to prove whether diurnality must be considered for comparisons (Piccione and Giannetto, 2011;Benito et al, 2014).…”