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Scientific reports2020; 10(1); 21409; doi: 10.1038/s41598-020-78386-z

Blink rate as a measure of stress and attention in the domestic horse (Equus caballus).

Abstract: Measuring animal stress is fundamentally important for assessing animal emotional state and welfare. Conventional methods of quantifying stress (cortisol levels, heart rate/heart rate variability) require specialist equipment and are not instantly available. Spontaneous blink rate (SBR) has previously been used to measure stress responses in humans and may provide a non-invasive method for measuring stress in other animal species. Here we investigated the use of SBR as a measure of stress in the domestic horse. SBR was measured before and during a low-stress event (sham clipping) and compared with heart rate variability and salivary cortisol. For the entire sample, there was a reduction in SBR (startle response) during the first minute of clipping. For horses reactive to clipping, the initial reduction in SBR was followed by an increase above baseline whereas the SBR of the non-reactive horses quickly returned to baseline. For the entire sample, SBR correlated with heart rate variability and salivary cortisol. We have demonstrated that SBR is a valid fast alternative measure of stress in horses, but the initial 'startle' response must be considered when using this parameter as a measure of animal stress.
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Publication Date: 2020-12-08 PubMed ID: 33293559PubMed Central: PMC7722727DOI: 10.1038/s41598-020-78386-zGoogle Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research article studies the use of spontaneous blink rate (SBR) as a measure of stress in domestic horses, indicating that it can serve as a fast, non-invasive alternative to conventional stress measurement methods like heart rate variability and salivary cortisol.

Objective and Methodology

  • The research set out to explore the value of spontaneous blink rate (SBR) in evaluating stress levels in horses, as an alternative to conventional, equipment-heavy methods like monitoring heart rate and cortisol levels which are not immediate.
  • Traditionally used in humans, SBR is hoped to be an effective, non-invasive method for measuring stress in other animal species.
  • The researchers measured the blink rate in horses before and during a low-stress event (sham clipping) and compared these results with previously established indicators such as heart rate variability and salivary cortisol levels.

Findings

  • The study found that for all horses, the blink rate (indicative of a startle response) dropped during the first minute of the clipping event.
  • For horses that reacted negatively to clipping, this initial drop in SBR was followed by an upsurge above the baseline. On the other hand, non-reactive horses’ SBR quickly returned to baseline levels.
  • Upon comparing with heart rate variability and salivary cortisol, SBR showed a correlation for the entire sample of horses.

Conclusions

  • The research proved that SBR could indeed serve as a valid, quick substitute for assessing stress in horses, adding to the repertoire of stress measurement tools available for assessing animal welfare.
  • However, the study also notes that the initial ‘startle’ response (the dip in SBR at the start of a low-stress event) needs to be taken into account when using this parameter as a measure of animal stress.

Cite This Article

APA
Mott RO, Hawthorne SJ, McBride SD. (2020). Blink rate as a measure of stress and attention in the domestic horse (Equus caballus). Sci Rep, 10(1), 21409. https://doi.org/10.1038/s41598-020-78386-z

Publication

Scientific reports
ISSN: 2045-2322
NlmUniqueID: 101563288
Country: England
Language: English
Volume: 10
Issue: 1
Pages: 21409
PII: 21409

Researcher Affiliations

Mott, Richard O
  • The Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Midlothian, UK. Richard.Mott@glasgow.ac.uk.
Hawthorne, Susan J
  • School of Pharmacy and Pharmaceutical Sciences, Ulster University, Coleraine, Co. Londonderry, UK.
McBride, Sebastian D
  • Aberystwyth University, Penglais, Aberystwyth, Ceredigion, UK.

MeSH Terms

  • Animals
  • Attention / physiology
  • Behavior, Animal / physiology
  • Blinking
  • Horses
  • Hydrocortisone / analysis
  • Models, Animal
  • Saliva / chemistry
  • Stress, Psychological / diagnosis
  • Stress, Psychological / metabolism
  • Stress, Psychological / physiopathology

Grant Funding

  • Biotechnology and Biological Sciences Research Council

Conflict of Interest Statement

The authors declare no competing interests.

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