FREE SHIPPING over $40
OVER 9000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Home / Equine Research Bank / PLoS One / Horse behavior and facial movements in relation to food rewa...
PloS one2023; 18(6); e0286045; doi: 10.1371/journal.pone.0286045

Horse behavior and facial movements in relation to food rewards.

Abstract: Food rewards are believed to have a positive valence in horses. The aim of this study was to assess the effect of food rewards on horse behavior before entering a horse chute, and behavior and facial movements while restrained in it. Thirteen female adult horses were brought once daily to an animal handling facility for three weeks. In week 1, baseline period, no reinforcement was applied. In weeks 2 and 3, experimental phase, half of the horses received positive reinforcement treatment after entering and remaining in the chute; the remaining horses were considered as controls (no positive reinforcement applied). There was a cross-over between the groups during the experimental phase. Horses were individually brought to the restraining chute and videos recorded during 60-sec. The duration and number of entries into the area close to the gate leading to the chute were measured before restraining and body posture, neck position, and tail swinging were recorded in the chute. Facial movements were also recorded and scored using EquiFACS methodology. Multilevel linear and logistic models were built to assess behavioral changes from baseline to the treatment phase and between phases (control and positively reinforced). Horses did not change their body posture or tail swings across the different phases (P > 0.1) and were less likely to show lowered neck during the positively reinforced phase (OR: 0.05; CI95%: 0.00-0.56; P = 0.05) compared to baseline. The likelihood of a lowered neck did not differ between the positive reinforcement and control phases (P = 0.11). In the positively reinforced phase, horses seemed to be more attentive (ears forward) and active (less eye closures, more nose movements) than in the control phase. A three-day positive reinforcement phase did not elicit major changes in body behavior in the chute but affected the facial movements of group-housed mares.
Copyright: © 2023 Carmo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Get Full Text
Publication Date: 2023-06-12 PubMed ID: 37307268PubMed Central: PMC10259797DOI: 10.1371/journal.pone.0286045Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
LinkedInCopy
  • Journal Article

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 paper explores the impact of food rewards on horse behavior and facial movements. It found that positive reinforcement didn’t significantly alter their physical behavior, but it did cause noticeable changes in their facial expressions.

Objective and Methodology

  • The goal of the study was to assess the impact of food rewards on horse behavior and facial movements, particularly before entering an enclosure (a chute), and during confinement within it.
  • Thirteen adult female horses were used in the experiment, which spanned three weeks. The horses were divided into two groups: a control group that received no rewards, and a test group that was positively reinforced with food after entering the chute.
  • The first week served as the neutral period wherein no reinforcements were given, while the second and third weeks constituted the experimental phase in which food rewards were administered. There was a cross-over between the two groups during the experimental phase.
  • Horses’ body postures, neck positions, tail swings, and facial movements were analyzed and recorded using videos captured during 60-second periods.
  • The researchers applied the EquiFACS methodology to score the facial movements of the horses.
  • The researchers used multilevel linear and logistic models to evaluate behavioral changes from the initial stage to the treatment phase and across the different phases.

Findings

  • The researchers found no significant alteration in body posture or tail swings across the different phases of the study.
  • However, horses displayed less likelihood of showing lowered neck during the positively reinforced stage compared to the baseline period.
  • The chance of a lowered neck did not vary noticeably between the positive reinforcement and control phases.
  • During the positive reinforcement stage, horses appeared to be more aware and active, indicated by more forward ear movements, lesser eye closures, and more nose movements than in the control phase.
  • Although the three-day positive reinforcement phase did not incite significant changes in body behavior in the chute, it effected visible changes in the facial movements of the group-housed mares.

Conclusion

  • The research indicates that while food rewards (positive reinforcement) do not significantly affect horses’ body behavior, they do influence facial movements, making horses more attentive and active.
  • Such findings could be beneficial in further understanding horse behavior, especially in response to positive reinforcement.

Cite This Article

APA
Carmo LG, Werner LC, Michelotto PV, Daros RR. (2023). Horse behavior and facial movements in relation to food rewards. PLoS One, 18(6), e0286045. https://doi.org/10.1371/journal.pone.0286045

Publication

PloS one
ISSN: 1932-6203
NlmUniqueID: 101285081
Country: United States
Language: English
Volume: 18
Issue: 6
Pages: e0286045
PII: e0286045

Researcher Affiliations

Carmo, Laize G
  • Graduate Program in Animal Science, School of Medicine and Life Sciences, Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil.
Werner, Laís C
  • Graduate Program in Animal Science, School of Medicine and Life Sciences, Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil.
Michelotto, Pedro V
  • Graduate Program in Animal Science, School of Medicine and Life Sciences, Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil.
Daros, Ruan R
  • Graduate Program in Animal Science, School of Medicine and Life Sciences, Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil.

MeSH Terms

  • Female
  • Horses
  • Animals
  • Reward
  • Movement
  • Face
  • Reinforcement, Psychology
  • Posture

Conflict of Interest Statement

The authors have declared that no competing interests exist.

References

This article includes 36 references
  1. Mellor DJ. Updating Animal Welfare Thinking: Moving beyond the "Five Freedoms" towards "A Life Worth Living".. Animals (Basel) 2016 Mar 14;6(3).
    doi: 10.3390/ani6030021pmc: PMC4810049pubmed: 27102171google scholar: lookup
  2. Boissy A, Manteuffel G, Jensen MB, Moe RO, Spruijt B, Keeling LJ, Winckler C, Forkman B, Dimitrov I, Langbein J, Bakken M, Veissier I, Aubert A. Assessment of positive emotions in animals to improve their welfare.. Physiol Behav 2007 Oct 22;92(3):375-97.
    doi: 10.1016/j.physbeh.2007.02.003pubmed: 17428510google scholar: lookup
  3. Rault JL, Hintze S, Camerlink I, Yee JR. Positive Welfare and the Like: Distinct Views and a Proposed Framework.. Front Vet Sci 2020;7:370.
    doi: 10.3389/fvets.2020.00370pmc: PMC7343720pubmed: 32714949google scholar: lookup
  4. Weary DM, Droege P, Braithwaite VA. Behavioral Evidence of Felt Emotions: Approaches, Inferences, and Refinements. Adv Study Behav 2017; 49: 27–48.
    doi: 10.1016/bs.asb.2017.02.002google scholar: lookup
  5. van der Harst JE, Spruijt BM. Tools to measure and improve animal welfare: Reward-related behaviour. Anim Welf 2007; 16(Suppl.): 67–73.
  6. Yeates JW, Main DC. Assessment of positive welfare: a review.. Vet J 2008 Mar;175(3):293-300.
    doi: 10.1016/j.tvjl.2007.05.009pubmed: 17613265google scholar: lookup
  7. Lansade L, Nowak R, Lainé AL, Leterrier C, Bonneau C, Parias C, Bertin A. Facial expression and oxytocin as possible markers of positive emotions in horses.. Sci Rep 2018 Oct 2;8(1):14680.
    doi: 10.1038/s41598-018-32993-zpmc: PMC6168541pubmed: 30279565google scholar: lookup
  8. Laule GE, Bloomsmith MA, Schapiro SJ. The use of positive reinforcement training techniques to enhance the care, management, and welfare of primates in the laboratory.. J Appl Anim Welf Sci 2003;6(3):163-73.
    doi: 10.1207/S15327604JAWS0603_02pubmed: 14612265google scholar: lookup
  9. Lambeth SP, Hau J, Perlman JE, Martino M, Schapiro SJ. Positive reinforcement training affects hematologic and serum chemistry values in captive chimpanzees (Pan troglodytes).. Am J Primatol 2006 Mar;68(3):245-56.
    doi: 10.1002/ajp.20148pubmed: 16477594google scholar: lookup
  10. Hendriksen P, Elmgreen K, Ladewig J. Trailer-loading of horses: Is there a difference between positive and negative reinforcement concerning effectiveness and stress-related signs?. J Vet Behav 2011; 6(5): 261–266.
    doi: 10.1016/j.jveb.2011.02.007google scholar: lookup
  11. Freymond SB, Briefer EF, Zollinger A, Gindrat-von Allmen Y, Wyss C, Bachmann I. Behaviour of horses in a judgment bias test associated with positive or negative reinforcement. Appl Anim Behav Sci 2014; 158: 34–45.
    doi: 10.1016/j.applanim.2014.06.006google scholar: lookup
  12. Dalla Costa E, Minero M, Lebelt D, Stucke D, Canali E, Leach MC. Development of the Horse Grimace Scale (HGS) as a pain assessment tool in horses undergoing routine castration.. PLoS One 2014;9(3):e92281.
    doi: 10.1371/journal.pone.0092281pmc: PMC3960217pubmed: 24647606google scholar: lookup
  13. Wathan J, Burrows AM, Waller BM, McComb K. EquiFACS: The Equine Facial Action Coding System.. PLoS One 2015;10(8):e0131738.
    doi: 10.1371/journal.pone.0131738pmc: PMC4526551pubmed: 26244573google scholar: lookup
  14. Trindade PHE, Hartmann E, Keeling LJ, Andersen PH, Ferraz GC, Paranhos da Costa MJR. Effect of work on body language of ranch horses in Brazil.. PLoS One 2020;15(1):e0228130.
    doi: 10.1371/journal.pone.0228130pmc: PMC6986720pubmed: 31990951google scholar: lookup
  15. Lundblad J, Rashid M, Rhodin M, Haubro Andersen P. Effect of transportation and social isolation on facial expressions of healthy horses.. PLoS One 2021;16(6):e0241532.
    doi: 10.1371/journal.pone.0241532pmc: PMC8177539pubmed: 34086704google scholar: lookup
  16. Young T, Creighton E, Smith T, Hosie C. A novel scale of behavioural indicators of stress for use with domestic horses. Appl Anim Behav Sci 2012; 140(1–2): 33–43.
    doi: 10.1016/j.applanim.2012.05.008google scholar: lookup
  17. Hallgren KA. Computing Inter-Rater Reliability for Observational Data: An Overview and Tutorial.. Tutor Quant Methods Psychol 2012;8(1):23-34.
    doi: 10.20982/tqmp.08.1.p023pmc: PMC3402032pubmed: 22833776google scholar: lookup
  18. Wickham H, Averick M, Bryan J, Chang W, McGowan LD, François R. Welcome to the tidyverse. J Open Source Softw 2019; 4: 1686.
    doi: 10.21105/joss.01686google scholar: lookup
  19. Bates D, Mächler M, Bolker B, Walker S. Fitting linear mixed-effects models using lme4. J Stat Softw 2015; 67.
    doi: 10.18637/jss.v067.i01google scholar: lookup
  20. Peters SM, Bleijenberg EH, van Dierendonck MC, van der Harst JE, Spruijt BM. Characterization of anticipatory behaviour in domesticated horses (Equus caballus). Appl Anim Behav Sci 2012; 138(1–2): 60–69.
    doi: 10.1016/j.applanim.2012.01.018google scholar: lookup
  21. Mal ME, McCall CA, Newland C, Cummins KA. Evaluation of a one-trial learning apparatus to test learning ability in weanling horses. Appl Anim Behav Sci 1993; 35(4): 305–311.
  22. Christensen JW, Rundgren M, Olsson K. Training methods for horses: habituation to a frightening stimulus.. Equine Vet J 2006 Sep;38(5):439-43.
    doi: 10.2746/042516406778400574pubmed: 16986605google scholar: lookup
  23. Hall C, Goodwin D, Heleski C, Randle H, Waran N. Is there evidence of learned helplessness in horses?. J Appl Anim Welf Sci 2008;11(3):249-66.
    doi: 10.1080/10888700802101130pubmed: 18569222google scholar: lookup
  24. Fureix C, Hausberger M, Seneque E, Morisset S, Baylac M, Cornette R, Biquand V, Deleporte P. Geometric morphometrics as a tool for improving the comparative study of behavioural postures.. Naturwissenschaften 2011 Jul;98(7):583-92.
    doi: 10.1007/s00114-011-0803-2pubmed: 21573691google scholar: lookup
  25. Smiet E, Van Dierendonck MC, Sleutjens J, Menheere PP, van Breda E, de Boer D, Back W, Wijnberg ID, van der Kolk JH. Effect of different head and neck positions on behaviour, heart rate variability and cortisol levels in lunged Royal Dutch Sport horses.. Vet J 2014 Oct;202(1):26-32.
    doi: 10.1016/j.tvjl.2014.07.005pubmed: 25127376google scholar: lookup
  26. Hall C, Randle H, Pearson G, Preshaw L, Waran N. Assessing equine emotional state. Appl Anim Behav Sci 2018; 205: 183–193.
    doi: 10.1016/j.applanim.2018.03.006google scholar: lookup
  27. Stratton R, Cogger N, Beausoleil N, Waran N, Stafford K, Steward M. Indicators of good welfare in horses: Final report. MPI Technical Paper, (2014/44). Ministry for Primary Industries, New Zealand Government, 52 p.; 2014.
  28. Reefmann N, Kaszàs FB, Wechsler B, Gygax L. Ear and tail postures as indicators of emotional valence in sheep. Appl Anim Behav Sci 2009; 118(3–4): 199–207.
    doi: 10.1016/j.applanim.2009.02.013google scholar: lookup
  29. Sankey C, Richard-Yris MA, Henry S, Fureix C, Nassur F, Hausberger M. Reinforcement as a mediator of the perception of humans by horses (Equus caballus).. Anim Cogn 2010 Sep;13(5):753-64.
    doi: 10.1007/s10071-010-0326-9pubmed: 20490592google scholar: lookup
  30. Dyson S, Berger J, Ellis AD, Mullard J. Development of an ethogram for a pain scoring system in ridden horses and its application to determine the presence of musculoskeletal pain. J Vet Behav 2018; 23: 47–57.
    doi: 10.1016/J.JVEB.2017.10.008google scholar: lookup
  31. Wathan J, McComb K. The eyes and ears are visual indicators of attention in domestic horses.. Curr Biol 2014 Aug 4;24(15):R677-9.
    doi: 10.1016/j.cub.2014.06.023pmc: PMC4123162pubmed: 25093554google scholar: lookup
  32. Roberts K, Hemmings AJ, Moore-Colyer M, Parker MO, McBride SD. Neural modulators of temperament: A multivariate approach to personality trait identification in the horse.. Physiol Behav 2016 Dec 1;167:125-131.
    doi: 10.1016/j.physbeh.2016.08.029pubmed: 27597134google scholar: lookup
  33. Merkies K, Ready C, Farkas L, Hodder A. Eye Blink Rates and Eyelid Twitches as a Non-Invasive Measure of Stress in the Domestic Horse.. Animals (Basel) 2019 Aug 15;9(8).
    doi: 10.3390/ani9080562pmc: PMC6721043pubmed: 31443315google scholar: lookup
  34. De Boyer Des Roches A, Richard-Yris MA, Henry S, Ezzaouïa M, Hausberger M. Laterality and emotions: visual laterality in the domestic horse (Equus caballus) differs with objects' emotional value.. Physiol Behav 2008 Jun 9;94(3):487-90.
    doi: 10.1016/j.physbeh.2008.03.002pubmed: 18455205google scholar: lookup
  35. Leliveld LMC, Langbein J, Puppe B. The emergence of emotional lateralization: Evidence in non-human vertebrates and implications for farm animals. Appl Anim Behav Sci 2013; 145: 1–14.
    doi: 10.1016/J.APPLANIM.2013.02.002google scholar: lookup
  36. Hockenhull J, Creighton E. Training horses: Positive reinforcement, positive punishment, and ridden behavior problems. J Vet Behav 2013; 8(4): 245–252.
    doi: 10.1016/j.jveb.2012.06.002google scholar: lookup

Citations

This article has been cited 4 times.
  1. Jardat P, Yamamoto S, Ringhofer M, Tanguy-Guillo N, Parias C, Reigner F, Calandreau L, Lansade L. Emotional contagion of fear and joy from humans to horses using a combination of facial and vocal cues. Sci Rep 2025 May 21;15(1):17689.
    doi: 10.1038/s41598-025-98794-3pubmed: 40399542google scholar: lookup
  2. da Fé VCS, Dos Santos VMO, de Lima ACB, Hernandes MSP, Caldara FR, Gomes MNB. Auditory enrichment on facial and physiological responses of Pantaneiro geldings and mares under short-term stress. PLoS One 2025;20(5):e0323649.
    doi: 10.1371/journal.pone.0323649pubmed: 40392914google scholar: lookup
  3. Phelipon R, Bertrand L, Jardat P, Reigner F, Lewis K, Micheletta J, Lansade L. Characterisation of facial expressions and behaviours of horses in response to positive and negative emotional anticipation using network analysis. PLoS One 2025;20(5):e0319315.
    doi: 10.1371/journal.pone.0319315pubmed: 40367029google scholar: lookup
  4. Phelipon R, Lansade L, Razzaq M. Using deep learning models to decode emotional states in horses. Sci Rep 2025 Apr 23;15(1):13154.
    doi: 10.1038/s41598-025-95853-7pubmed: 40269006google scholar: lookup
Subscribe to our newsletter
Join 99,357 horse owners like you who receive our email updates on horse health and nutrition.