FREE SHIPPING over $40
OVER 9000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Home / Equine Research Bank / Animals (Basel) / The Effect of Ambient Temperature, Relative Humidity, and Te...
Animals : an open access journal from MDPI2025; 15(10); 1436; doi: 10.3390/ani15101436

The Effect of Ambient Temperature, Relative Humidity, and Temperature-Humidity Index on Stress Hormone and Inflammatory Response in Exercising Adult Standardbred Horses.

Abstract: In the present study, the changes in the markers of stress and inflammatory responses of 12 Standardbred horses were investigated before and after exercise during late spring and summer. The environmental temperature, relative humidity, and temperature-humidity index (THI) were assessed during this study. From horses, blood sampling, measurement of heart and respiratory rate (HR and RR), and measurement of rectal temperature (RT) were performed before exercise (Pre) and within 5 min following the end of the exercise (Post). THI values showed mild stress in June and high stress in July. Direct erythrocyte indices statistically increased after exercise compared to the rest condition ( < 0.05). Higher serum cortisol, α1-, α2-, and β-globulin values were found at Post than at Pre ( < 0.05), whereas lower serum albumin and A/G ratio values were found at Post than at Pre. The HR, RR, and RT statistically increased at Post than at Pre ( < 0.05). The month influenced the values of RR, platelets, cortisol, albumin, α1-, α2-, and β-globulins ( < 0.05). Overall, the results of this study confirmed the well-recognized physiological response of athletic horses to re-establish homeostasis following exercise.
Get Full Text
Publication Date: 2025-05-15 PubMed ID: 40427313PubMed Central: PMC12108177DOI: 10.3390/ani15101436Google 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.

The research article investigated the correlation between environmental conditions and stress and inflammation levels seen in exercise-performing Standardbred horses. Multiple parameters, like temperature, humidity, temperature-humidity index (THI), and blood, heart, and respiration data were considered, and the results confirmed that exercise impacts the physiological response of horses in an attempt to reestablish stability.

Study Overview

  • The study was conducted on 12 Standardbred horses. These horses were put through exercise routines during late spring and summer.
  • During these exercise sessions, the environmental temperature, humidity and temperature-humidity index (THI) were carefully monitored alongside several health parameters of the horses.
  • Physiological factors such as the horses’ heart and respiratory rates (HR and RR), and their rectal temperature (RT) were measured both before and after each exercise session.
  • THI values from June pointed towards mild stress in horses while those from July suggested high stress.

Bloodwork Findings

  • Bloodwork indicated an increase in direct erythrocyte indices post-exercise compared to pre-exercise levels.
  • Other significant changes in post-exercise bloodwork were higher serum cortisol, α1-, α2-, and β-globulins levels.
  • Conversely, serum albumin and a low albumin-to-globulin ratio (A/G ratio) were observed in the post-exercise measurements.

Physiological Changes

  • Other physiological changes seen after exercise included statistically higher values of HR, RR, and RT.
  • The month or season also had an influencial role on diverse parameters. Variations due to seasonal changes were seen in RR, platelets quantity, cortisol, albumin, α1-, α2-, and β-globulins levels.

Concluding Remarks

  • The conclusion was that exercise does impact the physiological response of horses, an effect that seemed correlated with the attempt of these equines to reestablish their body’s homeostasis after exercise.
  • Combined, the data suggest that varying environmental conditions do impact the stress and inflammatory response in horses in a quantifiable way.

Cite This Article

APA
(2025). The Effect of Ambient Temperature, Relative Humidity, and Temperature-Humidity Index on Stress Hormone and Inflammatory Response in Exercising Adult Standardbred Horses. Animals (Basel), 15(10), 1436. https://doi.org/10.3390/ani15101436

Publication

Animals : an open access journal from MDPI
ISSN: 2076-2615
NlmUniqueID: 101635614
Country: Switzerland
Language: English
Volume: 15
Issue: 10
PII: 1436

Researcher Affiliations

Conflict of Interest Statement

The authors declare no competing interests. None of the authors has any financial or personal relationships that could inappropriately influence or bias the content of the paper.

References

This article includes 26 references
  1. Pérez R, Recabarren S, Valdés P, Hetz E. Biochemical and physiological parameters and estimated work output in draught horses pulling loads for long periods.. Vet. Res. Commun. 1992;16:231–246.
    doi: 10.1007/BF01839160pubmed: 1413484google scholar: lookup
  2. Merino V, Valenzuela S, Cabezas I, García M, Ávila C, Pérez R. Respuesta fisiológica y bioquímica del caballo de tiro a faena de aradura en suelos arroceros.. Arch. Med. Vet. 1997;29:235–241.
    doi: 10.4067/S0301-732X1997000200008google scholar: lookup
  3. Martínez R, Cittar J, Mattioli G, Caviglia J, Giuliodori M, Desmarás E. Fisiología del ejercicio equino. Análisis de una experiencia sobre treadmill de alta velocidad.. Av. Cs. Vet. 2001;16:15–20.
    doi: 10.5354/0716-260X.2001.9212google scholar: lookup
  4. Bobobee E, Gebresenbet G. Effect of cutting edge thickness and state of wear of ploughshare on draught force and heart rates of Sanga oxen in Ghana.. Soil Tillage Res. 2007;95:298–307.
    doi: 10.1016/j.still.2007.01.006google scholar: lookup
  5. Vergara F, Tadich T.A. Effect of the work performed by tourism carriage horses on physiological and blood parameters.. J. Equine Vet. Sci. 2015;35:213–218.
    doi: 10.1016/j.jevs.2014.12.018google scholar: lookup
  6. Kang H, Zsoldos R.R, Sole-Guitart A, Narayan E, Cawdell-Smith A.J, Gaughan J.B. Heat stress in horses: A literature review.. Int. J. Biometeorol. 2023;67:957–973.
    doi: 10.1007/s00484-023-02467-7pmc: PMC10267279pubmed: 37060454google scholar: lookup
  7. Arfuso F, Rizzo M, Arrigo F, Francaviglia F, Perillo L, Schembri P, Zumbo L.E.M, Disclafani R, Piccione G, Monteverde V. Welfare and stress assessment of tourism carriage horses under real working conditions in Sicily.. J. Equine Vet. Sci. 2024;139:105136.
    doi: 10.1016/j.jevs.2024.105136pubmed: 38909767google scholar: lookup
  8. Brownlow M.A, Dart A.J, Jeffcott L.B. Exertional heat illness: A review of the syndrome affecting racing Thoroughbreds in hot and humid climates.. Aust. Vet. J. 2016;94:240–247.
    doi: 10.1111/avj.12454pubmed: 27349884google scholar: lookup
  9. Padalino B, Raidal S.L, Hall E, Knight P, Celi P, Jeffcott L, Muscatello G, Hills R.K. A survey on transport management practices associated with injuries and health problems in horses.. PLoS ONE 2016;11:e0162371.
    doi: 10.1371/journal.pone.0162371pmc: PMC5010189pubmed: 27588689google scholar: lookup
  10. Marco-Ramell A, de Almeida A.M, Cristobal S, Rodrigues P, Roncada P, Bassols A. Proteomics and the search for welfare and stress biomarkers in animal production in the one-health context.. Mol. Biosyst. 2016;12:2024–2035.
    doi: 10.1039/C5MB00788Gpubmed: 26931796google scholar: lookup
  11. Rollin B. Equine welfare and ethics.. .
  12. Aragona F, Arfuso F, Fazio F, De Caro S, Giudice E, Monteverde V, Piccione G, Giannetto C. Circadian variation of peripheral blood cells in horses maintained in different environmental and management conditions.. Animals 2023;13:1865.
    doi: 10.3390/ani13111865pmc: PMC10251899pubmed: 37889772google scholar: lookup
  13. Elenkov I.J, Chrousos G.P. Stress hormones, proinflammatory and antiinflammatory cytokines, and autoimmunity.. Ann. N. Y. Acad. Sci. 2002;966:290–303.
    doi: 10.1111/j.1749-6632.2002.tb04229.xpubmed: 12114286google scholar: lookup
  14. Aleri J.W, Hine B.C, Pyman M.F, Mansell P, Wales W.J, Mallard B, Fisher A.D. Periparturient immunosuppression and strategies to improve dairy cow health during the periparturient period.. Res. Vet. Sci. 2016;108:8–17.
    doi: 10.1016/j.rvsc.2016.07.007pubmed: 27663364google scholar: lookup
  15. Persson S.G.B, Lydin G. Circulatory effects of splenectomy in the horse: III. Effect on pulse-work relationship.. Zentralbl. Veterinarmed. A. 1973;20:521.
    doi: 10.1111/j.1439-0442.1973.tb01066.xpubmed: 4203623google scholar: lookup
  16. Rose R.J, Allen J.R. Hematologic responses to exercise and training.. J. N. Am. Equine Pract. 1985;1:461.
    doi: 10.1016/S0749-0739(17)30745-9pubmed: 3877551google scholar: lookup
  17. Grzędzicka J, Dąbrowska I, Malin K, Witkowska-Piłaszewicz O. Exercise-related changes in the anabolic index (testosterone to cortisol ratio) and serum amyloid A concentration in endurance and racehorses at different fitness levels.. Front. Vet. Sci. 2023;10:1148990.
    doi: 10.3389/fvets.2023.1148990pmc: PMC10150884pubmed: 37138908google scholar: lookup
  18. De Luccia T.P.B. Use of the Testosterone/Cortisol Ratio Variable in Sports.. Open Sports Sci. J. 2016;9:104–113.
    doi: 10.2174/1875399X01609010104google scholar: lookup
  19. Rammerstorfer C, Potter G.D, Brumbaugh G.W, Gibbs P.G, Varner D.D, Rammerstorfer E.H. Physiologic responses of acclimatized or non-acclimatized mature reining horses to heat stress: I. heart rate, respiration rate, lactate, rectal temperature, cortisol and packed cell volume.. J. Equine Vet. Sci. 2001;21:431–438.
    doi: 10.1016/S0737-0806(01)70017-2google scholar: lookup
  20. Persson S.G.B. Heart rate and blood lactate responses to submaximal treadmill exercise in the normally performing standardbred trotter. Age and sex variations and predictability from total red blood cell volume.. Zentralbl. Veterinarmed. A. 1997;44:125–132.
    doi: 10.1111/j.1439-0442.1997.tb01094.xpubmed: 9197201google scholar: lookup
  21. Pérez R, Iglesias V, Cabezas I, García M, Ibañez M. Relación entre el trabajo realizado y la respuesta cardio-respiratoria al ejercicio en dos grupos de caballos de tiro.. Arch. Med. Vet. 1994;26:15–28.
  22. Franklin S.H, Van Erck-Westergren E, Bayli W.M. Respiratory responses to exercise in the horse.. Equine Vet. J. 2012;44:726–732.
    doi: 10.1111/j.2042-3306.2012.00666.xpubmed: 23106622google scholar: lookup
  23. de Mira M.C, Lamy E, Santos R, Williams J, Pinto M.V, Martins P.S, Rodrigues P, Marlin D. Salivary cortisol and eye temperature changes during endurance competitions.. BMC Vet. Res. 2021;17:329.
    doi: 10.1186/s12917-021-02985-9pmc: PMC8515720pubmed: 34649565google scholar: lookup
  24. Wallsten H, Olsson K, Dahlborn K. Temperature regulation in horses during exercise and recovery in a cool environment.. Acta Vet. Scand. 2012;54:42.
    doi: 10.1186/1751-0147-54-42pmc: PMC3427134pubmed: 22805591google scholar: lookup
  25. Morgan K. Thermoneutral zone and critical temperatures of horses.. J. Therm. Biol. 1998;23:59–61.
    doi: 10.1016/S0306-4565(97)00047-8google scholar: lookup
  26. Ott E.A. Influence of temperature stress on the energy and protein metabolism and requirements of the working horse.. Livest. Prod. Sci. 2005;92:123–130.
    doi: 10.1016/j.livprodsci.2004.11.015google scholar: lookup

Citations

This article has been cited 0 times.
Subscribe to our newsletter
Join 99,357 horse owners like you who receive our email updates on horse health and nutrition.