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Animals : an open access journal from MDPI2023; 13(20); 3180; doi: 10.3390/ani13203180

Olfactory Stimulation as Environmental Enrichment for Domestic Horses-A Review.

Abstract: Horses constantly face several challenges inherent to the domestic environment, and it is common for the expression of their natural behavior to be drastically limited. Environmental enrichment has been suggested as an alternative to improve the captive situation of domestic horses. Among the recently proposed enrichment strategies, olfactory stimulation has emerged as a method for improving several aspects related to animal behavior. Olfaction is a sensory modality that plays a significant role in the expression of equine behavior, and in recent years, studies have shown that olfactory stimulation can influence the physiological and behavioral parameters of horses. This review provides current information on the anatomical particularities of the equine olfactory system, presents the physiological mechanisms involved in the odor detection process, and demonstrates how stress can interfere with this process. Finally, the use of olfactory stimulation as an environmental enrichment for domestic horses () is explored. The need for new studies that answer pertinent questions related to this topic is discussed throughout the manuscript.
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Publication Date: 2023-10-12 PubMed ID: 37893904PubMed Central: PMC10603683DOI: 10.3390/ani13203180Google 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.

The research article studies the potential benefits of using olfactory stimulation as a way to enhance the living conditions for domestic horses. The method is discussed in light of its effects on horse behavior and the impacts of stress on these animals.

Anatomical and Physiological Particularities of the Equine Olfactory System

  • The research provides a detailed analysis of the olfactory system of horses. It was noted that this system plays a critical aspect of a horse’s behavior, hence the authors lay emphasis on understanding its structure and functionalities.
  • While describing the anatomical details of a horse’s sensory system, the processes involved in odor detection are also introduced. The authors explain that these mechanisms are indispensable for understanding how olfactory stimulation can improve a domestic horse’s physiological and behavioral traits.

Effect of Stress on Equine Olfaction

  • The topic of stress on equines and its interference with their ability to recognize smells is addressed in the research. Stress, which can be induced by the conditions the domestic horse lives in, may hinder the functioning of its olfactory system.
  • By highlighting this relationship, it is inferred that an enriched environment that could reduce stress levels would also improve the functioning of the olfactory system, adding another layer to why olfactory stimulation might prove advantageous for horses.

Olfactory Stimulation as Environmental Enrichment

  • The concept of olfactory stimulation is presented as a novel approach to environmental enrichment for domestic horses. By exposing horses to different smells, the authors argue that their captive situation could be drastically improved.
  • Studies which point to the influence of olfactory stimulation on the behavioral and physical parameters of horses are cited, providing evidence for the potential positive outcomes of such an enrichment strategy.

Future Study Recommendations

  • The article ends with a call for further studies on the subject, particular questions and areas of uncertainty are mentioned, indicating the direction future research could take.
  • Such a call emphasizes the novelty of the concept, importance of the subject matter, and the recognition that the full extent of the potential benefits of olfactory stimulation on domestic horses are yet unknown.

Cite This Article

APA
Bini de Lima AC, Sebastião da Fé VC, Palermo Hernandes MS, Oliveira Dos Santos VM. (2023). Olfactory Stimulation as Environmental Enrichment for Domestic Horses-A Review. Animals (Basel), 13(20), 3180. https://doi.org/10.3390/ani13203180

Publication

Animals : an open access journal from MDPI
ISSN: 2076-2615
NlmUniqueID: 101635614
Country: Switzerland
Language: English
Volume: 13
Issue: 20
PII: 3180

Researcher Affiliations

Bini de Lima, Ana Caroline
  • Nucleus of Studies in Ambience, Bioclimatology, Welfare and Ethology, Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, Brazil.
Sebastião da Fé, Vanessa Cristini
  • Nucleus of Studies in Ambience, Bioclimatology, Welfare and Ethology, Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, Brazil.
Palermo Hernandes, Maria Simara
  • Nucleus of Studies in Ambience, Bioclimatology, Welfare and Ethology, Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, Brazil.
Oliveira Dos Santos, Viviane Maria
  • Nucleus of Studies in Ambience, Bioclimatology, Welfare and Ethology, Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, Brazil.

Conflict of Interest Statement

The authors declare no conflict of interest.

References

This article includes 77 references
  1. McGreevy P, Christensen JW, von Borstel UK, McLean A. Equitation Science. 2nd ed. John Wiley & Sons; Hoboken, NJ, USA: 2018.
  2. Budzyńska M. Stress Reactivity and Coping in Horse Adaptation to Environment. J. Equine Vet. Sci. 2014;34:935–941.
    doi: 10.1016/j.jevs.2014.05.010google scholar: lookup
  3. Sarrafchi A, Blokhuis HJ. Equine Stereotypic Behaviors: Causation, Occurrence, and Prevention. J. Vet. Behav. Clin. Appl. Res. 2013;8:386–394.
    doi: 10.1016/j.jveb.2013.04.068google scholar: lookup
  4. Lansade L, Valenchon M, Foury A, Neveux C, Cole SW, Layé S, Cardinaud B, Lévy F, Marie M, Moisan M-P. Behavioral and Transcriptomic Fingerprints of an Enriched Environment in Horses (Equus caballus). PLoS ONE 2014;9:e114384.
    doi: 10.1371/journal.pone.0114384pmc: PMC4262392pubmed: 25494179google scholar: lookup
  5. Nielsen BL, Jezierski T, Bolhuis JE, Amo L, Rosell F, Oostindjer M, Christensen JW, McKeegan D, Wells DL, Hepper P. Olfaction: An Overlooked Sensory Modality in Applied Ethology and Animal Welfare. Front. Vet. Sci. 2015;2:1–3.
    doi: 10.3389/fvets.2015.00069pmc: PMC4672279pubmed: 26664995google scholar: lookup
  6. Rørvang MV, Nielsen BL, McLean AN. Sensory Abilities of Horses and Their Importance for Equitation Science. Front. Vet. Sci. 2020;7:1–17.
    doi: 10.3389/fvets.2020.00633pmc: PMC7509108pubmed: 33033724google scholar: lookup
  7. Guillaume D, Moussu C, de Geoffroy F, Chesneau D, Keller M. Olfactory Stimulation or Inhibition of Sexual Behavior of Stallions in Non-Breeding Season. Physiol. Behav. 2018;186:1–9.
    doi: 10.1016/j.physbeh.2017.12.031pubmed: 29287623google scholar: lookup
  8. Heitman K, Rabquer B, Heitman E, Streu C, Anderson P. The Use of Lavender Aromatherapy to Relieve Stress in Trailered Horses. J. Equine Vet. Sci. 2018;63:8–12.
    doi: 10.1016/j.jevs.2017.12.008google scholar: lookup
  9. Rørvang MV, Nicova K, Yngvesson J. Testing Olfaction in Equids: Age and Gestational Stage Affects Olfactory Interest. Res. Sq. 2021.
    doi: 10.21203/rs.3.rs-957361/v1google scholar: lookup
  10. Ferguson CE, Kleinman HF, Browning J. Effect of Lavender Aromatherapy on Acute-Stressed Horses. J. Equine Vet. Sci. 2013;33:67–69.
    doi: 10.1016/j.jevs.2012.04.014google scholar: lookup
  11. Bombail V. Perception and Emotions: On the Relationships between Stress and Olfaction. Appl. Anim. Behav. Sci. 2019;212:98–108.
    doi: 10.1016/j.applanim.2018.12.013google scholar: lookup
  12. Guffanti P, Pifferi V, Falciola L, Ferrante V. Analyses of Odours from Concentrated Animal Feeding Operations: A Review. Atmos. Environ. 2018;175:100–108.
    doi: 10.1016/j.atmosenv.2017.12.007google scholar: lookup
  13. Leblanc MA. The Mind of the Horse: An Introduction to Equine Cognition. Harvard University Press; Cambridge, MA, USA: 2013.
  14. Farooqui T. Trace Amines and Neurological Disorders. Elsevier Inc.; Amsterdam, The Netherlands: 2016. Trace Amine-Mediated Olfactory Learning and Memory in Mammals and Insects: A Brief Comparative Review; pp. 181–202.
  15. Saslow CA. Understanding the Perceptual World of Horses. Appl. Anim. Behav. Sci. 2002;78:209–224.
    doi: 10.1016/S0168-1591(02)00092-8google scholar: lookup
  16. Mellor DJ, Beausoleil NJ. Equine Welfare during Exercise: An Evaluation of Breathing, Breathlessness and Bridles. Animals 2017;7:41.
    doi: 10.3390/ani7060041pmc: PMC5483604pubmed: 28587125google scholar: lookup
  17. Niimura Y, Matsui A, Touhara K. Erratum: Extreme Expansion of the Olfactory Receptor Gene Repertoire in African Elephants and Evolutionary Dynamics of Orthologous Gene Groups in 13 Placental Mammals. Genome Res. 2014;24:1485–1496.
    doi: 10.1101/gr.169532.113pmc: PMC4158756pubmed: 25053675google scholar: lookup
  18. Fraser AF. The Behaviour and Welfare of the Horse. 2nd ed. CABI Publishing; Wallingford, UK: 2010.
  19. Smith LCR. Surgical Access to the Nasal Cavities in the Horse. Equine Vet. Educ. 2017;29:70–71.
    doi: 10.1111/eve.12611google scholar: lookup
  20. Davies Z. Equine Science. 3rd ed. Wiley-Blackwell; Hoboken, NJ, USA: 2017.
  21. Buzek A, Serwańska-Leja K, Zaworska-Zakrzewska A, Kasprowicz-Potocka M. The Shape of the Nasal Cavity and Adaptations to Sniffing in the Dog (Canis Familiaris) Compared to Other Domesticated Mammals: A Review Article. Animals 2022;12:517.
    doi: 10.3390/ani12040517pmc: PMC8868339pubmed: 35203225google scholar: lookup
  22. Kupke A, Wenisch S, Failing K, Herden C. Intranasal Location and Immunohistochemical Characterization of the Equine Olfactory Epithelium. Front. Neuroanat. 2016;10:1–17.
    doi: 10.3389/fnana.2016.00097pmc: PMC5061740pubmed: 27790096google scholar: lookup
  23. Meunier N, Rampin O. The Nuts and Bolts of Olfaction. In: Nielsen BL, editor. Olfaction in Animal Behaviour and Welfare. CABI Publishing; Wallingford, UK: 2017. pp. 1–15.
  24. Reece WO, Rowe EW. Functional Anatomy and Physiology of Domestic Animals. 5th ed. Wiley-Blackwell; Hoboken, NJ, USA: 2017.
  25. Kurian SM, Naressi RG, Manoel D, Barwich AS, Malnic B, Saraiva LR. Odor Coding in the Mammalian Olfactory Epithelium. Cell Tissue Res. 2021;383:445–456.
    doi: 10.1007/s00441-020-03327-1pmc: PMC7873010pubmed: 33409650google scholar: lookup
  26. Kaupp UB. Olfactory Signalling in Vertebrates and Insects: Differences and Commonalities. Nat. Rev. Neurosci. 2010;11:188–200.
    doi: 10.1038/nrn2789pubmed: 20145624google scholar: lookup
  27. Reece WO, Erickson HH, Goff JP, Uemura EE. Dukes’ Physiology of Domestic Animals. 13th ed. Wiley-Blackwell; Hoboken, NJ, USA: 2015.
  28. Ross JM, Fletcher ML. Aversive Learning-Induced Plasticity throughout the Adult Mammalian Olfactory System: Insights across Development. J. Bioenerg. Biomembr. 2019;51:15–27.
    doi: 10.1007/s10863-018-9770-zpmc: PMC6382525pubmed: 30171506google scholar: lookup
  29. Merkies K, Paraschou G, McGreevy PD. Morphometric Characteristics of the Skull in Horses and Donkeys—A Pilot Study. Animals 2020;10:1002.
    doi: 10.3390/ani10061002pmc: PMC7341236pubmed: 32521777google scholar: lookup
  30. Kokocińska-Kusiak A, Woszczyło M, Mikolaj Z, Maciocha J, Barłowska K. Canine Olfaction: Physiology, Behavior, and Possibilities for Practical Applications. Animals 2021;11:2463.
    doi: 10.3390/ani11082463pmc: PMC8388720pubmed: 34438920google scholar: lookup
  31. Siniscalchi M, Padalino B, Aubé L, Quaranta A. Right-Nostril Use during Sniffing at Arousing Stimuli Produces Higher Cardiac Activity in Jumper Horses. Laterality 2015;20:483–500.
    doi: 10.1080/1357650X.2015.1005629pubmed: 25635853google scholar: lookup
  32. Lee KH, Park C, Kim J, Moon C, Ahn M, Shin T. Histological and Lectin Histochemical Studies of the Vomeronasal Organ of Horses. Tissue Cell. 2016;48:361–369.
    doi: 10.1016/j.tice.2016.05.002pubmed: 27233915google scholar: lookup
  33. Singh B. Dyce, Sack, and Wensing’s Textbook of Veterinary Anatomy. 5th ed. Saunders; Collingwood, ON, Canada: 2018.
  34. Kostov DL, Zagora S. Vomeronasal Organ in Domestic Animals. Bulg. J. Vet. Med. 2007;10:53–57.
  35. Yokosuka M. Histological Properties of the Glomerular Layer in the Mouse Accessory Olfactory Bulb. Exp. Anim. 2012;61:13–24.
    doi: 10.1538/expanim.61.13pubmed: 22293668google scholar: lookup
  36. Young JM, Division BJT. V2R Gene Families Degenerated in Primates, Dog and Cow, but Expanded in Opossum. Trends Genet. 2007;23:212–215.
    doi: 10.1016/j.tig.2007.03.004pubmed: 17382427google scholar: lookup
  37. Mohrhardt J, Nagel M, Fleck D, Ben-Shaul Y, Spehr M. Signal Detection and Coding in the Accessory Olfactory System Abbreviated. Chem. Senses. 2018;43:667–695.
    doi: 10.1093/chemse/bjy061pmc: PMC6211456pubmed: 30256909google scholar: lookup
  38. Beaver BV. Equine Behavioral Medicine. Elseviser; Amsterdam, The Netherlands: 2019.
  39. Spehr M, Spehr J, Ukhanov K, Kelliher KR, Leinders-Zufall T, Zufall F. Parallel Processing of Social Signals by the Mammalian Main and Accessory Olfactory Systems. Cell. Mol. Life Sci. 2006;63:1476–1484.
    doi: 10.1007/s00018-006-6109-4pubmed: 16732428google scholar: lookup
  40. Scalia F, Winans SS. The Differential Projections of the Olfactory Bulb and Accessory Olfactory Bulb in Mammals. J. Comp. Neurol. 1975;161:31–55.
    doi: 10.1002/cne.901610105pubmed: 1133226google scholar: lookup
  41. Martínez-García F, Martínez-Ricós J, Agustín-Pavón C, Martínez-Hernández J, Novejarque A, Lanuza E. Refining the Dual Olfactory Hypothesis: Pheromone Reward and Odour Experience. Behav. Brain Res. 2009;200:277–286.
    doi: 10.1016/j.bbr.2008.10.002pubmed: 18977394google scholar: lookup
  42. Choi Y, Yoon M. The Expression of Androstenone Receptor (OR7D4) in Vomeronasal Organ and Olfactory Epithelium of Horses. Domest. Anim. Endocrinol. 2021;74:106535.
    doi: 10.1016/j.domaniend.2020.106535pubmed: 32896801google scholar: lookup
  43. Bombail V. The Role of Olfaction in Relation to Stress and Fear. In: Lindstrøm Nielsen B, editor. Olfaction in Animal Behaviour and Welfare. CABI Publishing; Wallingford, UK: 2017. pp. 136–150.
  44. Fureix C, Jego P, Henry S, Lansade L, Hausberger M. Towards an Ethological Animal Model of Depression? A Study on Horses. PLoS ONE 2012;7:e39280.
    doi: 10.1371/journal.pone.0039280pmc: PMC3386251pubmed: 22761752google scholar: lookup
  45. Clouard C, Bolhuis JE. Olfactory Behaviour in Farm Animals. In: Nielsen B.L., editor. Olfaction in Animal Behaviour and Welfare. CABI Publishing; Wallingford, UK: 2017. pp. 161–175.
  46. Christensen JW, Rundgren M. Predator Odour per Se Does Not Frighten Domestic Horses. Appl. Anim. Behav. Sci. 2008;112:136–145.
    doi: 10.1016/j.applanim.2007.08.003google scholar: lookup
  47. Špinka M. Social Dimension of Emotions and Its Implication for Animal Welfare. Appl. Anim. Behav. Sci. 2012;138:170–181.
    doi: 10.1016/j.applanim.2012.02.005google scholar: lookup
  48. Moberg GP, Mench JA. The Biology of Animal Stress: Basic Principles and Implications for Animal Welfare. CABI Publishing; Wallingford, UK: 2000.
  49. Sabiniewicz A, Tarnowska K, Świątek R, Sorokowski P, Laska M. Olfactory-Based Interspecific Recognition of Human Emotions: Horses (Equus Ferus Caballus) Can Recognize Fear and Happiness Body Odour from Humans (Homo Sapiens). Appl. Anim. Behav. Sci. 2020;230:105072.
    doi: 10.1016/j.applanim.2020.105072google scholar: lookup
  50. Poutaraud A, Guilloteau L, Gros C, Lobstein A, Meziani S, Steyer D, Moisan MP, Foury A, Lansade L. Lavender Essential Oil Decreases Stress Response of Horses. Environ. Chem. Lett. 2018;16:539–544.
    doi: 10.1007/s10311-017-0681-8google scholar: lookup
  51. Falewee C, Gaultier E, Lafont C, Bougrat L, Pageat P. Effect of a Synthetic Equine Maternal Pheromone during a Controlled Fear-Eliciting Situation. Appl. Anim. Behav. Sci. 2006;101:144–153.
    doi: 10.1016/j.applanim.2006.01.008google scholar: lookup
  52. Newberry RC. Environmental Enrichment: Increasing the Biological Relevance of Captive Environments. Appl. Anim. Behav. Sci. 1995;44:229–243.
    doi: 10.1016/0168-1591(95)00616-Zgoogle scholar: lookup
  53. Young RJ. Environmental Enrichment for Captive Animals. Wiley-Blackwell; Hoboken, NJ, USA: 2003.
  54. Wells DL. Sensory Stimulation as Environmental Enrichment for Captive Animals: A Review. Appl. Anim. Behav. Sci. 2009;118:1–11.
    doi: 10.1016/j.applanim.2009.01.002google scholar: lookup
  55. Murtagh K, Farnworth MJ, Brilot BO. The Scent of Enrichment: Exploring the Effect of Odour and Biological Salience on Behaviour during Enrichment of Kennelled Dogs. Appl. Anim. Behav. Sci. 2020;223:104917.
    doi: 10.1016/j.applanim.2019.104917google scholar: lookup
  56. Ellis SLH, Wells DL. The Influence of Olfactory Stimulation on the Behaviour of Cats Housed in a Rescue Shelter. Appl. Anim. Behav. Sci. 2010;123:56–62.
    doi: 10.1016/j.applanim.2009.12.011google scholar: lookup
  57. Wilson SC, Mitlöhner FM, Morrow-Tesch J, Dailey JW, McGlone JJ. An Assessment of Several Potential Enrichment Devices for Feedlot Cattle. Appl. Anim. Behav. Sci. 2002;76:259–265.
    doi: 10.1016/S0168-1591(02)00019-9google scholar: lookup
  58. Clark F, King AJ. A Critical Review of Zoo-Based Olfactory Enrichment. In: Hurst JL, Beynon RJ, Roberts SC, Wyatt TD, editors. Chemical Signals in Vertebrates 11. Springer; Berlin/Heidelberg, Germany: 2008. pp. 391–398.
  59. Guarneros M, Sánchez-García O, Martínez-Gómez M, Arteaga L. The Underexplored Role of Chemical Communication in the Domestic Horse, Equus Caballus. J. Vet. Behav. 2020;38:89–95.
    doi: 10.1016/j.jveb.2020.05.008google scholar: lookup
  60. Lansade L, Pichard G, Leconte M. Sensory Sensitivities: Components of a Horse’s Temperament Dimension. Appl. Anim. Behav. Sci. 2008;114:534–553.
    doi: 10.1016/j.applanim.2008.02.012google scholar: lookup
  61. Baker B, Taylor S, Montrose VT. The Effects of Olfactory Stimulation on the Behavior of Captive Ring-Tailed Lemurs (Lemur Catta). Zoo Biol. 2018;37:16–22.
    doi: 10.1002/zoo.21392pubmed: 29239483google scholar: lookup
  62. Fendt M, Apfelbach R, Slotnick B. Behavioural Tests of Olfaction. In: Nielsen B.L., editor. Olfaction in Animal Behaviour and Welfare. CABI Publishing; Wallingford, UK: 2017. pp. 39–60.
  63. Hothersall B, Harris P, Sörtoft L, Nicol CJ. Discrimination between Conspecific Odour Samples in the Horse (Equus caballus). Appl. Anim. Behav. Sci. 2010;126:37–44.
    doi: 10.1016/j.applanim.2010.05.002google scholar: lookup
  64. Jezierski T, Jaworski Z, Sobczyńska M, Ensminger J, Górecka-Bruzda A. Do Olfactory Behaviour and Marking Responses of Konik Polski Stallions to Faeces from Conspecifics of Either Sex Differ?. Behav. Processes. 2018;155:38–42.
    doi: 10.1016/j.beproc.2017.09.015pubmed: 28962880google scholar: lookup
  65. Krueger K, Flauger B. Olfactory Recognition of Individual Competitors by Means of Faeces in Horse (Equus caballus). Anim. Cogn. 2011;14:245–257.
    doi: 10.1007/s10071-010-0358-1pubmed: 21132447google scholar: lookup
  66. Kekan PM, Ingole SD, Sirsat SD, Bharucha SV, Kharde SD, Nagvekar AS. The Role of Pheromones in Farm Animals-A Review. Agric. Rev. 2017;38:83–93.
    doi: 10.18805/ag.v38i02.7939google scholar: lookup
  67. Alves de Paula R, Cruz Aleixo AS, Peternelli da Silva L, Grandi MC, Tsunemi MH, Lourenço MLG, Chiacchio SB. A Test of the Effects of the Equine Maternal Pheromone on the Clinical and Ethological Parameters of Equines Undergoing Hoof Trimming. J. Vet. Behav. 2019;31:28–35.
    doi: 10.1016/j.jveb.2019.01.005google scholar: lookup
  68. Berger JM, Spier SJ, Davies R, Gardner IA, Leutenegger CM, Bain M. Behavioral and Physiological Responses of Weaned Foalstreated with Equine Appeasing Pheromone: A Double-Blinded, Placebo-Controlled, Randomized Trial. J. Vet. Behav. Clin. Appl. Res. 2013;8:265–277.
    doi: 10.1016/j.jveb.2012.09.003google scholar: lookup
  69. Graham L, Wells DL, Hepper PG. The Influence of Olfactory Stimulation on the Behaviour of Dogs Housed in a Rescue Shelter. Appl. Anim. Behav. Sci. 2005;91:143–153.
    doi: 10.1016/j.applanim.2004.08.024google scholar: lookup
  70. Won CL, Jeong MS, Chun IL, Hyeong BP, Bum CL. Stimulative and Sedative Effects of Essential Oils upon Inhalation in Mice. Arch. Pharm. Res. 2005;28:770–774.
    doi: 10.1007/BF02977341pubmed: 16114490google scholar: lookup
  71. Hashemi SR, Davoodi H. Herbal Plants and Their Derivatives as Growth and Health Promoters in Animal Nutrition. Vet. Res. Commun. 2011;35:169–180.
    doi: 10.1007/s11259-010-9458-2pubmed: 21213046google scholar: lookup
  72. Bennett RN, Wallsgrove RM. Secondary Metabolites in Plant Defence Mechanisms. New Phytol. 1994;127:617–633.
    doi: 10.1111/j.1469-8137.1994.tb02968.xpubmed: 33874382google scholar: lookup
  73. Krishan G, Narang A. Use of Essential Oils in Poultry Nutrition: A New Approach. J. Adv. Vet. Anim. Res. 2014;1:156–162.
    doi: 10.5455/javar.2014.a36google scholar: lookup
  74. De Sousa DP, De Almeida Soares Hocayen P, Andrade LN, Andreatini R. A Systematic Review of the Anxiolytic-like Effects of Essential Oils in Animal Models. Molecules 2015;20:18620–18660.
    doi: 10.3390/molecules201018620pmc: PMC6332383pubmed: 26473822google scholar: lookup
  75. Baldwin AL, Chea I. Effect of Aromatherapy on Equine Heart Rate Variability. J. Equine Vet. Sci. 2018;68:46–50.
    doi: 10.1016/j.jevs.2018.05.213pubmed: 31256887google scholar: lookup
  76. Kosiara S, Harrison AP. The Effect of Aromatherapy on Equine Facial Expression, Heart Rate, Respiratory Tidal Volume and Spontaneous Muscle Contractures in M. Temporalis and M. Cleidomastoideus. Open J. Vet. Med. 2021;11:87–103.
    doi: 10.4236/ojvm.2021.112005google scholar: lookup
  77. Wells DL, Hepper PG. The Role of Olfaction in Animal Housing and as Enrichment. In: Nielsen B.L., editor. Olfaction in Animal Behaviour and Welfare. CABI Publishing; Wallingford, UK: 2017. pp. 151–160.

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