Variations of equine urinary volatile compounds during the oestrous cycle.
Abstract: Equine urine was analysed by capillary gas chromatography. The volatile profiles from oestrous and dioestrous samples were compared to establish any qualitative or quantitative difference that may have potential value in olfactory communication. Forty-five different volatile compounds were detected. Of these, 17 major compounds were common to all chromatograms. The chemical profile of oestrous urine was distinguished by the presence of a unique peak that was not present in dioestrous samples. Numerous constituents exhibited endocrine dependence: while the concentrations of seix peaks increased at oestrus, the concentrations of another five peaks decreased at the same time. Since oestrous urine, but not dioestrous urine, has been shown to elicit sexual behaviour in the stallion, the unique peak, together with the peaks that were present in increased concentration at oestrus, may represent important chemical signals that stallions use to detect urinary 'oestrous odours'. Statistical analyses also indicated that the relative ratios (normalized peak areas) of many peaks changed significantly across the oestrous cycle: the rations increased in nine peaks, decreased in six peaks, and remained constant in two peaks at oestrus.
Publication Date: 1997-08-01 PubMed ID: 9266663DOI: 10.1023/a:1005859419574Google Scholar: Lookup
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- Journal Article
Summary
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This research examines the changes in the chemical makeup of horse urine during the oestrous cycle, finding distinct volatile compound profiles that suggest a potential role in olfactory communication for mating purposes.
Objective of the Study
The primary purpose of the study was to analyze variations in the chemical composition of horse urine throughout the oestrous cycle. The researchers aimed to identify any qualitative or quantitative differences in volatile compounds that could have a role in facilitating olfactory communication, particularly as it relates to sexual behaviour and reproductive cycles in horses.
Research Methodology
- Equine urine samples were examined using capillary gas chromatography, a technique potent in separating and identifying various compound mixtures.
- The volatile profiles of oestrous (the period when the female horse, or mare, is in heat and can mate) and dioestrous (resting period in the reproductive cycle when the mare cannot mate) samples were compared.
Findings of the Study
- The study identified 45 different volatile compounds in the urine samples. Out of these, 17 were major compounds detected in all samples.
- The chemical profile of oestrous urine showcased unique peaks not present in the dioestrous urine samples. This difference could be an indicator of chemical communication signaling to male horses s(exually available mares).
- The study also found endocrine-dependent changes. Certain constituent chemicals of the urine experienced fluctuation, with the concentration of six peaks increasing during oestrus and five others decreasing simultaneously.
- Statistical analyses further showed that the relative ratios of many peaks (normalized peak areas) experienced significant changes throughout the oestrous cycle. The ratios increased in nine peaks, decreased in six peaks, and remained constant in two peaks during oestrus.
Implications of the Study
- The findings collectively suggest a potential chemical signaling system present in horse urine.
- The unique peak in oestrous urine and others that increased in concentration during the same phase could act as the chemical signals that male horses detect to identify urinary ‘oestrous odours’.
- This study provides a better understanding of equine reproductive behaviour and could assist vets and breeders in developing improved mare management methods.
Cite This Article
APA
Ma W, Klemm WR.
(1997).
Variations of equine urinary volatile compounds during the oestrous cycle.
Vet Res Commun, 21(6), 437-446.
https://doi.org/10.1023/a:1005859419574 Publication
Researcher Affiliations
- Department of Veterinary Anatomy and Public Health, Texas A & M University, College Station 77843-4458, USA.
MeSH Terms
- Analysis of Variance
- Animals
- Chromatography, Gas
- Diestrus / urine
- Estrus / urine
- Female
- Horses / physiology
- Male
- Odorants
- Sexual Behavior, Animal
References
This article includes 14 references
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Citations
This article has been cited 2 times.- Kannan S, Archunan G. Chemistry of clitoral gland secretions of the laboratory rat: assessment of behavioural response to identified compounds. J Biosci 2001 Jun;26(2):247-52.
- Kumar KR, Archunan G, Jeyaraman R, Narasimhan S. Chemical characterization of bovine urine with special reference to oestrus. Vet Res Commun 2000 Nov;24(7):445-54.
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