Location: Livestock Nutrient Management ResearchTitle: Chemical characterization of the marking fluid of breeding and non-breeding male cheetahs
|TOMMASI, ALEXIA - STELLENBOSCH UNIVERSITY|
|TREDOUX, ANDREAS - STELLENBOSCH UNIVERSITY|
|ESPOSITO, GIULIA - UNIVERSITY OF PARMA|
Submitted to: Animals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/28/2022
Publication Date: 9/3/2022
Citation: Tommasi, A., Tredoux, A.G., Koziel, J.A., Esposito, G. 2022. Chemical characterization of the marking fluid of breeding and non-breeding male cheetahs. Animals. 12(17). Article 2284. https://doi.org/10.3390/ani12172284.
Interpretive Summary: Typically when agricultural engineers are working on odors they are striving to reduce scents and odors that are offensive to people. However, among mammals, scent and odors are routinely used to fulfil critical functions like eating, reproduction, etc. In fact, marking fluids that animals spray on objects are used to transmit certain messages that are detectable to other animals. The purpose of scent marks is to mark territory, identify neighbors, detect bigger predators and nearby food/prey, signal alarms and attract members of the opposite sex. This study aimed at chemically characterizing the marking fluid of both breeding and non-breeding male cheetahs (Acinonyx jubatus). Specifically, it focused on identifying potential differences in semiochemicals (pheromones) related to sexual behavior/attraction in this species. Furthermore, it aimed at providing more information as a basis for future studies, such as the investigation of specific semiochemicals in the reproductive behaviour of cheetahs. The results of this study support the hypothesis of differences in the relative concentration of volatile organic compounds emitted from marking fluids between male cheetahs. They highlight the importance of diet and age on the presence of these compounds in the marking fluid. This, in turn, would aid in improving captive breeding, the prevention of asymmetric reproductive aging, and wildlife conservation efforts.
Technical Abstract: Scent is known to play an important role in reproduction of cheetahs and other felids. In fact, the presence/odour of a male cheetah has been noted to trigger the oestrous cycle in the females. The objective of this study was to analyse the marking fluid (MF) of male cheetahs from different breeding groups to determine the composition of volatile organic compounds (VOCs) present, with the aim of identifying potential pheromones relating to sexual behaviour/attraction in this species. Four breeding (B; age: 8.9±1.3 years old) and 4 non-breeding (NB; age: 5.5±0.8 years old) males were selected for this study. Samples were collected into a glass beaker, transferred immediately into a 20 mL glass screw-cap vial with a polytetrafluoroethylene (PTFE) coated silicone septum, and stored until analysed by headspace solid-phase microextraction (HS-SPME) using gas-chromatography mass-spectrometry. A contingency test with Fisher’s exact test, using the frequency (FREQ) procedure of SAS 9.4, was conducted to determine the difference between the number of VOCs identified per breeding group; furthermore, differences in relative concentration (RC) of the identified VOCs between breeding groups were analysed using ANOVA for repeated measures with the GLIMMIX procedure. From the 13 MF samples analysed, 53 VOCs were identified and 12 were identified in all the samples. Five of these (dimethyl disulfide, benzaldehyde, acetophenone, phenol and indole) are known to be involved in attraction/sexual behaviour in mammals. Between the two groups, the RC of indole was significantly higher in the NB group, whereas the RC of dodecanoic acid was significantly higher in the B group. Although not significant, benzaldehyde was numerically higher in the B versus the NB group. The results of this study do support the hypothesis of differences in VOCs’ between B and NB male cheetahs. However, the overlapping of age and breeding status, and the diet differences could not be controlled. Still, the evidence of changes in MF composition in male cheetahs necessitates further studies towards possible strategies to improve reproduction in captivity.