Essential oils have been used for millennium. From mummifying royals in ancient Egypt, to being sold as alternative medication for inflammation and migraines.
Their actual function has been at the centre of interminable debate, between personal anecdotes and the medicine community questioning their credibility, it seems everyone has an opinion on them.
But now a team of researchers at the University of Queensland are investigating if the natural products might increase production for Australia's poultry protein industry.
The team are investigating if popular native Australian essential oils - including tea tree oil and eucalyptus - to see if they better equip chicken embryos and hatchlings to fight disease at their most vulnerable moments in life.
Professor Eugeni Roura from UQ's Queensland Alliance for Agriculture and Food Innovation said the study is examining if essential oils' pathogen-fighting properties transfer into the egg.
"We're determining if important essential oil compounds transfer through to the egg, and if they do, are they providing any significant benefit for the embryos' health and robustness," Professor Roura said.
"The most critical period in a broiler chick's life is the first hours after hatching.
"This is when the young bird is more susceptible to environmental pathogens, yet its defences and its natural gut microflora are not well established."
The Australian native essential oils being trialled in the study are tea tree oil, lemon myrtle, nerolina, niaouli, lemon myrtle, anise myrtle, eucalyptus and Tasmanian native pepper.
Research team leader Dr Marta Navarro highlighted that native oils have reported strong antioxidant or disease-fighting attributes.
"This study is aiming to develop a nutritional program to minimise disease in chicks to enhance productivity and sustainability," she said.
She said essential oils could affect how bacteria communicated and spread, inhibiting the formation of bacterial biofilms as an example.
"This may open new possibilities to target non-desirable populations of bacteria in the chick's gut while it is still in the egg," Dr Navarro said.
"Also, the oils can stimulate appetite and digestion to promote strong and vigorous early growth and development."
In a 'chicken or the egg' scenario, another strategy being tested involves injecting essential oils and nutrients into fertile eggs using in-ovo injection technology.
The researchers are measuring multiple parameters and indicators of gut health during trials including microbiome composition, growth, overall embryo development, and the stage of development following fertilisation.
"Once hatched, we're measuring the chick's growth and performance during the first 10-15 days of its life," Dr Navarro said.
"At the end of the project, we'll perform a trial with all the knowledge acquired during the project in commercial conditions."
Meat quality is not part of the scope of the project.
