Popular native Australian essential oils including tea tree oil and eucalyptus are being studied to determine if they better equip chicken embryos and hatchlings to fight disease.

University of Queensland researchers are investigating the benefits of essential oils for animal welfare, productivity and sustainability in the Australian chicken meat industry.

Professor Eugeni Roura from UQ’s Queensland Alliance for Agriculture and Food Innovation said essential oils, which have pathogen-fighting properties, were being introduced into the diet of breeder chickens.

“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 research team, including project leaders Dr Marta Navarro and Dr Shahram Niknafs, is trialling Australian native essential oils including tea tree oil, lemon myrtle, nerolina, niaouli, lemon myrtle, anise myrtle, eucalyptus and Tasmanian native pepper.

“These native oils have reported strong antioxidant or disease-fighting attributes and have been extensively studied here at UQ,” Dr Navarro said.

“This study is aiming to develop a nutritional program to minimise disease in chicks to enhance productivity and sustainability.”

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.”

This project is funded by AgriFutures Chicken Meat Program and supported by the Queensland Department of Agriculture and Fisheries and UQ.

Meat quality is not part of the scope of the project.

Image: – Dr Shahram Niknafs holding a chick