Essential oils to minimise disease in broiler chicks

Popular native Australian essential oils including lemon myrtle oil and eucalyptus are being studied to determine if they better equip chicken embryos and hatchlings to fight disease. Photo: University of Queensland

Researchers in Australia are investigating the benefits of native essential oils, including lemon myrtle oil and eucalyptus oil, for animal welfare, productivity and sustainability in the Australian chicken meat industry.

“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,” says Professor Eugeni Roura at the University of Queensland’s Queensland Alliance for Agriculture and Food Innovation. He noted that essential oils, which have pathogen-fighting, antimicrobial properties, were being introduced into the diet of breeder chickens to help support a robust microflora in the gut.

In the first few hours after hatching, a broiler chick is more susceptible to environmental pathogens, but its defences and its natural gut microflora are not yet well established, says Roura.

Antioxidant, disease-fighting attributes

The research team is trialling Australian native essential oils including tea tree oil, lemon myrtle, nerolina, niaouli, anise myrtle, eucalyptus, and Tasmanian native pepper, which, according to one of the project leaders, Dr Marta Navarro, have reported strong antioxidant or disease-fighting attributes.

“This study is aiming to develop a nutritional programme to minimise disease in chicks to enhance productivity and sustainability,” she said, adding that essential oils could affect how bacteria communicated and spread, inhibiting the formation of bacterial biofilms, for 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,” Navarro said.

Superbug infections in poultry under the microscope
Researchers report promising results in the fight against superbug infections on poultry farms, which could have wider implication for human health. Find out more…

Early growth and development

According to Navarro, 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, the team will measure the chick’s growth and performance during the first 10-15 days of its life.