Generations of cooks have known that seasoning chicken with herbs like sage, basil and thyme adds to our eating pleasure.

Now researchers at Scotland’s Rural College have found that feeding herbs to growing chickens can mean a bigger portion on your plate!

A nutrition experiment carried out by researchers from SRUC’s Avian Research Centre in Ayr revealed that a mix of essential oils including lemon, thyme and sage improves the bird’s growth rate, which means more breast meat for consumers.

Unfortunately the essential oils do not affect the flavour of the bird. However, the researchers believe that they increase the amount of digestive enzymes in the chickens’ gut which help them absorb more nutrients and gain weight.

Previous research showed that essential oils can offer a promising alternative to antibiotics due to their antibacterial, antifungal, and antiviral properties, yet there have been fewer studies suggesting they promote growth. However this particular mix of essential oils (basil, caraway, laurel, lemon, oregano, sage, tea, and thyme) shows that some do have the potential to increase weight gain.

Farina Khattak, the SRUC researcher who led the study, said: “One of the key benefits we found with the herbal mix was a much improved feed to gain ratio. This refers to the amount chickens eat and then how much weight they put on. With the herbal supplement the birds could eat the same amount of food yet gain more weight which could mean increased profits for producers.”

The study compared the usual feed used by commercial poultry companies with one supplemented with a herbal mix and found the latter produced chickens which grew faster and had an increased amount of breast meat.

The research was carried out at SRUC’s Avian Research Centre in Ayrshire. The birds were grown from one day old until they were 42 days old, mimicking commercial rearing conditions. Birds fed the herbal mix supplemented diets were 6.6 per cent heavier than those fed the control diet and had substantially bigger portions of breast meat, from seven to 10 per cent heavier than the control birds.

The herbal mix – Tecnaroma Herbal Mix PL – trialled by the researchers has been developed by Italian feed company, Tecnessenze, and is available worldwide.

The Avian Science Research Centre (ASRC) specialises in contract research for the government and private sector and provides the focus for SRUC's avian-related research, technology transfer and education.