Oregano (a herb related to marjoram) has been used as a food flavouring for centuries. It is also claimed that oregano has some medicinal benefits, particularly for the gastro-intestinal tract. This may be useful in poultry production, where the constant concern over the uses of antibiotics in poultry feed has stimulated the search for alternatives. Oregano may offer potential benefit as one of these alternatives (1) There is some evidence that oregano essential oil may modify the gut flora of broilers (E.coli in particular) (2) and in vitro tests suggest a beneficial effect against Salmonella typhimurium (3, 4). In one in vivo trial, there was some evidence that Inclusion of oregano essential oil in broiler grower diets significantly increased body weight gain and improved feed conversion (5).
Dr Graham Scott BSc PhD, Senior Lecturer in Poultry. , Harper Adams University, Newport, Shropshire, UK.
  1. Griggs, J.P. and Jacob, J.P. 2005. Alternatives to Antibiotics for Organic Poultry Production.  J. Appl. Poult. Res. 14:750–756
  2. Friedman, M.,  et al.. 2002. Bactericidal activities of plant essential oils and some of their isolated constituents against Campylobacter jejuni, Escherichia coli, Listeria monocytogenes, and Salmonella enterica. J. Food Prot. 65:1545–1560.
  3. Helander, I.  et al..1998. Characterization of the action of selected essential oil components on gram-negative bacteria. J. Agric. Food Chem. 46:3590–3595.
  4. Kim, J. et al. 1995. Antibacterial activity of some essential oil components against five foodborne pathogens. J. Agric. Food Chem. 43:2839–2845.
  5. 5 Amir, R, et al.. 2011 Effect of dietary oregano (Origanum vulgare L.) essential oil on growth performance, cecal microflora and serum antioxidant activity of broiler chickens. African Journal of Biotechnology Vol. 10(32), pp. 6177-6183