This research project began in 2005 with testing of 66
essential oils (including geraniol, eugenol, carvacrol, cinnamon
oil, clove oil and thymol) for their ability to inhibit the
growth of certain types of salmonella and E. coli.
Sixteen out of the 66 were found to have strong antimicrobial
properties. Nine were then further studied to measure
the degree of antibacterial effects and stability at low
pH (the acidity level found in pig stomachs), and to determine
whether they had any negative effect on the growth
of beneficial gut bacteria. The researchers have compared different forms of
essential oils – dry powder and liquid suspension – and have
found dry powder preferable as it is easy to store, handle and
distribute. Using dry powder also makes it easy to control
the dosage and, in addition, it can be applied to a premix,
then added to feed.
This year, the research team will carry out tests on
the antimicrobial activity of their developed essential oil
capsules when they are mixed with feed and exposed to
simulated digestion. The team will also strive to improve the
current encapsulation formula and develop new ones which
will achieve better release in the pig’s digestive system.
Animal tests will be planned if the in vitro study offers
positive results.