Evaluating Orego-Stim® Antibacterial Activity in Comparison to Competitor Products


  • Phytogenics (plant-based feed additives) have been suggested as suitable natural alternatives to help reduce the need for antimicrobials (Lillehoj et al., 2018).
  • This work is part of the Anpario’s 4R approach (Review, Reduce and Replace antimicrobials Responsibly) which helps manage gut health and support healthier livestock through the use of natural products.
  • Orego-Stim proved more effective than other commercially available phytogenics, producing a larger zone of inhibition against a specific resistant Escherichia coli (E. coli) strain.



  • The antibacterial effect of a product can be easily compared using a zone of inhibition test. This highlights the sensitivity of a known bacteria to multiple products.
  • The larger the zone of inhibition, the more effective the product is against the chosen bacteria.
  • Orego-Stim is a high quality, plant based eubiotic, containing 100% natural oregano essential oil.


Trial Design

An independent laboratory trial was carried out to compare the antibacterial effect of five phytogenic products on multi-drug resistant E. coli. Standardised Mueller Hinton plates were sourced pre-impregnated with the bacterium and the five treatments (Table 1) applied as per the laboratory standard protocol. Following incubation at room temperature for 24 hours each zone of inhibition on the plate was measured to determine antibacterial activity. 

Orego-Stim natural oregano essential oil product antibacterial activity compared to competitor products


Orego-Stim natural oregano essential oil shown superior antibacterial activity compared to competitor products
  • Orego-Stim showed an extensive 10mm zone of inhibition on the cultured agar plate. This was at least 100% better than any of the other products tested (Fig. 1).
  • The largest zone of inhibition recorded out of the five products tested was for Orego-Stim (Fig. 2).
  • Orego-Stim has been shown to be a highly effective, 100% natural product which can be effective in helping to inhibit resistance bacterial growth. 

Orego-Stim is Anpario's 100% natural high quality oregano essential oil (OEO) additive, available in both liquid and powder. 

Orego-Stim - 100% Natural Oregano Essential Oil Additive - highly effective in helping to inhibit bacterial growth

Suitable for all poultry (chickens, ducks, turkeys), game birds, pigs, dairy and beef calves, fancy and racing pigeons, as well as equine.


  • Herby and aromatic encourages feed intakes; 
  • Supports digestive health and nutrient absorption;
  • Rich in antioxidants to maintain health and well-being.

Leave a comment

Please note, comments must be approved before they are published

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.