Table 3.

Effects of essential oils and aromatic plants on the microflora in swine and poultry

Feed additive	Dose, g/kg	Species	Measured responses	References
Herbal extracts	7,500	Weaned pigs	Reduced coliform bacteria counts in fecal; less diverse of microbiota in ileal digesta base on PCR-DGGE	Namkung et al. [7]
EO blend	50-150	Weaned pigs	Increased Lactobacillus and decreased E. coli counts in feces	Li et al. [16]
EO blend	1,000	Weaned pigs	Increased Lactobacillus counts	Zhang et al. [17]
Chinese medicinal herbs	1,000/3,000	Weaned pigs	Increased Lactobacilli counts in ileum and decreased Coliform counts in colon	Huang et al. [18]
EO blend	100	Weaned pigs	Reduced E. coli and total aerobic bacteria in the rectum; increased Lactobacilli to E. coli ratio in colon	Li et al. [19]
Phytogenic additive	50-150	Weaned pigs	Microbial counts in feces (aerobes, gram negatives, anaerobes and lactobacilli) didn’t change	Muhl and Liebert [48]
EO blend	300	Broiler	Decreased intestinal Clostridium, but no effect on total organisms, Streptococcus, Lactobacillus and Coliforms	Kirkpinar et al. [26]
EO	100	Broiler	Increase in the mean numbers of bacterial species in the ileal content	Amerah et al. [27]
EO blend	1,000	Broiler	No change in cecal and fecal Coliforms, Lactobacillus, C. perfringens and total anerobes	Cross et al. [28]
Oregano EO	300-1,200	Broiler	Decreased cecal E.Coli but no effect for 1200 ppm; no effect on cecal Lactobacilli	Roofchaee et al. [29]
EO	125	Broiler	No change in cecal total bacteria, Lactobaccilli, Enterococci, Coliforms or Salmonellae colonization.	Hong et al. [30]
EO blend	150-500	Broiler	Decreased crop Salmonella but no effect for 150 ppm; no effect on cecal Salmonella	Alali et al. [31]
Thymol/EO	30	Broiler	Increased cecal Lactobaccilli and decreased Coliform but no effect on crop and ileum	Ginnenas et al. [35]
Oregano EO	300	Broiler	Lower bloody diarrhea, lesion score and oocyst numbers compared to control (E. tenella challenge)	Ginnenas et al. [49]
Oregano	330	Broiler	Decreased C. perfringens counts in cecum	Waldenstedt et al. [50]
EO blend	100	Broiler	Reduction of C. perfringens concentration in the jejunum and colon	Mitsch et al. [51]
Plant extract	100	Broiler	Reduction of E. coli, C. perfringens and fungi and increase of Lactobacillus	Jamroz et al. [52]
Oregano EO	0.5-1.25	Broiler	Oregano EO exhibited a strong bactericidal effect against Lactobacilli at both doses tested	Horošová et al. [53]
EO blend	100	Broiler	Increased ileal Lactobacillus counts coupled with decreased E.Coli counts	Rahimi et al. [54]
EO	500	Broiler	Decreased cecal Staphylococci, Lactobaccilli and Enterobacteriaceae	Placha et al. [55]
EO blend	25/50	Broiler	Decreased ileo-cecal E.Coli, and no change in Lactobacilli	Jang et al. [56]