Effect of peppermint oil and its microemulsion on necrotic enteritis in broiler chickens

is one of the multiple drug-resistant intestinal pathogens causing necrotic enteritis disease, leading to great economic losses in poultry farms. This study aimed to evaluate the potential use of peppermint oil and its microemulsion (ME) as an alternative to antibiotics to control necrotic enteritis in broiler chickens. Peppermint oil ME formulation (15% oil/water) was prepared and characterized by zeta potential, Fourier transform infrared, high-resolution transmission electron microscopy, and liquid chromatography-mass spectrometry (LC-MS/MS). The minimal inhibitory concentrations of the peppermint oil and its ME were investigated. A total of 80 commercial one day old Arbor Acres broiler chickens were randomly assigned to four groups of 20 birds each. The four groups were the negative control, positive control, peppermint oil (0.5 mL/mL water/10 days old), and its ME (0.25 mL/mL water/10 days old) groups. was orally provided at concentration of 1×10 CFU/mL on days 14, 15, and 16. Clinical signs and mortality were observed daily. Growth performance, gross lesions and cecal samples were investigated and examined on days 21, 28, and 35. Peppermint oil ME formulation has a polydispersity index, zeta potential and droplet size of 0.234, -24 mV±4.19, and 29.96±1.56 nm, respectively. LC-MS/MS analysis of oil and ME revealed common presence of phenolic compounds such as rosmorinic (360.31 g/mol), chlorogenic acid (354.31 g/mol), hesperidin (610.56 g/mol), and luteolin 7-O-β-glucuronide (462.1 g/mol). The treated groups with peppermint oil and ME showed lower lesions, mortality and colony-forming units in addition to higher growth performance (p < 0.05) compared to the positive control group. Our study suggests the potential efficacy of peppermint oil and ME in the reduction of necrotic enteritis lesions and count.