Effect of dietary ethanolic extraction of pennyroyal (Menthe pulegium) in comparison with an antibiotic growth promoter on blood biochemical parameters, weight of internal organs and intestinal bacterial counts in broilers

An experiment was conducted with 240 Ross broiler chicks (mixed male and female) to evaluate the effect of ethanolic extract of pennyroyal in comparison with flavomycin antibiotic growth promoter (AGP) on blood biochemical parameters, weight of internal organs and cecal bacterial counts in broilers. The experiment was conducted in a completely randomized design manner with 4 treatments, 3 replicates and 20 chicks in each replicate from 1 to 42 days of age. Treatment 1 was a control basal diet, treatment 2 was the basal diet with 0.45 % AGP and treatments 3 and 4 received 0.1 and 0.05 % pennyroyal ethanolic extract in the basal diet, respectively. The results showed that the ethanol extract of pennyroyal in both used concentrations, reduced harmful bacteria (coliforms, Salmonella and E.coli) in ceca (p<0.05)., No significant effect on the weights of internal organs was observed except for the gizzard. Ethanolic extraction of pennyroyal increased the serum cholesterol concentration and decreased the activity of ALT, when compared with control group.