The effects of Mentha pulegium and Zataria multiflora on growth and carcass specifications and gut microbial count in broiler chickens

Recently, the use of medicinal plantsas growth promoters, appetizers, immunological boosters and antimicrobial substances has increased in poultry industry. In this regard, the effect of Zataria multifloraand Mentha pulegium on growth characteristics, carcass quality and gut microbial count of broiler chickens were investigated. This research was carried out in a completely randomized design with 120 broiler chickens of Ross strain in 4 different feed treatment groups and 3 replicates consisting of 10 chickens each. The treatment groups consisted of T1 (Control) fed with basic diet (without plants), T2 fed with basic diet containing 200 mg/kg of dried Mentha pulegium, T3 fed with diet containing 200 mg/kg of dried Zataria multiflora and T4 fed with diet containing a mixture of 200 mg/kg dried Zataria multiflora and 200 mg/kg dried Mentha pulegium for 6 weeks. All chickens were weighed weekly and at the end of the experimental period, growth characteristics including carcass weight, thigh weight and breast weight and intestinal microbial total count were measured in each group. The results were evaluated by one-way ANOVA and Duncan’s post-hoc test in SPSS 19. The results showed that the mean weight, the weight of thighs and breasts between treatment groups were not statistically significant but the intestinal bacterial count was decreased by these supplements (p<0.05). The maximum microbial load was observed in the control group (T1). Therefore, it can be concluded that the use of these supplements in chicken feed reduces intestinal microbial counttherefore organic and safe meat production can be expected.