the effect of achillea millefolium and mentha pulegium essential oils on bacillus and bifidobacterium microbiota in layers

This experiment was conducted to assess the efficacy of achillea millefolium and mentha pulegium, also known as yarrow and pennyroyal essential oils on gastrointestinal microflora specifically bacillus and bifidobacterium in layers. a total number of 128 laying hens were utilized within a completely randomized design framework. the experimental treatments consisted of the following: 1. a basic diet serving as the control group; 2. a basic diet supplemented with 0.0125 ml of emulsifier, referred to as control+; 3, 4 and 5. basic diet plus 50, 100, 150 mg/kg of yarrow essential oil, respectively; 6, 7 and 8. basic diet plus 50, 100, 150 mg/kg of pennyroyal essential oil. the energy and protein content of the food rations were adjusted in accordance with the specific strain guidelines. the treatments were lasted for 6 weeks. at the end, fecal samples from each cage were collected as a composite for each treatment group to facilitate microbiological analysis. the data were classified by excel and underwent statistical analysis utilizing spss software and means were compared using duncan s method. compared to control group, there was a reduction in the number of bacillus bacteria in treated groups with yarrow and pennyroyal. however, no significant difference was found among the mentioned treatment groups. also, a rise in the population of bifidobacterium in the treatment groups compared to control and control+ samples and the count by yarrow essential oil was more than the count by pennyroyal essential oil.