The effect of plant and essential oils of Mentha longoforia on in vitro ruminal fermentation parameters, methane production and protozoa population of goat

The aim of this study was to evaluate the effects of Mentha longofolia plant (MLP) and its essential oils (MLE) on ruminal fermentation and protozoa population in goat. The MLP at six levels 0, 25, 35, 55, 75 and 100 mg/30 ml, and the essential oil at six levels 0, 1700,3000,6700,8300 and 10000 mg/L plus monensin (as positive control, 50 mg and dissolved in ethanol) added to rumen fluid respectively. The in vitro gas production was conducted by compiled randomized design with five replications for each treatment. The gas production was decreased at levels of 75 and 100 mg of MLP (p˂0.001). Organic matter degradability was reduced (p˂0.001) at 75 and 100 mg levels respectively of MLP compared to control. Ammonia nitrogen concentration was decreased (p˂0.001) at all levels of MLP compared with control and monensin treatments. However, partition factor was increased (p˂0.001) only at 100 mg of MLP. The efficiency of microbial protein production was increased (p˂0.001). The metabolisable energy and net energy lactation were decreased (p˂0.001) by inclusion MLP at two level of 75 and 100 mg as total volatile fatty acids reduced, compared with control treatment. The total protozoa and subfamily of Entodinninea were declined (p˂0.001) at all levels of MLP compared with control and positive control treatments. The parameters of methane production, ammonia N and protozoa population were reduced (p˂0.001) by all levels of MLE. The efficiency of microbial protein production was enhanced (p˂0.001).Results suggest that the methane gas production, ammonia N and protozoa populations were reduced in both MLP and MLE and improved partition factor and microbial protein production.