The effect of peppermint (Mentha piperita) on ruminal physiological parameters in Lori sheep
Mentha piperita is a medicinal plant in traditional systems of medicine. The major active constituent is the volatile oil, which contains menthol, neomenthol, and isomenthol. Peppermint has been reported to have antimicrobial and pharmacological effects in monogastric animals in vivo and in vitro, so those effects may also affect the nutrition and physiology in sheep. The aim of this research was to investigate the effect of peppermint feeding on ruminal physiological parameters in Lori sheep.
Five clinically healthy sheep (bodyweight, 38±2kg; 6 month to 1 year old; male) were successfully rumen-cannulated. Sheep were housed in stalls and had free access to alfalfa hay, concentrate and water. The experimental period was 15 days, with the first seven days allotted to adaptation and the last 8 days used as the test period. Prior to peppermint feeding (experiments days), rumen samples were gathered at 0.5, 1, 2 and 4 hours after feeding (alfalfa hay and concentrate), to determine rumen pH, microflora, protozoa, sedimentation rate and reduction-oxidation potential for 3 days as control. Experiments days commenced by additions of peppermint to rumen (via rumen cannula) at a dose of 0.5g/kg b.w. peppermint in the first day and 0.1g/kg b.w. increment each day up to eight days. Finally the maximum amount of 1.2g/kg b.w. peppermint was fed to each sheep. amples of rumen were collected at 0.5, 1, 2 and 4 hours after addition of peppermint. The ruminal peppermint addition led to the following results: rumen pH increased significantly (p<0.5) at 4 and 5 days, sedimentation rate increased significantly (p<0.5) at 2 and 6 days, reduction-oxidation potential increased significantly (p<0.5) at 4 and 7 days, protozoa and microflora had no significant changes compared to control. The aforementioned changes were within the stable condition range. These results suggest that feeding peppermint to Lori sheep had little effect on their ruminal physiological parameters.