Evaluation of lemon peel essential oil on fecal microbial diversity of tropical Holstein dairy cows

Aims: This study was aimed to determine the effects of adding lemon peel essential oil (EO) as a feed additive to change fecal microbial diversity in tropical Holstein dairy cows. Methodology and results: This study used 12 mid-lactation Friesian Holstein tropical dairy cows with an average milk production of 6.97 ± 0.77 kg/head/day and a body weight of 426.23 ± 11.83 kg, coefficient of variation (CV=6.5%). The doses of lemon peel EO used for each head/day were as follows: S1=0 mL, S2=2.50 mL and S3=5.00 mL. Parameters consisted of an abundance of fecal microbes in phylum and genus levels. Then, the data were analyzed using descriptive quantitative analysis. Lemon peel essential oil with the main component limonene increased the relative population of the Firmicutes phylum at a dose of 5 mL/head/day but decreased the population of the Bacteriodetes phylum. The 2.5 mL/head/day dose has a relatively similar population with controls in Firmicutes and Bacteriodetes phyla. Adding lemon peel essential oil at doses of 2.5 and 5 mL/head/day reduced the population of Prevotellaceae compared to the control. Conclusion, significance and impact of study: This study concluded that a lemon peel EO dose of 5 mL/head/day affects the microbial abundance of Prevotella in the feces of tropical Holstein dairy cows with proteolytic activities. This research impacts increasing milk production due to the inhibition of Prevotella , a proteolytic bacterium.