Effect of Cyclotrichium niveum Essential Oil on Rumen Microbial Fermentation and in vitro Digestibility of Barley


Şahan Z., Tel A. Z., Kutay H.

Journal of Tekirdag Agricultural Faculty, vol.18, no.1, pp.138-145, 2021 (Scopus)

Abstract

The digestibility of feed in ruminants and the volatile fatty acids (VFA) resulting from digestion directly affect

animal performance. It has long been studied on the use of essential oils as an alternative to antibiotics to ensure

optimum conditions for the rumen environment. Cyclotrichium niveum (mountain mint) essential oil is rich in

antimicrobial agents. In this study different doses (0, 50, 100 and 150 mg/L of culture fluid) of Cyclotrichium

niveum essential oil was incubated 24 hours with barley in diluted ruminal fluid takes from fistulated cows fed

with a 40:60 concentrate:forage diet in order to assess the effects on rumen microbial fermentation and in vitro

true digestibility of barley. True digestibility of barley was determined in ANKOM Daisy Incubator. All doses of

Cyclotrichium niveum significantly (P<0.001) decreased the in vitro dry matter (DM), organic matter (OM),

neutral detergent fiber (NDF) digestibility of barley. Cyclotrichium niveum essential oil negatively affected endproducts

of rumen fermentation; the value of the measured rumen volatile fatty acids (VFA: acetate, propionate,

butyrate, isobutyric acid, valerate and isovalerate) significantly decreased compared to the control group (P<0.001).

Carbon dioxide and methane gases created as a result of incubation in rumen fluid were calculated using volatile

fatty acid values formed in rumen fluid. The addition of Cyclotrichium niveum essential oil significantly reduces

the CO2 in rumen fluid (P<0.001). Methane (CH4) gas from rumen fluid was significantly decreased in treatment

groups compared the control group (P <0.001) While end-products of rumen fermentation parameters significantly

decreased with all doses of Cyclotrichium niveum essential oil, rumen pH has increased (P<0.05). The results show

that when the Cyclotrichium niveum essential oil incubated with barley significantly inhibited the rumen microbial

activity and overall fermentation process of rumen.