Abstract

Abstract The objective of the present study was to investigate dose-response effects of the essential oil (EO) and dry extract (EX) of Satureja khuzistanica (SK) on in vitro gas production kinetics, rumen fermentation, ruminal methanogenesis and microbial protein synthesis. So, EO and EX were tested at 0 (as control); 150 (low dose); 300, 450 (intermediate doses) and 600 mg/L (high dose). The gas produced over 24 h of incubation (GP24) decreased linearly with both EO and EX dosages (P<0.01). In vitro methane production was reduced by both EO (14–69%, depending on the included dose) and EX (7–58%). Microbial protein (MP) as well as the efficiency of microbial protein synthesis (EMPS) were improved by EO (18.8–49.8% and 20.4–61.5% for MP and EMPS, respectively) and to a lesser extent by EX (8.3–25.7% and 4.6–24.2% for MP and EMPS, respectively). Ammonia concentration was dropped in linear and quadratic manners with EO (P<0.05), and linearly with EX dosages (P<0.01). EO and EX exhibited depressive effects (in linear and quadratic (P<0.05), and linear manners (P<0.01), respectively) on total protozoa count. A mixed linear and quadratic effect was observed from both EO and EX on total VFA concentration (P<0.01). Total VFA concentration increased at 300 mg/L of EX, but decreased at high dose of both EO and EX. The acetate proportion increased with EO intermediate and high dosages, but it decreased at the expense of propionate at low and intermediate doses of EX. In total, these findings confirmed previous research on the great capacity of plant-based feed additives in positively modulating rumen fermentation that their effects may vary depending on the doses used. Specifically, these results suggest that EO and EX have high potentials to improve rumen functions at intermediate doses, which needs to be confirmed by in vivo experiments.

Highlights

  • The objective of the present study was to evaluate the effects of using different levels the essential oil or dry extract of Satureja khuzistanica (SK) on in vitro ruminal fermentation, microbial protein synthesis and methane production

  • Based on the results of Gas Chromatography-Mass Spectrometry (GC-MS) analysis, carvacrol, γ-terpinene, p-cymene and αterpinene were the major components of EO accounting for 715.7, 88.3, 58.6 and 37.6 g/kg of total essential oil

  • Similar to EO, EX exhibited a linear depressive effect (P0.05)

Read more

Summary

Objectives

The objective of the present study was to investigate dose-response effects of the essential oil (EO) and dry extract (EX) of Satureja khuzistanica (SK) on in vitro gas production kinetics, rumen fermentation, ruminal methanogenesis and microbial protein synthesis. The objective of the present study was to evaluate the effects of using different levels the essential oil or dry extract of SK on in vitro ruminal fermentation, microbial protein synthesis and methane production

Methods
Results
Discussion
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call