Effect of essential oils of Zataria multiflora on in vitro rumen fermentation, protozoal population, growth and enzyme activity of anaerobic fungus isolated from Mehraban sheep

Effect of essential oil blends and a nonionic surfactant on rumen fermentation, anti-oxidative status, and growth performance of lambs

This study aimed to evaluate the effect of essential oils (OEO; XEO) and an emulsifier on rumen fermentation, anti-oxidative status, and the growth performance of lambs. A finishing study was conducted using 35 females and 35 males Suffolk × Canadian Arcott crossbreed lambs, fed a 16:84 forage:concentrate pelleted barley-based with either Control; Bovatec (0.018% Bovatec); Emulsifier (0.25% of Emulsifier); OEO (0.11% of blend 1); XEO (0.0125% of blend 2); OEO + Emulsifier; or XEO + Emulsifier. The rumen fluid of all lambs was sampled via stomach tubing to measure ruminal pH, volatile fatty acid (VFA), and NH3 concentrations and enumerate protozoa. Ruminal pH, molar proportions of individual VFA (except for acetate), and ammonia concentration were similar among treatments. The acetate and total VFA concentrations were lower (P = 0.03) for lambs receiving OEO, while protozoa numbers were increased (P = 0.01). No changes were observed in blood glutathione peroxidize or total superoxide dismutase, but there was a tendency for a reduction in thiobarbituric acid reactive substances in lambs fed diets containing OEO or XEO. No differences among diets were observed in coccidia oocyst counts (OPG) in feces, however, the prevalence of coccidia in lambs was reduced (Cramer's V = 0.081) with OEO. Lambs fed OEO had the highest (P < 0.01) dry matter intake (DMI) (1.48 kg/d), whereas those fed XEO had the lowest (1.30 kg/d). Average daily gain (ADG), feed conversion (DMI/ADG), and carcass measurements (hot carcass weight, carcass dressing percentages) were not affected by EO or EM. Results from this study suggest that EO may alter rumen fermentation and protozoa counts and increase DMI. However, these responses did not appear to be enhanced by Emulsifier as its inclusion with essential oils did not enhance fermentation or growth responses.

Sustainable impact of pulp and leaves of Glycyrrhiza glabra to enhance ruminal biofermentability, protozoa population, and biogas production in sheep

The aim of this study was to evaluate the effect of pulp and leaves of Glycyrrhiza glabra to reduce the ruminal biogas production in sheep. Five experimental diets of two levels of Glycyrrhiza glabra pulp (GGP) and Glycyrrhiza glabra leaves (GGL) at 150 and 300 g/kg dry matter (DM) were assessed for biogas production and fermentation parameters. Diets were control (diet without GGP or GGL), GGP15 (diet contains GGP at 150 g/kg DM), GGP30 (diet contains GGP at 300 g/kg DM), GGL15 (diet contains GGL at 150 g/kg DM), and GGL30 (diet contains GGL at 300 g/kg DM). Inclusion of 150 and 300 g/kg GGP and 300 g/kg GGL decreased (P < 0.0001) asymptotic biogas production (A), fermentation rate (μ), biogas production at 24 h of incubation (GP24), apparent degraded substrate (ADS), in vitro organic matter disappearance (OMD), and metabolizable energy (ME). Microbial protein biomass (MP) was improved (P = 0.003) by GGP15, GGL15, and GGL30 versus control. Total VFAs (P = 0.003), acetate (P = 0.009), and butyrate (P = 0.002), CH4 (mmol and mL/g OMD), CO2 (mmol and mL/g OMD) (P = 0.0003 and P = 0.0002, respectively), were decreased in GGP15, GGP30, and GGL30 diets versus control. Acetate to propionate ratio (Ac/Pr) was decreased (P = 0.038) in GGL30 diet compared to other diets. Replacing GGP and GGL with alfalfa reduced NH3-N concentration (P = 0.022), total protozoa (P < 0.0001), Isotricha spp. (P = 0.047), Dasytricha spp. (P = 0.067), subfamilies of Entodiniinae (P < 0.0001), and Diplodiniinae (P = 0.06). Results suggested that inclusion of dietary GGL at 150 g/kg dry matter positively modified some rumen parameters such as microbial protein production, protozoa population, and NH3-N concentration, which may be useful economically in ruminant animals and decreasing of environmental pollution.

Potentials of patchouli (Pogostemon cablin) essential oil on ruminal methanogenesis, feed degradability, and enzyme activities in vitro

The effects of patchouli essential oil (PEO) as an alternative to antibiotics on ruminal methanogenesis, feed degradability, and enzyme activities were evaluated. The basal substrate was incubated without additives (control, CTL) and with monensin (MON, 6 μM/g DM) or patchouli essential oil (PEO, 90 μg/g DM) for 24 h. In three different runs, the gas production (GP) was recorded at 2, 4, 8, 12, and 24 h of incubation using a semi-automatic system. The results revealed that MON had decreased (P < 0.05) the net GP and CH₄ production and digestible and metabolizable energy relative to PEO supplementation. The in vitro truly degraded organic matter was not influenced by PEO application, while was reduced (P = 0.027) with MON. Both PEO and MON had similar reducing effect on the activity of carboxymethylcellulase (P = 0.030), in vitro truly degraded neutral detergent fiber (P = 0.010), NH₃-N concentrations (P = 0.012), acetate proportion (C2, P = 0.046), C2 to C3 ratio (P = 0.023), and total protozoal count (P = 0.017). Both additives recorded similar elevating potential on the α-amylase activity (P = 0.012), propionate (C3) proportion (P = 0.011), and microbial protein (P = 0.034) compared with CTL. Effects of MON and PEO on ruminal feed degradability, microbial enzyme activities, and total protozoa counts may be responsible for modifying rumen fermentation ecology. Addition of PEO may act as a desirable alternative rumen modifier for MON in ruminant diets.

The effect of essential oils of Zataria multiflora and Mentha spicata on the in vitro rumen fermentation, and growth and deaminative activity of amino acid-fermenting bacteria isolated from Mehraban sheep

Gas (CO2 and CH4) and ammonia production in the rumen represent major sources of lost carbon and nitrogen, respectively. The essential oils of some plants have been shown to decrease gas and ammonia production by selectively inhibiting rumen microbes. Particularly, those of Zataria multiflora (ZEO; thymol 21%, carvacrol 32%) and Mentha spicata (SEO; carvone 55%) were evaluated in vitro as ruminant-feed additives. The experiments employed mixed rumen microbes and a hyper-ammonia-producing bacterium (HAP) isolated from the rumen of a Mehraban sheep. Both ZEO and SEO decreased in vitro fibre digestibility and also gas production by mixed rumen microbes that were fermenting a typical growing-lamb diet. ZEO decreased ammonia concentration in mixed culture of rumen microbes, but SEO exerted the opposite effect. A bacterial isolate (MT8) was obtained from the rumen of a Mehraban sheep, and the 16S rRNA gene sequence indicated that it was most closely related to Clostridium bifermentans. Isolate MT8 exhibited rapid ammonia production when peptides were the growth substrate, which indicated that MT8 was a HAP. Both oils inhibited the growth and ammonia production of isolate MT8. However, ZEO decreased ammonia production at lower doses, and to a greater degree, than did SEO. These results indicated that both essential oils could potentially be used to modulate rumen fermentation. The detrimental effects on fibre digestion could be problematic in high-forage diets, and this requires further investigation. Isolate MT8 is the first described HAP from the Mehraban sheep rumen. Results on ammonia production by isolate MT8 and mixed rumen microbes indicate differential mode of action of each oil on this parameter.