In this study, the effects of seven pure plant secondary metabolites (PSMs) on rumen fermentation, methane (CH4 ) production and rumen bacterial community composition were determined. Two in vitro trials were conducted. In trial 1, nine concentrations of 8-hydroxyquinoline, α-terpineol, camphor, bornyl acetate, α-pinene, thymoquinone and thymol were incubated on separate days using in vitro 24-hr batch incubations. All compounds tested demonstrated the ability to alter rumen fermentation parameters and decrease CH4 production. However, effective concentrations differed among individual PSMs. The lowest concentrations that reduced (p < .05) CH4 production were as follows: 8 mg/L of 8-hydroxyquinoline, 120 mg/L of thymoquinone, 240 mg/L of thymol and 480 mg/L of α-terpineol, camphor, bornyl acetate and α-pinene. These concentrations were selected for use in trial 2. In trial 2, PSMs were incubated in one run. Methane was decreased (p < .05) by all PSMs at selected concentrations. However, only 8-hydroxyquinoline, bornyl acetate and thymoquinone decreased (p < .05) CH4 relative to volatile fatty acids (VFAs). Based on denaturing gradient gel electrophoresis analysis, different PSMs changed the composition of bacterial communities to different extents. As revealed by Ion Torrent sequencing, the effects of PSMs on relative abundance were most pronounced in the predominant families, especially in Lachnospiraceae, Succinivibrionaceae, Prevotellaceae, unclassified Clostridiales and Ruminococcaceae. The CH4 production was correlated negatively (-.72; p < .05) with relative abundance of Succinivibrionaceae and positively with relative abundance of Ruminococcaceae (.86; p < .05). In summary, this study identified three pure PSMs (8hydroxyquinoline, bornyl acetate and thymoquinone) with potentially promising effects on rumen CH4 production. The PSMs tested in this study demonstrated considerable impact on rumen bacterial communities even at the lowest concentrations that decreased CH4 production. The findings from this study may help to elucidate how PSMs affect rumen bacterial fermentation.

• Keywords
• Ion Torrent, alkaloid, essential oil, methane, rumen bacteria, rumen fermentation,
• MeSH
• Rumen metabolism   microbiology   MeSH
• Diet veterinary   MeSH
• Nitrogen metabolism   MeSH
• Fermentation * MeSH
• Bacterial Physiological Phenomena MeSH
• Fatty Acids, Volatile metabolism   MeSH
• Poaceae metabolism   MeSH
• Methane biosynthesis   MeSH
• Cattle MeSH
• Animals MeSH
• Check Tag
• Cattle MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Nitrogen MeSH
• Fatty Acids, Volatile MeSH
• Methane MeSH

The degradation of red clover isoflavones was studied in vitro using a rumen fluid buffer system. Various amounts of red clover extract (5-75 mg) together with hay or concentrate-rich diet were added to 40 ml of rumen fluid obtained from non-lactating and lactating dairy cows, respectively, and incubated for 0, 3, 6, 12 or 24 hr. Following incubation, concentrations of daidzein, genistein, formononetin, biochanin A and equol were determined in the samples. After 3 hr of incubation, isoflavone metabolism and equol production could be observed. The results obtained indicate that hay diet provides better conditions for isoflavone metabolism, as concentrations of daidzein, formononetin and biochanin A were higher in incubations based on the concentrate-rich diet and the production of equol was higher in incubations based on the hay diet. Furthermore, in incubations with higher amounts of added clover extract, a decrease in equol production was observed. Further studies are needed to clarify the role of adaptation of rumen microflora on isoflavone degradation kinetics and to clarify the interrelationship between various dietary factors, rumen microbiota and isoflavones. The knowledge of isoflavone metabolism kinetics in dependence on studied factors will be useful for the optimization of feeding dose.

• Keywords
• Isoflavone, diet, equol, metabolism, rumen fluid,
• MeSH
• Rumen MeSH
• Diet veterinary   MeSH
• Isoflavones * MeSH
• Lactation MeSH
• Cattle MeSH
• Trifolium * MeSH
• Animals MeSH
• Check Tag
• Cattle MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Isoflavones * MeSH

The aim of this study was to determine the degradation of dietary isoflavones in rumen fluid under 2 feeding regimens. The experiments were performed in vitro using a rumen fluid buffer system. The rumen fluid was taken from cows fed either a hay diet or a concentrate-rich diet (the diet consisted of 34.6% maize silage, 17.6% haylage, 12.8% alfalfa hay, and 35.0% supplemental mixture on a dry matter basis). As a source of isoflavones, 40% soybean extract (Biomedica, Prague, Czech Republic) at levels of 5, 25, 50, and 75 mg per 40 mL of rumen fluid was used. Samples of soybean extract were incubated in triplicate at 39°C for 0, 3.0, 6.0, 12.0, and 24.0 h in incubation solution. The metabolism of daidzein and genistein was faster under concentrate-rich diet conditions. In general, production of equol started after 3 to 6 h of incubation and reached the highest rate after approximately 12 h of incubation regardless of the type of diet or concentration of extract. In most of the experiments, production of equol continued after 24 h of incubation. Generally, equol production was greater under the hay diet conditions. Furthermore, experiments with higher amounts of added soybean extract revealed possible inhibitory effects of high levels of isoflavones on the rumen microflora.

• Keywords
• cattle diet, equol, isoflavones, rumen,
• MeSH
• Rumen metabolism   MeSH
• Diet MeSH
• Animal Nutritional Physiological Phenomena physiology   MeSH
• Isoflavones administration & dosage   analysis   metabolism   MeSH
• Animal Feed MeSH
• Lactation MeSH
• Silage MeSH
• Cattle MeSH
• Animals MeSH
• Check Tag
• Cattle MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Isoflavones MeSH

The effect of O-ethyl-S-(2-diisopropylaminoethyl) methylthiophosphonate on rumen bacteria and rumen protozoa was investigated in sheep (after premedication with clinoptilolite-rich zeolite and without that premedication). In control animals a decrease in the total concentration of rumen protozoa was observed 3-7 d after intoxication (particularly in small and large ones). In clinoptilolite-rich-zeolite-treated animals only a slight decrease in protozoan numbers occurred during the first hours after the intoxication. Similarly, in every category of rumen bacteria marked differences between the groups were recorded, particularly in concentration of lipolytic bacteria. The results suggest some protective effect of clinoptilolite-rich zeolite for rumen microbiota against the organophosphate poison.

• MeSH
• Rumen drug effects   microbiology   parasitology   MeSH
• Bacteria drug effects   isolation & purification   MeSH
• Eukaryota drug effects   isolation & purification   MeSH
• Organothiophosphorus Compounds toxicity   MeSH
• Sheep MeSH
• Colony Count, Microbial MeSH
• Zeolites pharmacology   MeSH
• Animals MeSH
• Check Tag
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• clinoptilolite MeSH Browser
• Organothiophosphorus Compounds MeSH
• VX MeSH Browser
• Zeolites MeSH

In experiments on six sheep fed on a low protein diet (6.2 g N/day), it was found that the urease activity of the rumen fluid did not change significantly in the first 6 hours after feeding and that it ranged from 45 to 75 nkat.ml-1. The major portion was bound to the bacterial fraction and formed about 70% of total rumen fluid activity. Urease activity determined in food particles with adherent bacteria removed from the rumen before and 3 and 6 hours after feeding ranged from 20 to 26 nkat.g-1 food (wet weight), and on rumen wall samples with adherent bacteria from 30 to 800 nkat per 2.5 cm2 tissue. Again, no significant changes correlated to the time after feeding were found. The results show that urease activity in the sheep rumen is localized on food particles and on rumen wall epithelium with adherent bacteria, as well as in the rumen fluid.

• MeSH
• Ammonia metabolism   MeSH
• Rumen enzymology   microbiology   MeSH
• Bacteria enzymology   MeSH
• Time Factors MeSH
• Sheep MeSH
• Urease metabolism   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Ammonia MeSH
• Urease MeSH

The addition of Na-lactate (50-150 mmol/l) to media with glucose had only marginal effect on the growth of rumen lactate-producing bacteria at pH between 6.5 and 5.8. Butyrivibrio fibrisolvens was somewhat more sensitive to external lactate than Streptococcus bovis, Lactobacillus fermentum and Selenomonas ruminantium. It can be concluded that rumen lactate producers, which proliferate at the onset of rumen lactic acidosis, are not influenced by the lactate accumulation, except some non-specific osmotic effects.

• MeSH
• Rumen microbiology   MeSH
• Bacteroidaceae drug effects   growth & development   metabolism   MeSH
• Glucose metabolism   MeSH
• Hydrogen-Ion Concentration MeSH
• Culture Media MeSH
• Lactobacillus drug effects   growth & development   metabolism   MeSH
• Lactates biosynthesis   pharmacology   MeSH
• Osmotic Pressure MeSH
• Sheep MeSH
• Streptococcus bovis drug effects   growth & development   metabolism   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Glucose MeSH
• Culture Media MeSH
• Lactates MeSH

Three strains of rumen treponemes were isolated and partially characterized. The strains differed significantly one from another in morphology, fermentation characteristics and plasmid profiles. Their genetic variability was assayed using DNA-based molecular approaches. Easily differentiated ARDRA (amplified ribosomal DNA restriction analysis) patterns indicated that the strains represent different bacterial species.

• MeSH
• Rumen microbiology   MeSH
• Phenotype MeSH
• Fermentation MeSH
• Sheep microbiology   MeSH
• Plasmids MeSH
• RNA, Ribosomal, 16S classification   MeSH
• Treponema classification   genetics   isolation & purification   metabolism   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• RNA, Ribosomal, 16S MeSH

The concentrations of volatile fatty acids and the development of rumen epithelium and microflora adhered to rumen wall in suckling lambs were observed. Total VFA concentration increased with age. The differences between the 1st (28.5 mmol.l-1) and 4th week of age (78.7 mmol.l-1) and between 6th (82.1 mmol.l-1 and 10th week of age (117.4 mmol.l-1) were significant (p < 0.01). The highest molar proportion of acetic acid (71.2 mol%) was observed in 1 week-old lambs and the highest molar proportion of propionic acid in 6 week-old lambs (20.8 mol%). Length and surface characteristics of papillae changed dramatically over the 10-week period. In samples from 1-week and 4-week-old lambs, the papilla surface was relatively smooth and epithelial cells were relatively thin and flat. In samples from 6-week and 10-week-old lambs the tissue topography was typically rough. In the 1-week-old lambs the cocci, single rods and short rods in pairs were present at very low population levels. At 4 weeks the epimural community became notably more complex and bacteria were present at a higher population level. The dominant morphotype at 6 weeks was a rod-shaped end-on attached bacterium. The epimural microflora became the most complex at 10 weeks.

• MeSH
• Rumen growth & development   metabolism   microbiology   ultrastructure   MeSH
• Bacteria growth & development   ultrastructure   MeSH
• Bacterial Adhesion MeSH
• Epithelium growth & development   microbiology   ultrastructure   MeSH
• Animals, Suckling growth & development   metabolism   MeSH
• Fatty Acids, Volatile biosynthesis   MeSH
• Microscopy, Electron, Scanning MeSH
• Sheep growth & development   metabolism   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Fatty Acids, Volatile MeSH

Rumen ciliate protozoa intensively engulf bacteria. However, their ability to utilize murein which is the main polysaccharide of bacterial cell wall has hardly been recognized. The present study concerns the ability of the rumen protozoa Diploplastron affine to digest and ferment murein. The ciliates were isolated from the rumen fluid and grown in vitro or inoculated into the rumen of defaunated sheep. The results of long-term cultivation of protozoa showed a positive correlation between their number and murein content in the culture medium. It was also found that bacteria-free D. affine ciliates incubated with or without murein produced volatile fatty acids at the rate of 12.3 and 8.7 pmol/h per protozoan, respectively, acetic, butyric and propionic acids being the three main acids released to the medium. Enzyme studies performed with the use of protozoan cell extract prepared from bacteria-free ciliates degraded murein at a rate of 25 U/mg protein per h; two mureinolytic enzymes were identified by zymographic technique in the examined preparation.

• MeSH
• Rumen parasitology   MeSH
• Ciliophora isolation & purification   metabolism   MeSH
• Culture Media chemistry   MeSH
• Fatty Acids, Volatile metabolism   MeSH
• Sheep MeSH
• Peptidoglycan metabolism   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Culture Media MeSH
• Fatty Acids, Volatile MeSH
• Peptidoglycan MeSH

Chitinolytic systems of anaerobic polycentric rumen fungi of genera Orpinomyces and Anaeromyces were investigated in three crude enzyme fractions - extracellular, cytosolic and cell-wall. Endochitinase was found as a dominant enzyme with highest activity in the cytosolic fraction. Endochitinases of both genera were stable at pH 4.5-7.0 with optimum at 6.5. The Orpinomyces endochitinase was stable up to 50 degrees C with an optimum for enzyme activity at 50 degrees C; similarly, Anaeromyces endochitinase was stable up to 40 degrees C with optimum at 40 degrees C. The most suitable substrate for both endochitinases was fungal cell-wall chitin. Enzyme activities were inhibited by Hg(2+) and Mn(2+), and activated by Mg(2+) and Fe(3+). Both endochitinases were inhibited by 10 mmol/L SDS and activated by iodoacetamide.

• MeSH
• Anaerobiosis MeSH
• Rumen metabolism   microbiology   MeSH
• Chitin metabolism   MeSH
• Chitinases * chemistry   metabolism   MeSH
• Chytridiomycota classification   enzymology   growth & development   MeSH
• Fungal Proteins genetics   MeSH
• Hydrogen-Ion Concentration MeSH
• Neocallimastigales classification   enzymology   growth & development   MeSH
• Enzyme Stability MeSH
• Temperature MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Chitin MeSH
• Chitinases * MeSH
• Fungal Proteins MeSH