K. Mihaliková

The Effects of Organic Selenium Supplementation on the Rumen Ciliate Population in Sheep

The effect of selenium supplementation on the rumen protozoan population of sheep was demonstrated. Both the total and generic counts of rumen ciliates in sheep fed a diet with basal Se content (70 µg/kg dry matter) were compared to those of animals given feed supplemented with inorganic (disodium selenite) or organic Se (selenized yeast) (310 µg/kg dry matter). The genera ofEntodinium, Isotricha, Dasytricha, Ophryoscolex, Diploplastron andPolyplastron occurred in all sheep except for the control, in whichOphryoscolex was not observed. The population ofOphryoscolex caudatus f.tricoronatus was significantly higher in sheep supplemented with organic Se than in animals given inorganic Se (by 160 %). Supplementation of feed with selenized yeast induced significant growth in theDiploplastron population (by 63 %) while no change occurred in sheep given selenite. The populations ofDasytricha ruminantium andPolyplastron multivesiculatum were higher than control in both Se-supplemented groups. The ciliate population ofEntodinium spp. was not influenced by Se supplements. Our results suggest a protective effect of Se feed supplementation on the development of some rumen ciliate species in young ruminants.

The ciliate, Troglodytella abrassarti, contributes to polysaccharide hydrolytic activities in the chimpanzee colon.

Entodiniomorphid ciliates are intestinal protists inhabiting the colons of African great apes. The participation of intestinal entodiniomorphid ciliates in ape hindgut digestion has been proposed, but little data have been available to support the hypothesis. We measured the specific activities of carboxymethyl cellulase, xylanase, inulinase, and α-amylase against different polysaccharides in the feces of captive chimpanzees and evaluated the participation of the entodiniomorphid ciliate, Troglodytella abrassarti, in these activities. T. abrassarti contributed to the total fecal hydrolytic activities of CM-cellulase by 16.2%, α-amylase by 5.95%, and xylanase by 0.66%. Inulinase activity in T. abrassarti samples was not measurable at reaction conditions used. The ciliates, T. abrassarti, actively participate in the chimpanzee hindgut fermentation of fiber and starch.

Effects of prefermented cereal-derived substrates (ground barley and rye bran) enriched with fungal γ-linolenic acid on rumen fermentation parameters and lipid metabolism in vitro

Aims:  To increase rumen output of γ‐linolenic acid (GLA), we used two cereal‐derived substrates, ground barley (GB) and rye bran (RB), enriched with fungal GLA as components of feed rations. We examined their effects on rumen fermentation patterns, lipid metabolism and the ciliated protozoan population in an artificial rumen.

Tolerance of a ruminant ciliate Entodinium caudatum against mercury, copper and chromium

The effects of three heavy metal cations, mercury (II), copper (II), and chromium (VI), on the growth of the rumen ciliate Entodinium caudatum in vitro culture was studied. The E. caudatum culture was challenged by HgCl2, CuCl2, and K2Cr2O7 for a period of 4 days. The tested concentrations of mercury (II) and copper (II) were 1, 5, 10, 20, 50 mg/L and 2, 10, 20, 40 mg/L for chromium (VI) at single dose with either untreated or inhibited bacterial co-culture population. Effective metal concentrations required to reduce ciliate growth by 50% (EC50) for mercury (II), copper (II), and chromium (VI) either with untreated or inhibited bacterial co-culture population after 24 h of metal application were 24, 20, and 21 or 15, 20, and 19 mg/L, respectively. After 4 days of metal application, corresponding EC50 values for mercury (II), copper (II), and chromium (VI) were 16, 20, and 17 (with untreated bacterial population) or not determinable, 20, and 15 mg/L, respectively (with inhibited bacterial population). Increased sensitivity of E. caudatum to tested heavy metals with inhibited bacterial co-culture population indicate that the ciliate resistance to the heavy metal tested depends on detoxification abilities of rumen bacterial population.

Highly efficient galvanotaxis apparatus for cleaning and concentrating rumen ciliates

Galvanotaxis was shown to be an efficient method for cleaning and concentrating rumen ciliate protozoa whose harvesting (centrifugation of large volumes ofin vitro cultures followed by repeated washing of the sediment to remove plant debris) is time consuming. We suggested the use of a new galvanotaxis apparatus (a small-capacity two-way glass stopcock) to improve cell yield in concentrating the rumen ciliate protozoa and cleaning them from impurities. Migration of the ciliates (Entodinium caudatum, Entodinium furca monolobum andDiploplastron affine) into the cathode compartment under different electric currents (0, 5, 10, and 15 mA) and intervals (5, 10, 20, and 30 min) was evaluated. The lethal current level was 20 mA. Cell yield was 9–81 %, depending on ciliate species, migration time and current. The migration time significantly affected bothE. caudatum andD. affine. The electric current-migration time interplay was shown to be significant in bothE. caudatum andD. affine. The advantages and disadvantages of the tested apparatus were determined; the two-way glass stopcock was very convenient for both cleaning and concentrating rumen ciliatein vitro cultures by galvanotaxis.

Substrates enriched by the fungus Cunninghamella echinulata: an in vitro study of nutrient composition, sheep rumen fermentation and lipid metabolism.

Enrichment of wheat bran (WB), corn meal (CM) and barley flakes (BF) with the oleaginous fungus Cunninghamella echinulata (CE) might lead to effective use of these by‐products in ruminant nutrition. We examined their effects on rumen fermentation and lipid metabolism.

The effects of high dose of two manganese supplements (organic and inorganic) on the rumen microbial ecosystem

Little is known about the effects of the high dose and types of manganese supplements on rumen environment at manganese intake level close above the limit of 150 mg/kg of dry feed matter. The effects of high dose of two manganese supplements (organic and inorganic) on rumen microbial ecosystem after four months of treatment of 18 lambs divided into three treatment groups were studied. We examined the enzyme activities (α-amylase, xylanase, and carboxymethyl cellulase), total and differential microscopic counts of rumen ciliates, total microscopic counts of bacteria, and fingerprinting pattern of the eubacterial and ciliates population analyzed by PCR-DGGE. Lambs were fed a basal diet with a basal Mn content (34.3 mg/kg dry matter; control) and supplemented either with inorganic manganous sulfate or organic Mn-chelate hydrate (daily 182.7, 184 mg/kg dry matter of feed, respectively). Basal diet, offered twice daily, consisted of ground barley and hay (268 and 732 g/kg dry matter per animal and day). The rumens of the lambs harbored ciliates of the genera of Entodinium, Epidinium, Diplodinium, Eudiplodinium, Dasytricha, and Isotricha. No significant differences between treatment groups were observed in the total ciliate number, the number of ciliates at the genus level, as well as the total number of bacteria. Organic Mn did decrease the species richness and diversity of the eubacterial population examined by PCR-DGGE. No effects of type of Mn supplement on the enzyme activities were observed. In comparison to the control, α-amylase specific activities were decreased and carboxymethyl-cellulase specific activities were increased by the Mn supplements. Xylanase activities were not influenced. In conclusion, our results suggested that the intake of tested inorganic and organic manganese supplements in excess may affect the specific groups of eubacteria. More studies on intake of Mn supplements at a level close to the limit can reveal if the changes in microbial population impact remarkably the other rumen enzymatic activities.

Quantification of organic acids in ruminal in vitro batch culture fermentation supplemented with fumarate using a herb mix as a substrate

Abstract: Two 24 h in vitro batch culture experiments were conducted to investigate the effects of fumarate addition (10 mmol L-1) on the ruminal fermentation parameters of selected medicinal herbs, and the effects of different doses of fumarate (0, 10, or 30 mmol L-1) on ruminal metabolism of organic acids when a high-concentrate diet (meadow hay and barley grain, 400/600, w/w) was supplemented with a mix of medicinal herbs (Artemisia absinthium L., Melissa officinalis L., Malva sylvestris L., Matricaria chamomilla L., Plantago lanceolata L., Foeniculum vulgare Mill., and Althaea officinalis L.). Depending on the concentration, fumarate treatment decreased methane production (by 10-11%) and increased propionate proportions (by 5-13%) with high-concentrate diets. The organic acid (fumaric, succinic, malic, and lactic acid) concentrations in the batch culture were measured at intervals of 0, 4, 6, 12, and 24 h. The time and organic acid concentrations with 10 mmol L-1 fumarate were well correlated (R 2 = 0.846). The amount of succinate was accumulated and metabolized more slowly than that of fumarate (>24 h). The addition of fumarate and a herb mix could positively influence in vitro ruminal fermentation parameters of high-concentrate diets by increasing the levels of propionate and succinate as well as the pH, and by decreasing of methane emissions.

Nutritional status of corn silage after probiotic conservation

The effects of two probiotic inoculants Enterococcus faecium 2/3s (EF2/3s) and E. faecium 26/42 (EF26/42) on nutritional patterns and fatty acid concentration in corn silages were examined. Both inoculants were isolated and characterized at Institute of Animal Physiology Slovak Academy of Sciences. The whole crop corn (341 g of dry matter (DM) kg−1) was conserved at 21°C for 111 days during the three treatments: (1) corn without inoculant (CS, control), (2) corn inoculated by the strain EF2/3s (CS + EF2/3s) and (3) corn inoculated by the strain EF26/42 (CS + EF26/42). Counts of the inoculated strains were enumerated (5.58 and 4.92 log10 cfu g−1 for EF26/42 and EF2/3s, respectively) immediately after their inoculation. At the end of conservation, EF26/42 achieved 1.60 ± 0.26 log10 cfu g−1 and EF2/3s less than 1.0 log10 cfu g−1. Compared to CS, the lactate values of inoculated CS were greater (P < 0.001). It can be concluded that both bacterial inoculants effectively enhanced in vitro DM degradability and lactic acid concentration in corn silages, but the effect on fatty acids concentration was inconsistent.