• Asian-Australasian Journal of Animal Sciences
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• 제8권3호
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• pp.249-254
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• 1995

The effects of bentonite (B) on rumen protozoal population and rumen fluid characteristics of sheep fed palm kernel cake (PKC) were studied for a period of 21 days. Two groups, each comprising two sheep were fed either PKC or PKC + B ad libitum A third group was left at pasture. Rumen fluid was sampled through a rumen cannula three times daily from all animals. Palm kernel cake contained 16% crude protein, 1 % crude fat and high amounts of copper, zinc, iron and manganese. Protozoal population in the rumen fluid decreased significantly (p < 0.05) after the onset of feeding PKC or PKC + B. However, sheep given bentonite supplementation at 2% of the dietary dry matter, maintained higher protozoal densities ($15{\times}10^4/ml$) when compared to animals fed only PKC ($8{\times}10^4/ml$). With both diets, the protozoa were mainly of the small entodinia species. Animals at pasture had higher protozoal population ($47{\times}10^4/ml$) with varying species of entodiniomorphids and holotrichs. Rumen fluid pH and ammonia concentration was significantly (p < 0.05) higher in animals at pasture compared to animals fed PKC or PKC + B. Volatile fatty acid concentration was significantly (p < 0.05) lower in animals fed PKC when compared to animals at pasture. There was a shift in fermentation pattern in animals fed PKC or PKC + B towards a lower acetate; and higher propionate, isovalerate and valerate. Studies in vitro also showed the positive effect of bentonite on protozoal numbers.

• Animal Bioscience
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• 제37권2_spc호
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• pp.337-345
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• 2024

Ruminants possess a specialized four-compartment forestomach, consisting of the reticulum, rumen, omasum, and abomasum. The rumen, the primary fermentative chamber, harbours a dynamic ecosystem comprising bacteria, protozoa, fungi, archaea, and bacteriophages. These microorganisms engage in diverse ecological interactions within the rumen microbiome, primarily benefiting the host animal by deriving energy from plant material breakdown. These interactions encompass symbiosis, such as mutualism and commensalism, as well as parasitism, predation, and competition. These ecological interactions are dependent on many factors, including the production of diverse molecules, such as those involved in quorum sensing (QS). QS is a density-dependent signalling mechanism involving the release of autoinducer (AIs) compounds, when cell density increases AIs bind to receptors causing the altered expression of certain genes. These AIs are classified as mainly being N-acyl-homoserine lactones (AHL; commonly used by Gram-negative bacteria) or autoinducer-2 based systems (AI-2; used by Gram-positive and Gram-negative bacteria); although other less common AI systems exist. Most of our understanding of QS at a gene-level comes from pure culture in vitro studies using bacterial pathogens, with much being unknown on a commensal bacterial and ecosystem level, especially in the context of the rumen microbiome. A small number of studies have explored QS in the rumen using 'omic' technologies, revealing a prevalence of AI-2 QS systems among rumen bacteria. Nevertheless, the implications of these signalling systems on gene regulation, rumen ecology, and ruminant characteristics are largely uncharted territory. Metatranscriptome data tracking the colonization of perennial ryegrass by rumen microbes suggest that these chemicals may influence transitions in bacterial diversity during colonization. The likelihood of undiscovered chemicals within the rumen microbial arsenal is high, with the identified chemicals representing only the tip of the iceberg. A comprehensive grasp of rumen microbial chemical signalling is crucial for addressing the challenges of food security and climate targets.

• 한국초지조사료학회지
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• 제37권1호
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• pp.1-9
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• 2017

This research was conducted to investigate the effects of feeding high and low forage diets with different forage sources on rumen fermentation characteristics and blood parameters of Holstein cows during the dry period. Eight Holstein cows were completely randomized assigned to two groups and repeated measurement was utilized in the analysis. Cows in two treatments were fed with diets with high (F:C = 70:30, 70F; forage source: mixed-sowing whole crop barley and Italian ryegrass silage, BIRG) and low (F:C = 55:45, 55F; forage source: tall fescue hay, TF) forage level. Rumen fluid pH was higher in 70F group. Levels of acetic acid, propionic acid, and butyric acid showed a similar pattern: from the lowest value at 07:30 h to the highest at 10:30 h and then decreased in both groups. The ratio of acetic acid to propionic acid was significantly higher (p < 0.05) in 55F group at 09:30 and 10:30 h. Rumen fluid $NH_3-N$ concentrations were significantly higher (p < 0.05) in 70F group at 09:30 and 10:30 h. Blood urea nitrogen was significantly higher (p < 0.05) in 70F group. It was concluded that BIRG based diet with a high forage level had no adverse effects on rumen fermentation, some blood chemical parameters, and immune system in dry Holstein cows and could be used as a forage source instead of imported TF.

• Asian-Australasian Journal of Animal Sciences
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• 제8권1호
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• pp.37-41
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• 1995

Streptococci and enterococci, isolates from the rumen content of mouflons and European bisons were isolated. The total counts of these species reached the values(log 10 ${\pm}$ S.E.M.) $7.3{\pm}0.21$; $6.1{\pm}0.06$ bacteria per one ml of the rumen content in streptococci and $3.6{\pm}0.20$; $3.17{\pm}0.18$ bacteria per one ml of the rumen content in enterococci, Strains isolated were allotted to te species Streptococcus bovis(AM1, AM2, AM3, AM4), Enterococcus faecium(EH1, EFG2, EC3) and Enterococcus faecalis (EFA1, EFD2). Bactera presented belong to the strains with low urease and ${\alpha}$-amylase activities. The majority of isolates were polyresistant. Each strain produced bacteriocin - like substance with effect against at least of one of relatives species as indicators used. The most of inhibition zones were hazy with the width 2-6 mm in diameter.

• Asian-Australasian Journal of Animal Sciences
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• 제9권1호
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• pp.51-56
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• 1996

In this Experiment three wether male Matou goats (♂), all fitted with permanent rumen fistulae, were used to study the rumen degradabilities (incubation time 48h) of dry matter (DM), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent ligin (ADL), cellulose (CEL) and hemicellulose (HC) and their contents of wheat and rice straws were determined for the different morphological fractions and segments. The results showed that the variation of different fractions for wheat and rice straw is the true resources of their nutritive value variation and the cell wall contents of wheat and rice straw are also obviously different. The rumen degradabilities of different straw fibre are significantly different (p<0.01), mean while the effect of straw variety is also significant (p<0.05). The aim was to set up a foundation for studying the rumen degradation of the roughage resources.

• Asian-Australasian Journal of Animal Sciences
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• 제12권8호
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• pp.1205-1214
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• 1999

Whole lupinus albus seeds were pressure toasted at temperatures of 100, 118 and $136^{\circ}C$ for 3, 7, 15 and 30 min to study rumen degradation and post-rumen digestion and to determine optimal heating conditions for the Dutch dairy feed industry. In sacco nylon bag and mobile bag techniques were employed for rumen and intestine incubations to determine ruminal degradation characteristics and intestinal digestion of crude protein (CP) in 4 lactation rumen cannulated and 4 lactating intestinal cannulated Dutch dairy cows fed 47% hay and 53% concentrate according to Dutch dairy requirements. Measured rumen degradation characteristics were soluble fraction (S), undegradable fraction (U), potentially degradable fraction (D), lag time (T0) and rate of degradation (Kd) of insoluble but degradable fraction. Percentage bypass feed protein (BCP), ruminal microbial protein synthesized based on available nitrogen (N_MP) and that based on available energy (E_MP), true protein supplied to the small intestine (TPSI), truly absorbed BCP (ABCP), absorbed microbial protein (AVP) in the small intestine, endogenous protein losses in the digestion (ENDP), true digested protein in the small intestine (TAP or DVE in Dutch) and degraded protein balance (PDB or OEB in Dutch) were totally evaluated using the new Dutch DVE/OEB System. Pressure toasting decreased (p<0.001) rumen degradability of CP. It reduced S (p<0.05) and Kd (p=0.06), increased D (p<0.05) and U (p<0.01) but did not alter T0 (p>0.05), thus resulting in dramatically increased BCP (p<0.001) with increasing time and temperature from 73.7 (raw) up to 182.5 g/kg DM ($136^{\circ}C/15min$). Although rumen microbial protein synthesized based on available energy (E_MP) was reduced, true protein (microbial and bypass feed protein) supplied to the small intestine (TPSI) was increased (p<0.001) from 153.1 (raw) to 247.6 g/kg DM ($136^{\circ}C/15min$). Due to digestibility of BCP in the intestine not changing (p>0.05) average 87.8%, the absorbed BCP increased (p<0.001) from 62.3 (raw) to 153.7 g/kg DM ($136^{\circ}C/15min$). Therefore DVE value of true digested protein in the small intestine was significantly increased (p<0.001) from 118.9 (raw) to 197.0 g/kg DM ($136^{\circ}C/15min$) and OEB value of degraded protein balance was significantly reduced (p<0.001) from 147.2 (raw) to 63.1 g/kg DM ($136^{\circ}C/15min$). It was concluded that pressure toasting was effective in shifting degradation of CP of lupinus albus from the rumen to small intestine without changing intestinal digestion. Further studies are required on the degradation and digestion of individual amino acids and on the damaging effects of processing on amino acids, especially the first limiting amino acids.

• Asian-Australasian Journal of Animal Sciences
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• 제15권7호
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• pp.974-981
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• 2002

Faba beans (vicia faba) (FB) and lupin seeds (Lupinus Albus) (LS) were dry roasted at three temperatures (110, 130, $150^{\circ}C$) for 15, 30 or 45 min to determine the effects of dry roasting on rumen degradation of crude protein and starch free organic matter ($^{PSF}OM$). Rumen degradation characteristics of $^{PSF}OM$ were determined by the nylon bag incubation technique in dairy cows fed 60% hay and 40% concentrate. Measured characteristics of $^{PSF}OM$ were undegradable fraction (U), degradable fraction (D), soluble fraction (S), lag time (T0), and the rate of degradation (Kd). Based on the measured characteristics, rumen availability ($RA^{PSF}OM$) and bypass $^{PSF}OM$ ($B^{PSF}OM$) were calculated. Dry roasting did not have a greater impact on rumen degradation characteristics of $^{PSF}OM$ (p>0.05). S varied from 32.1 (raw) to 30.0, 27.8, 30.8% (LS) and 15.4 (raw) to 14.4, 20.8, 20.9% (FB); D varied from 65.4 (raw) to 66.3, 66.9, 55.9% (LS) and 54.9 (raw) to 55.0, 51.0, 64.7% (FB); U varied from 2.6 (raw) to 7.3, 7.0, 7.7% (LS) and 29.7 (raw) to 30.6, 28.2, 14.4% (FB); Kd varied from 6.0 (raw) to 7.3, 7.0, 7.7% (LS) and 22.4 (raw) to 24.4, 21.1, 7.9% (FB); $B^{PSF}OM$ varied from 35.5 (raw) to 33.8, 36.6, 38.2% (LS) and 41.3 (raw) to 41.5, 39.7, 47.6% (FB) at 110, 130 and $150^{\circ}C$, respectively. Therefore dry roasting did not significantly affect $RA^{PSF}OM$, which were 353.7, 367.9, 349.6, 336.9 (g/kg DM) (LS) and 12.82, 127.0, 133.7, 117.1 (g/kg DM) (FB) at 110, 130 and $150^{\circ}C$, respectively. These results alone with our previously published reports indicate dry roasting had the differently affected pattern of rumen degradation characteristics of various components in LS and FB. It strongly increased bypass crude protein (BCP) and moderately increased starch (BST) with increasing temperature and time but least affected $^{PSF}OM$. Such desirable degradation patterns in dry roasted LS and FB might be beneficial to the high yielding cows which could use more dry roasted $^{PSF}OM$ as an energy source for microbial protein synthesized in the rumen and absorb more amino acids and glucose in the small intestine.

• Asian-Australasian Journal of Animal Sciences
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• 제26권10호
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• pp.1466-1473
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• 2013

This experiment was conducted to study the variation laws and correlations of shearing force and feed characteristics including morphological characteristic, chemical composition and in situ degradability of wheat straw. Feasibility of evaluating the nutritional value of wheat straws with shearing force values was analyzed in this study. Six hundred wheat straw plants (Jimai 22) were randomly selected and placed in a cool and ventilated place. Samples were collected in the 1st, 15th, 30th, 45th, 60th d after harvest to measure shearing force, morphological characteristic, nutritional composition. Rumen degradation of dry matter (DM), neutral detergent fiber (NDF) and acid detergent fiber (ADF) of wheat straws were determined by the nylon bags method. The results demonstrated that linear and quadratic effects of storage time on all the tested morphological characteristics were significantly correlative (p<0.01). As storage time goes on, all the tested nutrients and their rumen degradations of wheat straw was linearly (p<0.01) and quadratic (p<0.01) correlative except ADF content and rumen degradation of ADF. Significant correlations were determined in linear effect of shearing force on morphological characteristics (p<0.01), and linear density and diameter were a more sensitive predictor than stem thickness for shearing force. There were strong correlations between storage time and all the measured physical characteristics (shearing force, morphological characteristics and shearing force standardized by morphological characteristics) (p<0.01). Nutrition compositions were linearly correlative with shearing force and standardized shearing force (p<0.01). The linear correlation between rumen degradation of DM and NDF and shearing force and standardized shearing force were evident (p<0.01). In conclusion, shearing force, nutrition compositions and their rumen degradation of wheat straw were still dynamic with storage time after harvest. Correlation could be found between shearing force and nutritional characteristics of wheat straw. Nutrient content, morphological index and rumen degradation of DM and NDF could be predicted by changes in shearing force. Shearing force should be applied according to a standardized storage time when it is used to forecast the feed value of wheat straws.

• Asian-Australasian Journal of Animal Sciences
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• 제16권10호
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• pp.1482-1486
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• 2003

In order to compare effects of feeding systems on rumen fermentation characteristics and nutrient digestion, steers were fed either total mixed ration (TMR) or separate concentrate-roughage ration (CR). Total tract digestibility of nutrients was higher in steers receiving TMR. Especially, DM, ADF and NDF in TMR were digested to a greater extent than those in CR. Rumen pH was not influenced by the feeding systems. Holstein steers on TMR had higher ruminal $NH_3$-N than those on CR. Feeding system did not alter VFA production but TMR feeding resulted in lower A/P ratio. TMR feeding tended to increase the number of bacteria and protozoa in the rumen fluid. Also steers fed TMR generally had higher fiber degrading enzyme activities, which might be the result of increased number of cellulolytic microbes in the rumen of animals on TMR. Our results indicate that TMR may provide more favorable condition for nutrient digestion both in the rumen and in the total tract of steers.

• Asian-Australasian Journal of Animal Sciences
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• 제16권11호
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• pp.1625-1633
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• 2003

This study was conducted to observe effects of dietary acidogenicity value (AV) on rumen fermentation characteristics and nutrients digestibility. The AV of feedstuffs was based on the dissolution of Ca from $CaCO_3$ powder added at the end of a 24 h in vitro fermentation. Three diets were formulated to be iso-energetic and iso-nitrogenous with different AV. Two experiments were involved in this study. In experiment 1, it appears that pH, $NH_3-N$ concentration and A:P ratio tended to decrease, but gas production, VFA production and DM disappearance tended to increase with increasing dietary AV. In experiment 2, the rumen pH tended to decrease in order of high AV>medium AV>low AV treatment, respectively. There were no significant effects of dietary AV on $NH_3-N$ concentration, enzyme activity and nutrient digestibility. In addition, total VFA and individual VFA concentrations tended to increase with increasing dietary AV without significance. In fact, we hypothesized that different dietary AV would affect rumen fermentation and nutrients digestibility because dietary AV was adjusted with fermentable carbohydrate sources. The present results indicate that differences in dietary AV between treatments were too small to affect rumen fermentation and its effects were minimal.