Source of Nitrogen for Rumen Microbes

Huque, Quazi Md. Emdadul; Thomsen, K.Vestergaard

doi:10.1080/00015128409436178

Cited by 13 publications

(4 citation statements)

References 19 publications

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“…Supplementation with U or SM stimulated TSDOC fermentation, as shown by the increase of daily VFA production and efficiency (by 1.6 and 2.8 and 1.2 and 2.0 times, respectively). The results obtained with TSDOC agreed with those of other authors, who found a higher stimulating effect on the fermentation when supplementing with NAN, in comparison with ammonia N [9,16,26,31]. The increased acetate production with PEG treatment would indicate an increased fermentation of TSDOC carbohydrates, in agreement with other observations [6,37].…”

Section: Discussionsupporting

confidence: 83%

Effect of polyethylene glycol, urea and sunflower meal supply on two-stage olive cake fermentation

et al. 2004

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-A continuous culture system, inoculated with rumen liquor from goats or sheep, was used to study the ruminal fermentation characteristics of the two-stage dried olive cake (TSDOC). The effects of adding polyethylene glycol (PEG; 0, 2 or 20 g per 100 g TSDOC) and/or supplementing with urea (U) or sunflower meal (SM) (1.5 g N per 100 g OM) were also studied. TSDOC fermentation promoted low volatile fatty acid (VFA) production (20.5 mmol per day), predominantly acetic acid, and low efficiency of VFA production (1.88 mol per kg digestible carbohydrates, DCHO). Both values increased (P < 0.001) with PEG and N addition, while no important differences ascribed to the origin of rumen inoculum were observed. Total and amino acid nitrogen output was low and increased (P < 0.001) with N addition without being affected by PEG treatment. Bacterial nitrogen production was calculated from the difference between non ammonia (NAN) and acid-detergent-insoluble nitrogen (ADIN) outputs. No important differences, deriving from the inoculum origin, were observed for bacterial N production rate and efficiency (g N per kg DCHO). Increased (P < 0.001) VFA, DCHO and bacterial N production and efficiency of VFA production were observed with N addition. The response to protein (i.e. sunflower meal) supply was more pronounced than to urea. Treatment of TSDOC with PEG increased VFA production (P < 0.001) (from 21.8 to 27.8 mmol per day) and efficiency of microbial N synthesis (P < 0.01) (from 17.7 to 27.1 g bacterial N per kg DCHO) but it decreased (P < 0.001) the DCHO production. a diminué la production des acides gras volatils (20,5 mmol par jour), principalement l'acide acétique, ainsi que l'efficience de leur production (1,88 mol par kg glucides digestibles, DCHO). Ces deux valeurs ont augmenté (P < 0,001) avec l'addition du PEG et l'apport azoté ; en revanche, l'origine du jus de rumen n'a eu que très peu d'effet. Les productions de matières azotées totales et d'acides aminés ont été faibles, mais elles ont augmenté (P < 0,001) avec l'addition d'azote, tout en n'étant pas affectées par le traitement avec le PEG. La quantité de matières azotées d'origine bactérienne a été calculée à partir de la différence entre la production d'azote non ammoniacal et la production d'azote insoluble dans le détergent acide (ADIN). La vitesse de production et l'efficacité de synthèse (g N par kg DCHO) d'azote microbien n'ont pas été affectées par l'origine du jus de rumen, alors que la supplémentation azotée a augmenté (P < 0,001) les quantités d'acides gras volatils, des glucides fermentés, d'azote microbien, ainsi que le rendement de production des acides gras volatils. La réponse obtenue avec le tourteau de tournesol a été plus prononcée que celle obtenue avec l'urée. Le traitement des grignons d'olive avec le PEG a augmenté (P < 0,001) la quantité des acides gras volatils (de 21,8 à 27,8 mmol par jour) et la production d'azote microbien (P < 0,01) (de 17,7 à 27,1 g d'azote microbien par kg DCHO), mais il a diminué (P < 0,001) la quantité de ...

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Section: Discussionsupporting

confidence: 83%

Effect of polyethylene glycol, urea and sunflower meal supply on two-stage olive cake fermentation

et al. 2004

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“…Protozoa have been reported to increase the turnover of bacterial protein in rumen fluid 13-fold (Wallace and McPherson 1987), with much of the catabolized protein being released as peptides (Denholm and Ling 1985). Huque and Thomsen (1984) and Thomsen (1985) have demonstrated that low polypeptide availability may limit the rate of cellulolysis by rumen microbes in-vitro. The higher rate of fermentation in the rumen of faunated sheep may therefore result from a greater availability of polypeptides for use by cellulolytic bacteria in the rumen, as well as from the action of protozoal cellulases in these animals.…”

Section: Rumen Fermentationmentioning

confidence: 99%

The effects of protozoa and of supplementation with nitrogen and sulfur on digestion and microbial metabolism in the rumen of sheep

Hegarty¹,

Nolan²,

Leng³

1994

Aust. J. Agric. Res.

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Two experiments were undertaken to study the effects of protozoa on sulfur and nitrogen availability and on fermentation and the composition of bacteria in the rumen of sheep. In Experiment 1, 12 faunated and 12 fauna-free sheep were offered a basal diet of chopped wheaten straw with or without sulfur (S) and urea-nitrogen (N) supplements. Sulfur supplementation increased the rate of straw digestion and the concentration of volatile fatty acids (VFA) in the rumen while reducing methane production. The presence of protozoa did not significantly affected this response, although it increased rumen H2S concentration. In contrast, the response of rumen fermentation to a urea supplement was affected by the presence of protozoa. Unsupplemented faunated sheep had a faster rate of in-sacco straw digestion in the rumen than did fauna free sheep (44 v. 36%DM/day). Supplementary urea increased the rate of in-sacco digestion of the basal ration in fauna free sheep (36 to 42%DM/day) but not in the faunated sheep (44 to 46%DM/day), suggesting that N availability was greater in the rumen of faunated sheep. Ammonia and total VFA concentrations in the rumen were not affected by protozoa, but the molar proportions of butyrate and isoacids in rumen VFA were greater in faunated sheep. Bacteria from the rumen fluid of faunated sheep contained a higher proportion of lipid and a lower proportion of N in their cell DM.In a second experiment, the chemical composition of rumen bacteria of faunated and fauna free sheep was further investigated. In both groups, bacteria associated with the particle-phase of digesta contained a higher proportion of lipid and a lower proportion of N than did fluid-phase bacteria. Fluid-phase bacteria from faunated sheep tended to have more lipid and less N in their DM than did those from fauna-free sheep.It was concluded that the presence of protozoa enables sustained fermentation of diets low in rumen available nitrogen and also increases the lipid content of rumen fluid-phase bacteria.

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“…These become activated only gradually after feeding, because they must first attach themselves to plant material (Mertens, 1977), and because the pH has not yet reached an optimum level for this activity. According to Huque & Vestergaard Thomsen (1984) cellulolytic microbes prefer certain polypeptides, as a nitrogen source. The availability of these polypeptides about three hours after the intake of concentrate protein is more likely on a feed with slowly degradable protein.…”

Section: Ammoniamentioning

confidence: 99%

The influence of slowly and rapidly degradable concentrate protein on a number of rumen parameters in dairy cattle.

Veen¹

1986

NJAS

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In 5 trials with Dutch Black Pied or Dutch Black Pied X Holstein-Friesian cows the effects of feeding concentrates with rapidly and slowly degradable protein on rumen values were investigated. Samples of rumen fluid were taken before and 45, 90, 135 and 180 min after the morning concentrate feed. Rumen pH was not affected by protein degradability. Rumen ammonia content was higher when easily degradable protein was given than when slowly degradable protein was given; peak concentration varied from 10 to 12.5 and from 4 to 8 mmol/litre, respectively. Maximum concentration of lactate was not influenced by protein degradability. Rumen content of volatile fatty acids increased more rapidly when the slowly degradable protein rather than when the rapidly degradable protein was given. At all sampling times the molar acetate:propionate ratio was higher after feeding on slowly degradable protein than after rapidly degradable protein. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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Source of Nitrogen for Rumen Microbes

Cited by 13 publications

References 19 publications

Effect of polyethylene glycol, urea and sunflower meal supply on two-stage olive cake fermentation

Effect of polyethylene glycol, urea and sunflower meal supply on two-stage olive cake fermentation

The effects of protozoa and of supplementation with nitrogen and sulfur on digestion and microbial metabolism in the rumen of sheep

The influence of slowly and rapidly degradable concentrate protein on a number of rumen parameters in dairy cattle.

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