Measurement in sheep of the quantity and composition of rumen digesta and of the fractional outflow rates of digesta constituents

Faichney, GJ

doi:10.1071/ar9801129

Cited by 111 publications

(70 citation statements)

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“…However, higher values have been reported in other in vivo experiments. Craig et al (1987) reported a proportion of 70 -80 % of SAM in the rumen of cows fed a 65 % alfalfa haylage diet, with values up to 90 % in animals fed all-roughage diets (Faichney, 1980). The lower values in our batch culture system compared with some of those observed in vivo could be due to the different experimental conditions.…”

Section: Discussionmentioning

confidence: 45%

Influence of nitrogen source on the fermentation of fibre from barley straw and sugarbeet pulp by ruminal micro-organismsin vitro

et al. 2001

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Incubations were carried out with a batch culture system to study the effects of different N sources on the fermentation by ruminal micro-organisms from Merino sheep of two fibre substrates derived from feedstuffs that differed in their fermentation rate. The substrates were neutral-detergent fibre (NDF) from barley straw and sugarbeet pulp. N sources were ammonia (NH 4 Cl) and peptides (Trypticase). Three treatments were made by replacing ammonia-N with peptide-N at levels of 0 (AMMO), 33 (PEPLOW) and 66 % (PEPHIGH) of total N. There were no differences (P.0 : 05) between treatments in NDF degradation for both the barley straw and the sugarbeet pulp. Peptides increased (P,0 : 05) total volatile fatty acids daily production for both substrates, with greater values (P,0 : 001) for PEPHIGH than for PEPLOW for the sugarbeet pulp. The presence of peptides also increased (P,0 : 05) microbial N synthesis compared with AMMO, with PEPHIGH supporting more growth (P,0 : 001) than PEPLOW when the sugarbeet pulp NDF was fermented. The presence of peptides increased (P,0 : 01) the amount of solidsassociated micro-organisms (SAM)-N for both the barley straw and the sugarbeet pulp fibres, values in the PEPHIGH treatment being higher (P,0 : 001) than those in PEPLOW. The proportion of SAM-N in the total microbial N was not affected (P.0 : 05) by the presence of peptides compared with the AMMO treatment, but values were greater for the PEPHIGH compared with the PEPLOW N source, reaching statistical significance (P,0 : 05) only for the sugarbeet pulp. For liquid-associated micro-organisms, the AMMO treatment resulted in the greatest (P,0 : 05) proportion of N derived from ammonia for both substrates, with a further decrease (P,0 : 01) for the PEPHIGH treatment compared with the PEPLOW for the sugarbeet pulp, indicating preferential uptake of peptides when they were available. Microbial growth efficiency (g microbial N/kg NDF degraded) was not affected (P.0 : 05) by N source. These results indicate that N forms other than ammonia are needed for maximal growth of fibredigesting ruminal micro-organisms.

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Section: Discussionmentioning

confidence: 45%

Influence of nitrogen source on the fermentation of fibre from barley straw and sugarbeet pulp by ruminal micro-organismsin vitro

et al. 2001

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“…The quantity of bacteria adherent to ruminal digesta can be altered by the previously mentioned dietary alterations as well as the presence of feed additives in the diet [76,77]. The impact of changing a component of the diet on ruminal fermentation has been of interest to many researchers.…”

Section: Microbial Fermentation In the Rumenmentioning

confidence: 99%

Effects of ractopamine hydrochloride are not confined to mammalian tissue: Evidence for direct effects of ractopamine hydrochloride supplementation on fermentation by ruminal microorganisms1

Walker

Drouillard

2010

Journal of Animal Science

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Beta-adrenergic agonists, which are synthetic catecholamines, increase rate of gain, improve feed efficiency, and decrease carcass fat when fed to cattle before slaughter. However, little attention has been given to the potential effects of beta-adrenergic agonists on the rumen ecosystem. Natural catecholamines, such as norepinephrine, epinephrine, and dopamine, have been observed to stimulate bacterial growth. The objectives of this research were to determine if ractopamine hydrochloride (RAC) a synthetic catecholamine has direct effects on growth and fermentation products of ruminal bacteria, and to determine the effects of protein source on ruminal fermentation and proteolysis when cattle are fed RAC. The effects of varying concentrations of RAC on ruminal fermentation were evaluated in vitro. Ractopamine hydrochloride had a quadratic effect on in vitro gas production (P < 0.05). Total VFA production was not changed with RAC (P > 0.50). Different concentrations of RAC were evaluated in vitro with different nitrogen sources to determine effects of nitrogen degradability on response to RAC. There was an interaction between RAC and nitrogen substrate (P < 0.01), with more degradable forms of nitrogen eliciting greater changes in in vitro dry matter disappearance (IVDMD) with RAC supplementation. Significant main effects also were detected for RAC, substrate, and hour (P < 0.001). In vitro analysis of proteolysis revealed that RAC lowered ammonia and amino acid concentrations (P < 0.001). In vivo ruminal ammonia concentrations also were lower when RAC was fed in combination with dry-rolled corn, but not when fed in conjunction with steam-flaked corn (grain processing × RAC, P < 0.01). Addition of RAC, steam-flaked corn, and distiller's grains (DG) all resulted in lower ruminal ammonia concentrations (P < 0.01). Amino acid concentrations were decreased when RAC was added to diets with DG but were unchanged in diets without added DG (DG × RAC, P < 0.05). Results from these studies suggest that RAC affects fermentation by ruminal microflora. However, there were no differences in growth or fermentative end products of pure bacterial cultures with the addition of RAC (P > 0.10). Overall beta-adrenergic agonists alter ruminal fermentation, which could have important implications for diet formulation. EFFECTS OF RACTOPAMINE HYDROCHLORIDE ARE NOT CONFINED TO AbstractBeta-adrenergic agonists, which are synthetic catecholamines, increase rate of gain, improve feed efficiency, and decrease carcass fat, when fed to cattle before slaughter. However, little attention has been given to the potential effects of beta-adrenergic agonists on the rumen ecosystem. Natural catecholamines, such as norepinephrine, epinephrine, and dopamine, have been observed to stimulate bacterial growth. The objectives of this research were to determine if ractopamine hydrochloride (RAC) a synthetic catecholamine has direct effects on growth and fermentation products of ruminal bacteria, and to determine the effects of protein source on rumin...

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“…Although there is little information about the contribution of SAB and LAB to total bacterial flow, the relative proportion of SAB and LAB in the rumen can be affected by dietary factors. Indeed, Faichney (1980) reported that the proportion of SAB reached 90% in sheep fed forage only whereas it declined to 50% for steers fed equal proportions of forage and concentrate (Merry and McAllan, 1983). Hence, variation in relative proportions of SAB and LAB could largely influence estimates of rumen microbial synthesis when either SAB or LAB marker:N ratios are used for calculations.…”

Section: Introductionmentioning

confidence: 99%

Effect of variation in the proportion of solid- and liquid-associated rumen bacteria in duodenal contents on the estimation of duodenal bacterial nitrogen flow

Vlaeminck¹,

Fievez²,

Demeyer³

et al. 2007

J. Anim. Feed Sci.

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The aim of this research was to examine to what extent variation in the relative proportions of solid-(SAB) and liquid-associated rumen bacteria (LAB) in duodenal bacteria have an impact on the estimation of duodenal flow of bacterial N. For this, four dairy cows were fed diets varying in forage: concentrate ratio (80:20, 65:35, 50:50 and 35:65). SAB and LAB were separated from rumen contents four h after the morning feeding. Adenine, cytosine and odd and branched-chain fatty acids were determined both in SAB and LAB and used to estimate bacterial N flow. Bacterial N flows were also calculated using a SAB:LAB ratio in duodenal bacteria, as estimated from the odd and branched-chain fatty acid pattern. Compared with calculations based on the estimated SAB:LAB ratio, estimations based on SAB or LAB only as a bacterial reference on average over-and underestimated bacterial N flow by 37 and 55 g N/d, respectively (P<0.05) when cytosine or adenine were used as bacterial marker. In contrast, due to the small differences in the OBCFA:N ratio between SAB and LAB, these differences were less than 15 g/d when OBCFA were used as bacterial marker. The results suggest that, depending on the marker used, changes in the proportions of SAB and LAB can have a substantial impact on estimated duodenal flow of bacterial N.

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Measurement in sheep of the quantity and composition of rumen digesta and of the fractional outflow rates of digesta constituents

Cited by 111 publications

References 1 publication

Influence of nitrogen source on the fermentation of fibre from barley straw and sugarbeet pulp by ruminal micro-organismsin vitro

Influence of nitrogen source on the fermentation of fibre from barley straw and sugarbeet pulp by ruminal micro-organismsin vitro

Effects of ractopamine hydrochloride are not confined to mammalian tissue: Evidence for direct effects of ractopamine hydrochloride supplementation on fermentation by ruminal microorganisms1

Effect of variation in the proportion of solid- and liquid-associated rumen bacteria in duodenal contents on the estimation of duodenal bacterial nitrogen flow

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