Supplemental protein degradation, bacterial protein synthesis and nitrogen retention in sheep eating sodium hydroxide-treated straw

1986 ◽  
Vol 55 (3) ◽  
pp. 557-569 ◽  
Author(s):  
K. Amaning-Kwarteng ◽  
R. C. Kellaway ◽  
A. C. Kirby

1. Alkali (sodium hydroxide)-treated wheat straw was given to six rumen- and abomasal-cannulated sheep to study the rumen degradation of cotton-seed meal (CSM) and barley (B), and the effects of these supplements on nitrogen retention and efficiency of bacterial protein synthesis were measured.2. N degradation, using porous synthetic (nylon) bags incubated within the rumen (P), and in vivo measurement determined from the abomasal flow of N (V), distinguished quantitatively between the two supplements. Estimates of P, corrected for fractional outflow rates/h (FOR), underestimated estimates of V when FOR of undegraded protein from the rumen (k) of 0.05 and 0.08 were used. Estimates of V for CSM and B were 70.9 and 80.8% respectively.3. Intakes of alkali-treated straw were not affected by the supplements. Intakes of digestible organic matter (DOM) for the diets comprising alkali-treated straw alone (W), straw plus CSM (WC) and straw plus barley (WB) were 477, 575 and 590 g/d respectively (P < 0.05) and organic matter (OM) apparently digested in the rumen (OMADR) was 339, 399 and 435 g/d respectively (P < 0.05).4. On W, WC and WB respectively, flows at the abomasum were 11.0, 14.0 and 13.3 g/d for bacterial N (P < 0.05) and 0,2.8 and 0.5 g/d for dietary supplemental N; g bacterial N/kg OMADR were 32.4, 35.6 and 30.9 (P > 0.05) and N balances were 2.37, 4.27 and 3.29 g/d (P < 0.05) on the respective treatments. It was suggested that supplements increased total OM intake as a result of increased OM digested in the rumen rather than OM flow from the rumen.

1975 ◽  
Vol 84 (3) ◽  
pp. 453-458 ◽  
Author(s):  
M. J. Ulyatt ◽  
J. C. Macrae ◽  
R. T. J. Clarke ◽  
P. D. Pearce

SUMMARYThe proportions of bacterial and dietary protein entering the duodenum of sheep fed fresh herbage were assessed using 2,6-diaminopimelic acid as a marker. The herbages fed wereLolium perenneL., ‘Grasslands Ruanui’ perennial ryegrass;L. (perenne × multiflorum), ‘Grasslands Manawa’ short-rotation ryegrass;Trifolium repensL., ‘Grasslands 4700’ white clover.The dietary protein degraded in the stomach was approximately 70% for all herbages. The bacterial contribution to protein entering the duodenum was 43·1, 57·1 and 52·9% for Ruanui, Manawa and white clover respectively. Protein entering the duodenum contained only a small amount of protozoal protein.Bacterial protein synthesis in the stomach was different for all three herbages, averaging 16·2, 30·7 and 19·8 g/100 g organic matter apparently digested for Ruanui, Manawa and white clover respectively. It is suggested that the micro-organisms digesting Manawa synthesized protein more efficiently.


2002 ◽  
Vol 15 (1) ◽  
pp. 95-110 ◽  
Author(s):  
Roland Nau ◽  
Helmut Eiffert

SUMMARY Several bacterial components (endotoxin, teichoic and lipoteichoic acids, peptidoglycan, DNA, and others) can induce or enhance inflammation and may be directly toxic for eukaryotic cells. Bactericidal antibiotics which inhibit bacterial protein synthesis release smaller quantities of proinflammatory/toxic bacterial compounds than Β-lactams and other cell wall-active drugs. Among the Β-lactams, compounds binding to penicillin-binding protein 2 (PBP-2) release smaller amounts of bacterial substances than antibacterials inhibiting PBP-3. Generally, high antibiotic concentrations (more than 10 times the MIC) induce the release of fewer bacterial proinflammatory/toxic compounds than concentrations close to the MIC. In several in vitro and in vivo systems, bacteria treated with protein synthesis inhibitors or Β-lactams inhibiting PBP-2 induce less inflammation than bacteria treated with PBP-3-active Β-lactams. In mouse models of Escherichia coli peritonitis sepsis and of Streptococcus pneumoniae meningitis, lower release of proinflammatory bacterial compounds was associated with reduced mortality. In conclusion, sufficient evidence for the validity of the concept of modulating the release of proinflammatory bacterial compounds by antibacterials has been accumulated in vitro and in animal experiments to justify clinical trials in sepsis and meningitis. A properly conducted study addressing the potential benefit of bacterial protein synthesis inhibitors versus Β-lactam antibiotics will require both strict selection and inclusion of a large number of patients. The benefit of this approach should be greatest in patients with a high bacterial load.


1990 ◽  
Vol 114 (1) ◽  
pp. 49-54 ◽  
Author(s):  
G. J. Cruickshank ◽  
D. P. Poppi ◽  
A. R. Sykes ◽  
A. S. Familton

SUMMARYThe voluntary food intake, in vivo digestibility and site of nutrient digestion was measured in 12 Polled Dorset ram lambs, from 6 to 24 weeks of age, offered clover hay. Lambs were weaned at 6 weeks of age. Six were fitted with a permanent T-shaped cannula in the abomasum and a temporary rumen catheter during the periods of digesta flow measurement.Surgical modification of lambs did not influence intake (g/kg live weight (W) per day), in vivo digestibility or marker retention time in the rumen. However, intact lambs grew significantly faster than cannulated lambs (139 v. 109g/day, P < 0·05) apparently because of an overall higher cumulative intake over the whole experimental period rather than any change in efficiency of use of nutrients or maintenance requirement.Relative to live weight, intake increased rapidly until c. 10 weeks of age and remained relatively constant at c. 37 g DM/kg W per day for the remainder of the experiment. Age had no effect on in vivo digestibility of organic matter (OM) or neutral detergent fibre (NDF) (average 0·69).The proportion of digestible organic matter apparently digested in the rumen (DOMADR) decreased from 0·63 to 0·47 between 8 and 24 weeks of age whilst intake between these measurement periods increased. Nonammonia N (NAN) flow past the abomasum was similar at all ages in relation to digestible organic matter intake (55·1 g NAN/kg DOMI) but was higher at 16 and 24 weeks of age than at 8 and 12 weeks of age, respectively, in relation to organic matter apparently digested in the rumen (OMADR) (116 and 85 g NAN/kg OMADR, respectively, P < 0·05).Fractional outflow rate of digesta markers from the rumen, when estimated from abomasal digesta, was significantly higher than when estimated from faeces (103Ru-p 0·121 v. 0·09; 51Cr-EDTA 0·169 v. 0·111/h; P > 0·05).It was concluded that cannulation did not affect intake and digestion characteristics in these young lambs. The changes in the site of nutrient digestion as the animals aged may have been due to agerelated changes in digestive function but appeared to be associated with the increase in intake that occurred between measurement periods of the cannulated lambs.


1976 ◽  
Vol 27 (1) ◽  
pp. 139 ◽  
Author(s):  
JG Mulholland ◽  
JB Coombe ◽  
WR McManus

Individually penned Border Leicester x Merino wethers, aged 11 months, were fed ad lib. for 16 weeks on a basal ration of ground, pelleted oat straw, urea and minerals, supplemented with 0, 5, 10, 15, 20, 30 or 40% starch. The diets contained equal percentages of nitrogen and minerals. Dry matter intake reached a maximum of 2000 g/day with 30% starch; above this starch level, digestive disturbances were observed. Organic matter digestibility was increased by the addition of starch, but cellulose digestibility was depressed by as much as 18 units with the addition of 30% starch. Up to 10% the starch level had little effect on cellulose digestibility. Liveweight change was significantly correlated with digestible organic matter intake, mean daily weight gains varying from 22 g with no starch to 104 g with 30% starch. However, a large percentage of the liveweight gain was as total body water, and body energy storage increased appreciably only when the diet contained at least 20% starch. The inclusion of 5% starch slightly depressed both intake and liveweight gain. Daily clean wool production was significantly increased at starch levels higher than 20% and ranged from 5.3 to 7.5 g/day with 0 and 40% starch respectively. Increasing levels of starch had little effect on apparent nitrogen digestibility, but resulted in a substantial increase in nitrogen retention through a reduction in urinary nitrogen excretion. Serum urea levels fell from a mean of 42 mg/100 ml during the first week to 31 mg/100 ml during subsequent periods, with no significant differences between diets. With the general exception of potassium, mineral balances were positive or close to zero throughout the experiment.


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