Rumen bacterial protein synthesis and the proportion of dietary protein escaping degradation in the rumen of sheep

1980 ◽  
Vol 43 (3) ◽  
pp. 421-433 ◽  
Author(s):  
J. R. Mercer ◽  
Sarah A. Allen ◽  
E. L. Miller
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Production Rate ◽  
Diaminopimelic Acid ◽  
Energetic Efficiency ◽  
Food Protein ◽  
Bacterial Protein ◽  
Protein Nitrogen ◽  
The Mean ◽  
Bacterial Protein Synthesis

1. The effect of supplementing barley diets with urea (U), extracted, decorticated groundnut meal (GNM) or Peruvian fish meal (PFM) on rumen bacterial protein synthesis and the proportion of undegraded food protein passing to the duodenum of sheep has been examined.2. Three wethers were given isonitrogenous, isoenergetic diets containing (g/kg dry matter (DM)): U 20, GNM 106 or PFM 78, the crude protein (nitrogen × 6.25) contents being 139, 145 and 148 respectively. The sheep were fed hourly, the mean daily intake of DM being 0.634 kg.3. Rumen bacterial protein synthesis was determined using35S and diaminopimelic acid (DAPA) as bacterial markers and polyethylene glycol (PEG) and chromic oxide as markers of digesta flow. Rumen volatile fatty acid (VFA) production rate was determined by a continuous infusion of [I-14C]acetate. 4. and DAPA gave similar estimates of the proportion of bacterial N in the trichloroacetic acid- precipitable nitrogen of the rumen digesta, the mean value being 0.86. The VFA production rate did not vary significantly between diets, the mean being 5.8 mol/24 h. The flow of bacterial N from the rumen was calculated from the PEG and Cr2O3, estimates of flow and the35S and DAPA estimates of the proportion of bacterial N in the rumen. and DAPA gave similar values (mean 12.5 g/24 h) and Cr2O3, gave a slightly lower value (11.5 g/24 h) than PEG (13.5 g/24 h). Dietary effects, averaged over the four methods, were not significant; the values were 13.0, 13.4 and I 1–0 g/24 h for the U, GNM and PFM diets respectively.5. Duodenal samples were taken from two 12h continuous collections from re-entrant cannulas and the DM flow adjusted to total recovery of Cr2O3,. The mean recovery of Cr203at the duodenum was 0.798. The rates of flow of DM were 0.296,0.311 and 0.334 kg/24 h and of non-ammonia-N (NAN) 13.5, 15.2 and 15.4 g/24 h on the U, GNM and PFM diets respectively.6. The concentrationsof the essential amino acids in duodenal digestaweregenerally higher with the PFM diet than with either of the other two diets. The flow of most amino acids through the duodenum was generally higher on the PFM and GNM diets than on the U diet.7. The energetic efficiency of bacterial protein synthesis was calculated to be 2.1 g bacterial N/mol VFA or 28 g bacterial N/kg organic matter fermented in the rumen.8. From the estimates of bacterial N flow from the rumen and NAN flow through the duodenum it was calculated that 0.22 and 0.69 of the supplemental N from GNM and PFM respectively passed through the rumen undegraded.

scholarly journals Utilization of low-quality roughages; effects of supplementing with casein treated or untreated with formaldehyde on digesta flows, intake and growth rate of cattle eating wheat straw

1982 ◽  
Vol 47 (3) ◽  
pp. 553-563 ◽  
Author(s):  
N. Sriskandarajah ◽  
R. C. Kellaway ◽  
Jane Leibholz
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Wheat Straw ◽  
Live Weight ◽  
Bacterial Protein ◽  
Weight Changes ◽  
Period 2 ◽  
The Mean ◽  
C 30 ◽  
Bacterial Protein Synthesis

1. Expt 1. Forty 200 kg heifers were given wheat strawad lib. plus one of five pelleted supplements, each of which supplied 40 g/nitrogen as urea/d, Treatment A did not supply other sources of N, and other treatments supplied daily 40 g digestible N as casein and formaldehyde-treated casein (HCHO-casein) in the following proportions (w/w): 100:0 (B), 70:30 (C), 30:70 (D), 0:100 (E). After 5 weeks (period 1) all supplements were withdrawn from half (four) of the animals in each treatment group (NS) over a period of 8 weeks (period 2). At the end of period 2. N balances were measured in four animals on each of treatments E and NS.2. In period 1 the mean intake of straw by animals on treatments D and E was higher than the mean intake by animals on treatments A, B and C (3·32v. 2·83 k/d respectively,P< 0·01) and live-weight changes also differed significantly (+ 72 and – 126g/d respectively:P< 0·01). Intakes of straw in period 2 were 3·74 and 3·20 kg/d for animals with and without supplements respectively (P< 0·01) and live-weight changes were +110 and – 157 g/d on the respective treatments (P< 0·01). For animals receiving supplements in period 2, intakes of straw did not differ significantly between supplements; live-weight changes were −14 g/d on treatment A and +141 g/d on treatments B, C, D and E (P< 0·01).3. N balances on treatments E and NS were +11·4 and – 3·3 g/d respectively (P< 0·01), although digestibility of organic matter (OM) was similar on the two treatments.4. Expt 2. Four 185 kg steers with rumen and abomasal cannulas were given wheat strawad lib. plus one each of treatments A, B and E in a randomized block sequence. Dry matter (DM) intakes were 3·44, 3·89 and 4·05 kg/d on treatments A, B and E respectively (P< 0·05). N intakes were 29 and 37 g/d higher on treatments Band E respectively than on treatment A, but abomasal flows of N were only 4 and 14 g/d higher on the respective treatments. The latter value indicates that approximately 0·62 of HCHO-casein was degraded in the rumen. Efficiencies of bacterial protein synthesis were 31, 24 and 26 g bacterial N/kgOM apparently digested in the rumen (P> 0·05) on treatments A, B and E respectively.5. It was concluded that efficiency of bacterial protein synthesis in the rumen was not limited by the supply of peptides and amino acids, and that protein supplements do not consistently stimulate intake of low-quality roughages when requirements for rumen degradable N have been met. Higher flows of N to the intestines when HCHO-casein, and to a lesser extent casein, were given were associated with a shift from negative to positive live-weight changes. These live-weight changes were not significantly correlated with DM intakes from which it appears that effects of casein supplements on live weight may have been attributable to effects of absorbed amino acids on efficiency of tissue protein synthesis either directly or through gluconeo genesis.

scholarly journals THE ABNORMAL COURSE OF BACTERIAL PROTEIN SYNTHESIS IN THE PRESENCE OF PENICILLIN

1950 ◽  
Vol 91 (4) ◽  
pp. 351-364 ◽  
Author(s):  
Rollin D. Hotchkiss
Keyword(s):  
Amino Acids ◽  
Amino Nitrogen ◽  
Cellular Protein ◽  
Penicillin G ◽  
Bacterial Protein ◽  
Protein Nitrogen ◽  
Amino Acid Nitrogen ◽  
Extracellular Substances ◽  
Bacterial Protein Synthesis ◽  
Peptone Broth

Washed staphylococcal cells separated from peptone-broth cultures containing penicillin G did not differ markedly from cells not exposed to penicillin in their rate of oxygen, phosphate, glutamic acid, or amino nitrogen utilization. Washed normal staphyloccal cells, respiring in solutions containing glucose and various mixtures of amino acids, utilized the amino acids with an increase in the cellular protein nitrogen. Similar cells under the same conditions, but exposed to penicillin G, utilized oxygen, phosphate, and amino acids at essentially the same rates, but there was no increase in the protein nitrogen of the cells. Penicillin-treated washed cells, when utilizing amino acids, produced increased amounts of extracellular substances containing non-amino nitrogen in quantities approximately equivalent to the amino acid nitrogen utilized. The non-amino fraction could be tentatively identified as polypeptide, which was produced, instead of cellular protein, when penicillin was present.

Quantitative and qualitative influences of dietary urea on the composition of duodenal digesta in calves

1975 ◽  
Vol 84 (3) ◽  
pp. 469-474 ◽  
Author(s):  
J. Anna Nikolić ◽  
A. Pavličević ◽  
Tereza Zebrowska
Keyword(s):  
Amino Acids ◽  
Dry Matter ◽  
Duodenal Content ◽  
Diaminopimelic Acid ◽  
Bacterial Protein ◽  
Bull Calves ◽  
Before And After ◽  
Beet Pulp ◽  
The Difference ◽  
Bacterial Protein Synthesis

SUMMARYThe aim of the present investigation was to determine the effect of adding urea to a diet based on ground maize and dried sugar-beet pulp (2/1) on the composition of duodenal content and diet digestibility in calves.Two bull calves (140 kg) were provided with duodenal fistulae and pair fed the ration alone or with 1·2% urea in a cross-over design. Lucerne hay was also given. The difference in intake of nitrogen between the two diets was 18·4 g/day.The results obtained showed negligible differences between the diets in the amounts of dry matter, organic matter and energy disappearing both before and after the duodenum. Digestibility of nitrogen was greater with the urea-containing diet.Although some of the added urea (25%) was apparently lost from the forestomach, the duodenal digesta contained 13·7 g N/day more with the diet containing urea. Of this a minimum of 6·5 g was in the form of amino acid-N and only 0·4 g as ammonia-N. All the amino acids determined were present in increased amounts but lysine and isoleucine showed smaller relative increases than the other amino acids.From these results and calculations based on measurements of 2,6-diaminopimelic acid it is suggested that the extra protein in the duodenal content derives from both more efficient bacterial protein synthesis in relation to energy expended and decreased degradation of plant protein in the rumen.

Quantitative digestion of fresh herbage by sheep: IV. Protein synthesis in the stomach

1975 ◽  
Vol 84 (3) ◽  
pp. 453-458 ◽  
Author(s):  
M. J. Ulyatt ◽  
J. C. Macrae ◽  
R. T. J. Clarke ◽  
P. D. Pearce
Keyword(s):  
Protein Synthesis ◽  
Organic Matter ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Dietary Protein ◽  
Diaminopimelic Acid ◽  
Bacterial Protein ◽  
Short Rotation ◽  
Micro Organisms ◽  
Bacterial Protein Synthesis

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.

scholarly journals Utilization of low quality roughages: effects of urea and protein supplements of differing solubility on digesta flows, intake and growth rate of cattle eating oaten chaff

1980 ◽  
Vol 44 (3) ◽  
pp. 343-354 ◽  
Author(s):  
R. G. Redman ◽  
R. C. Kellaway ◽  
Jane Leibholz
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Latin Square ◽  
Live Weight ◽  
Basal Diet ◽  
The Other ◽  
Casein Diet ◽  
Bacterial Protein ◽  
Amino Acid Availability ◽  
Bacterial Protein Synthesis

1. Expt 1. Five 150 kg steers with ruminal, abomasal and ileal cannulas were given 3000 g oaten chaff daily plus prelleted supplement with no added nitrogen (diet A) or 50 g N/d as urea (diet B), casein (diet C), casein and formaldehyde-treated casein (HCHO-casein) (50:50 w/w; diet D) and HCHO-casein (diet E), in a 5 × 5 Latin square design. The basal diet and supplement were fed in eight equal increments at intervals of 3 h. Proportions of dry matter and organic matter digested in the stomach and whole tract were greater for diets B, C, D and E than for diet A. Total volatile fatty acid levels in the rumen and the proportion of acetic acid were lower, and the proportion of propionic acid higher on diet A than on the other diets. Rumen ammonia levels were lower on diets A, D and E than on diets B and C. N flows at the abomasum, ileum and rectum were lower on diet A than on the other diets; abomasal flows and apparent intestinal absorptions of amino acids were higher on diets D and E than on diets A, B and C. Efficiencies of bacterial protein synthesis were 15, 15, 14, 13 and 12 g bacterial N/kg OM truly digested in the stomach on diets A, B, C, D and E respectively.2. Expt. 2. Forty 300 kg steers were fed oaten chaffad lib.plus twice the amount of the same pelleted supplements as in Expt 1. Intake of oaten chaff was 23% higher with N supplements (diets B, C, D and E) than without (diet A). Live-weight gains were 356, 798, 843, 842 and 805 g/d on diets A, B, C, D and E respectively.3. It was concluded that efficiency of bacterial protein synthesis was not limited by the supply of peptides and amino acids in the rumen and that increases in amino acid availability in the intestines from feeding HCHO-casein did not increase food intake or live-weight gain.

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