scholarly journals Incorporation of 15N and 14C into amino acids of bacterial and protozoal protein in the rumen of the cow on urea-rich feed

1979 ◽  
Vol 51 (1) ◽  
pp. 497-505
Author(s):  
Eeva-Liisa Syväoja ◽  
Matti Kreula
Keyword(s):  
Amino Acids ◽  
Rumen Fluid ◽  
Sole Source ◽  
Ammonium Nitrogen ◽  
Limiting Factor ◽  
Nonprotein Nitrogen ◽  
Protein Nitrogen ◽  
Rumen Microorganisms ◽  
Low Protein ◽  
Intracellular Storage

The utilization of the non-protein nitrogen and carbon of feed by rumen microorganisms for the synthesis of protein was studied by administering [U-14C] sucrose and 15NH4Cl to a cow on urea-rich, low-protein feed. By studying the labelling of the protozoa and bacteria and the amino acids isolated from them at intervals up to 48 hours afterwards, it was found that the bacteria synthesized amino acids from nonprotein nitrogen much more rapidly and effectively than the protozoa. Also the labelling of the carbon in the amino acids of the bacteria was more rapid than in the protozoa. In both protozoa and bacteria there was intracellular storage of [14C] sucrose. Of the bacterial amino acids the most vigorous 14C labelling was found in Glu, Arg, Lys, Val and Ala and the weakest labelling in Gly, His and Ser. Of the protozoal amino acids Ala, Asp, Glu, Leu and Lys had the highest labelling and Pro, Gly, His and Phe the lowest. In the bacterial protein the labelling of Pro and Arg was ten times that of the corresponding protozoal amino acids, and Asp, Ser and Ala four times. After the 15NH4Cl dose the half-life of 15N in the rumen fluid was estimated to be 3.3 h. Labelled ammonium nitrogen was about 11 —15 % of the bacterial nitrogen and 2—3 % of the protozoal nitrogen after 1 h. Of the protozoal amino acids Ala, Glu, Val, Asp and Met had the most vigorous labelling, and of the bacterial amino acids Glu, Asp, Ser, He and Tyr. The slowest incorporation of ammonium nitrogen was into His, Pro, Arg and Gly in both bacteria and protozoa. The labelling of the bacterial amino acids was approximately 7—8 times more vigorous than that of the protozoal amino acids. The labelling of Ala was only 4 times, and that of Val, Met and Glu 5 times more vigorous than with protozoal protein. The pathway of histidine synthesis seemed to be restricted in both bacteria and protozoa and therefore may be a limiting factor in protein synthesis, particularly in cows fed urea as the sole source of nitrogen. Of the 14C and 15N label given, 12.9 and 9 % respectively was secreted in the milk during the first 3 days; over the same period the 14C and 15N excreted in the faeces plus urine accounted for 16.9 and 44.3 % respectively of that administered.

scholarly journals PROTEIN METABOLISM AND PROTEIN RESERVES DURING ACUTE STERILE INFLAMMATION

1945 ◽  
Vol 82 (1) ◽  
pp. 65-76 ◽  
Author(s):  
S. C. Madden ◽  
W. A. Clay
Keyword(s):  
Amino Acids ◽  
Nitrogen Balance ◽  
Protein Intake ◽  
Oral Feeding ◽  
Nitrogen Excretion ◽  
Protein Nitrogen ◽  
Body Protein ◽  
Low Protein ◽  
Positive Balance ◽  
Urinary Nitrogen

Adult dogs were given a proteinless diet plus casein, 80 calories/kilo, 0.4 gm. nitrogen/kilo/day. Sterile controlled inflammation was produced by subcutaneous injection of turpentine. The reaction is characterized by local swelling, induration, and abscess formation, terminated by rupture or incision after 3 to 5 days and by general reactions of malaise, fever, leucocytosis, and increased urinary nitrogen. For 3 to 6 days after turpentine the nitrogen intake was provided in seven experiments by amino acids given parenterally (a solution of the ten essential amino acids (Rose) plus glycine). A normal dog with a normal protein intake showed a negative nitrogen balance after turpentine—urinary nitrogen doubled even as in inflammation during fasting. A protein-depleted dog (low protein reserves produced by very low protein intake) given a normal protein intake after turpentine maintained nitrogen balance—urinary nitrogen rose only slightly. With a high (doubled) protein intake the depleted dog showed strongly positive balance. Normal dogs with high (doubled) protein intakes react to turpentine with doubled urinary nitrogen outputs on individual days and therefore are maintained in approximate nitrogen balance and weight balance. This end may be achieved equally well or better by oral feeding, when such is possible and absorption unimpaired. The increased nitrogen excretion after injury is again shown directly related to the state of body protein reserves. Increased catabolism not inhibition of anabolism best explains the excess urinary nitrogen. Protection during injury of valuable protein reserves appears possible through an adequate intake of protein nitrogen.

The effect of dietary protein quality on free amino acids in plasma, muscle and liver of growing chickens

1993 ◽  
Vol 57 (2) ◽  
pp. 309-318 ◽  
Author(s):  
I. Fernández-Figares ◽  
M. Lachica ◽  
L. Pérez ◽  
R. Nieto ◽  
J. F. Aguilera ◽  
...  
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Dietary Protein ◽  
Free Amino Acids ◽  
Free Amino ◽  
Protein Quality ◽  
Sole Source ◽  
Metabolizable Energy ◽  
Low Protein ◽  
Protein Diets

AbstractFree amino acid (AA) levels in plasma, muscle and liver were measured in growing chickens given either high or low protein diets varying in quality. In experiment 1, they were force-fed once a day (09.00 h), for 4 days, at about 1·5 × M level, a nitrogen-free (NF) diet and then, on day 5, they were given either diet NF or isoenergetic (13·1 kj metabolizable energy (ME) per g dry matter (DM)) and isonitrogenous high protein diets (200 g crude protein (CP) per kg) based on casein (C), lupin (L), soya bean (SB), faba bean (FB), field pea (FP), vetch (V) or bitter vetch (B) as the sole source of protein. In experiment 2, chickens were force-fed twice a day (09.00 h and 18.00 h), for 3 days, at about 1·9 × M level, with four isoenergetic (13·1 k) ME per kg DM) and isonitrogenous low protein diets (120 g CP per kg) based on SB, FP, V or B as the sole source of protein. On days 5 (experiment 1) and 4 (experiment 2) samples of plasma, muscle and liver were taken for AA analysis over 3 to 4h after morning meal.In general, within experiments, no significant differences in AA concentrations in plasma, muscle or liver among diets were found. However, there was a qualitative but not a quantitative agreement between the AA abundance in tissues and the AA rank of dietary protein. Moreover, when pooling data from experiments 1 and 2, significant regressions were found between the levels of threonine, aspartic acid, glutamic acid, glycine and proline in plasma, of lysine, alanine, glutamic acid, glycine and proline in muscle or that of proline in liver and the corresponding amounts ingested with the different diets. Under the conditions of these experiments, however, it was not possible to establish conclusively a direct relationship between the level of free amino acids in tissues and dietary protein quality.

The response of weaner pigs to a choice of foods differing in protein content

1992 ◽  
Vol 55 (2) ◽  
pp. 227-232 ◽  
Author(s):  
M. M. V. Bradford ◽  
R. M. Gous
Keyword(s):  
Amino Acids ◽  
Protein Content ◽  
Live Weight ◽  
Nutrient Content ◽  
Sole Source ◽  
Growing Pigs ◽  
Protein Food ◽  
Low Protein ◽  
Dietary Amino Acids ◽  
Amino Acid Contents

AbstractTwo experiments were designed to test the hypothesis that young growing pigs between 7 and 25 kg live weight are capable of selecting a diet which closely matches their changing requirement for amino acids, when offered a choke between two balanced foods differing only in their protein content. In the first experiment, three single-food treatments (8·6,11·7 and 17·4 g lysine per kg food) and one choice-feeding treatment (8·6 v. 17·4 g lysine per kg food), were used. In the second experiment, three foods of similar nutrient composition (approx. 14·7 g lysine per kg food) were formulated using different ingredients (fish meal, soya-bean oilcake meal and a combination of sunflower-, cottonseed- and groundnut-oilcake meals). These were fed either alone or as a choice with each other or with a low protein food (8·3 g lysine per kg food) to test whether palatability or anti-nutritional factors would override the selection based on protein alone. In both experiments, 10 pigs were housed per pen, with males and females being penned separately. One food bin with a central partition was supplied per pen, and an initial 6-day training period was used, in which pigs experienced each of the two foods on offer, separately, at daily intervals. All pigs were weighed weekly, as was the amount of food consumed in each pen. The conclusions reached were that growing pigs are able to differentiate successfully between two foods on the basis of their amino acid contents, and of changing the selected diet to match their changing requirement for dietary amino acids. However, one of the foods on offer appeared to contain either anti-nutritive factors or unpalatable components, and whereas the piglets performed as well on this as on the other foods of similar nutrient content when these foods were offered as the sole source of food, they actively selected against this food when it was offered as a choice, even if this meant their growing at a significantly slower rate than that of which they were capable.

The digestion of organic matter, nitrogen and amino acids in calves fed semi-purified diets containing urea, uric acid or soya-bean meal

1977 ◽  
Vol 89 (3) ◽  
pp. 699-710 ◽  
Author(s):  
G. J. L. Jacobs ◽  
Jane Leibholz
Keyword(s):  
Amino Acids ◽  
Organic Matter ◽  
Uric Acid ◽  
Dry Matter ◽  
Essential Amino Acids ◽  
Sole Source ◽  
Soya Bean ◽  
Protein Nitrogen ◽  
Bean Meal ◽  
Soya Bean Meal

SummarySemi-purified diets containing urea (diet A), uric acid (diet B) or soya-bean meal (diet C) as the sole source of nitrogen were fed to two Friesian bull calves fitted with re-entrant duodenal cannulae. Total collections of digesta leaving the abomasum were made over 24-h periods.The flow of organic matter to the duodenum expressed as a percentage of intake increased from 35·8% (diet A) and 40·6% (diet B) for the non-protein nitrogen diets to 58·3% for diet C. A greater proportion of the apparent digestion of organic matter occurred in the forestomachs of the calves when fed diets A or B than when they were fed diet C.The flow of nitrogen from the abomasum expressed as a percentage of intake showed a significant increase (P< 0·05) from 65·4% for diet A to 84·4% for diet B and 85·1% for diet C. When diets B and C were fed to the calves a greater proportion of the apparent digestion of nitrogen occurred in the hindgut than when they were fed diet A. The synthesis of microbial protein was 13·9 g and 13·0 g for every 100 g of organic matter digested in the stomach when the calves were fed diets B and C and only 10·9 g when the calves were fed diet A.A significantly (P< 0·05) greater proportion of dry matter of the digesta at the duodenum was composed of amino acids on diet C (19·5%) than diet A (16·1%) with the proportion of essential amino acids (especially threonine, lysine, histidine and arginine) also being greater. The amino acid composition of the digesta dry matter on diet B was intermediate (17·2%).From the data presented, it was predicted that cystine and histidine were the first limiting amino acids for growth when the calves were fed the non-protein nitrogen diets (A and B).

scholarly journals The origin of nitrogen incorporated into compounds in the rumen bacteria of steers given protein- and urea-containing diets

1979 ◽  
Vol 41 (1) ◽  
pp. 197-209 ◽  
Author(s):  
D. N. Salter ◽  
K. Daneshvar ◽  
R. H. Smith
Keyword(s):  
Amino Acids ◽  
Rumen Fluid ◽  
Exchange Chromatography ◽  
The Other ◽  
Turnover Rates ◽  
Low Protein ◽  
Protein Amino Acids ◽  
Mixed Bacteria ◽  
N Enrichment ◽  
N Rates

1. Two young Friesian steers fitted with rumen cannulas were each given three different isonitrogenous and isoenergetic diets for successive periods of 2–3 weeks. The diets consisted mainly of straw and tapioca, with the nitrogen supplied mainly as decorticated groundnut meal (DCGM; diet A), in approximately equal amounts of DCGM and urea (diet B), or entirely as urea (diet C).2. At the end of each period on a given diet, part of the dietary urea of a morning feed was replaced by a solution of [15N]urea which was infused into the rumen. Samples of rumen contents were removed just before giving the15N dose and at 1, 3, 5, 7 and 24 h afterwards, concentrations of ammonia and its15N enrichment were determined and samples of mixed bacteria were prepared. Amino acids, ammonia derived mainly from amide groups, and hexosamines were prepared by ion-exchange chromatography of acid-hydrolysates of the bacteria and analysed for15N.3. Approximate estimates of net bacterial N synthesis were made from turnover data for rumen fluid and15N enrichments in rumen fractions. From the determined efficiency of incorporation of urea-N into bacteria recovered at the duodenum, it was calculated that on diets A, B and C respectively 82%, 37% and 0% of the bacterial N was derived from dietary protein or other non-urea sources.4. [15N]urea was converted rapidly to ammonia and the15N then incorporated into bacterial amide-N; it appeared at a slower rate in total bacterial non-amide-N. Rates of incorporation into non-amide-N were highest for glutamic acid, aspartic acid and alanine, and generally lowest for proline (pro), histidine (his), phenylalanine (phe), arginine (arg), methionine (met) and galactosamine. A similar ranking was also generally observed for relative15N abundances (15N atoms %excess in N component ÷15N atoms % excess in total bacterial N) achieved after several hours. Relative15N abundances in his, arg and pro increased with decreasing protein (DCGM) in the diet but those in the other protein amino acids, including the poorly labelled met phe (and its derivative tyrosine) did not.5. It was concluded that different extents of labelling of the amino acids (at least those present mainly in protein) indicated that different amounts of preformed units (amino acids or peptides) were used. When an adequate supply of such units was available (particularly on diet A) pro, arg, his, met and phe were derived in this way to a greater extent than the other amino acids, but whereas synthesis of pro, arg and his increased on the low-protein diet C, that of met and phe did not. Thus met and phe may be limiting for bacterial growth on diets low in protein and high in non-protein-N.6. Differences in the extent of labelling of other bacterial N components may be due to different turnover rates.

Managing the rumen to limit the incidence and severity of nitrite poisoning in nitrate-supplemented ruminants

2016 ◽  
Vol 56 (8) ◽  
pp. 1317 ◽  
Author(s):  
J. V. Nolan ◽  
I. R. Godwin ◽  
V. de Raphélis-Soissan ◽  
R. S. Hegarty
Keyword(s):  
Nitric Oxide ◽  
Current Knowledge ◽  
Rumen Fluid ◽  
Reductase Activity ◽  
Ingestion Rate ◽  
Management Strategies ◽  
Management Option ◽  
Management Options ◽  
Protein Nitrogen ◽  
Rumen Microorganisms

Inclusion of nitrate (NO3−) in ruminant diets is a means of increasing non-protein nitrogen intake while at the same time reducing emissions of enteric methane (CH4) and, in Australia, gaining carbon credits. Rumen microorganisms contain intracellular enzymes that use hydrogen (H2) released during fermentation to reduce NO3− to nitrite (NO2−), and then reduce the resulting NO2− to ammonia or gaseous intermediates such as nitrous oxide (N2O) and nitric oxide (NO). This diversion of H2 reduces CH4 formation in the rumen. If NO2− accumulates in the rumen, it may inhibit growth of methanogens and other microorganisms and this may further reduce CH4 production, but also lower feed digestibility. If NO2− is absorbed and enters red blood cells, methaemoglobin is formed and this lowers the oxygen-carrying capacity of the blood. Nitric oxide produced from absorbed NO2− reduces blood pressure, which, together with the effects of methaemoglobin, can, at times, lead to extreme hypoxia and death. Nitric oxide, which can be formed in the gut as well as in tissues, has a variety of physiological effects, e.g. it reduces primary rumen contractions and slows passage of digesta, potentially limiting feed intake. It is important to find management strategies that minimise the accumulation of NO2−; these include slowing the rate of presentation of NO3– to rumen microbes or increasing the rate of removal of NO2−, or both. The rate of reduction of NO3− to NO2− depends on the level of NO3− in feed and its ingestion rate, which is related to the animal’s feeding behaviour. After NO3− is ingested, its peak concentration in the rumen depends on its rate of solubilisation. Once in solution, NO3− is imported by bacteria and protozoa and quickly reduced to NO2−. One management option is to encapsulate the NO3− supplement to lower its solubility. Acclimating animals to NO3− is an established management strategy that appears to limit NO2− accumulation in the rumen by increasing microbial nitrite reductase activity more than nitrate reductase activity; however, it does not guarantee complete protection from NO2− poisoning. Adding concentrates into nitrate-containing diets also helps reduce the risk of poisoning and inclusion of microbial cultures with enhanced NO2−-reducing properties is another potential management option. A further possibility is to inhibit NO2− absorption. Animals differ in their tolerance to NO3− supplementation, so there may be opportunities for breeding animals more tolerant of dietary NO3−. Our review aims to integrate current knowledge of microbial processes responsible for accumulation of NO2− in rumen fluid and to identify management options that could minimise the risks of NO2− poisoning while reducing methane emissions and maintaining or enhancing livestock production.

Influence of acetylation on peptide breakdown by microorganisms from the sheep rumen

1991 ◽  
Vol 1991 ◽  
pp. 46-46
Author(s):  
R.J. Wallace
Keyword(s):  
Amino Acids ◽  
Rumen Fluid ◽  
Peptide Chain ◽  
Ammonia Production ◽  
Host Animal ◽  
Rumen Microorganisms ◽  
Protein Nutrition ◽  
N Terminus ◽  
Sheep Rumen ◽  
Dipeptidyl Aminopeptidase

Protein is broken down by rumen microorganisms via peptides and amino acids to produce ammonia at rates which frequently exceed microbial requirements for N. Much of the ammonia-N formed in this way is eventually excreted as urea. If any of the steps in the degradation sequence could be inhibited, excessive ammonia production would be reduced. More protein, peptides or amino acids would escape fermentation in the rumen, thereby improving the protein nutrition of the host animal.The breakdown of peptides to amino acids is a central part of the degradation sequence. The main enzymic mechanism by which peptides are hydrolysed in the rumen is a bacterial dipeptidyl aminopeptidase, which cleaves dipeptides from the N-terminus of the peptide chain (Wallace & McKain, 1990). Little carboxypeptidase activity appears to be present. The present experiments were undertaken to find out to what extent blocking the N-terminus of peptides enables them to survive degradation in rumen fluid, and to determine which peptides can be protected in this way.

Effect of Non-protein Nitrogen Supplementation of Low-protein Layer Diets

1977 ◽  
Vol 14 (5) ◽  
pp. 250-255
Author(s):  
Hiroyuki MEKADA ◽  
Isao UMEDA ◽  
Nobuyoshi HAYASHI ◽  
Jun-ichi OKUMURA ◽  
Hiro-omi YOKOTA
Keyword(s):  
Protein Layer ◽  
Protein Nitrogen ◽  
Nitrogen Supplementation ◽  
Low Protein
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