Utilization of amino acids by preruminant lambs. I. The effect of alterations in total essential amino acid intake at constant nitrogen intake

1977 ◽  
Vol 28 (5) ◽  
pp. 917 ◽  
Author(s):  
H Dove ◽  
GR Pearce ◽  
DE Tribe
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Nitrogen Balance ◽  
Control Diet ◽  
Essential Amino Acids ◽  
Conclusive Evidence ◽  
Metabolizable Energy ◽  
Nitrogen Excretion ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

Male crossbred lambs weighing 12.5 kg (period 1), 20 kg (period 2) and 30 kg (period 3) were infused per abomasum with milk-based diets in which crude protein (CP) and energy contents were constant at a given Iiveweight, but in which the proportion of CP supplied as essential amino acids (EAA) varied from 120 to 876 g EAA/kg CP. Responses in liveweight gain, nitrogen balance and metabolizable energy (ME) intake (period 1 only) were measured. A number of lambs died while receiving diets containing very high or very low proportions of EAA. Possible reasons for these deaths are discussed. In all periods liveweight gains were greatest in lambs given the control diet (513 g EAA/kg CP). In period 1 this liveweight gain was close to that expected on the basis of energy intake, but in periods 2 and 3, liveweight gains on the control diets were less than anticipated. Reductions in liveweight gain were greater for diets containing low proportions of EAA than those containing high proportions. The infusion of diets containing low proportions of EAA markedly increased urinary nitrogen excretion. The effect of diets containing high proportions was less pronounced. As a result of these effects, lambs given the control diet had the highest daily nitrogen balance in all periods. Nitrogen balance was less severely affected by the dietary changes than liveweight gain, particularly with 30 kg lambs. It is suggested that the reduced retention of apparently digested nitrogen in diets other than the control diets reflected the unsuitability of the pattern of absorbed amino acids for protein synthesis. The effect of diet on the components of energy balance in period 1 was less pronounced than its effect on nitrogen balance. The metabolizability of apparently digested energy was lower in diets other than the control diet, especially those containing low proportions of EAA. This is attributed to the energy cost of increased urinary nitrogen excretion on such diets. Alternative interpretations of the results are discussed, and it is suggested that dietary amino acids will be utilized most efficiently for protein synthesis by the tissues of the lamb when essential and non-essential amino acids are provided in approximately equal proportions. There was no conclusive evidence that this optimum proportion was different for older lambs.

Influences of diet and body condition on the nitrogen utilization in the cow

1972 ◽  
Vol 79 (2) ◽  
pp. 323-329 ◽  
Author(s):  
R. Paquay ◽  
R. De Baere ◽  
A. Lousse
Keyword(s):  
Body Condition ◽  
Nitrogen Balance ◽  
Live Weight ◽  
The Body ◽  
Metabolizable Energy ◽  
Nitrogen Excretion ◽  
Maintenance Requirements ◽  
Energy Maintenance ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

SUMMARYThe dietary and individual factors influencing the utilization of digestible nitrogen in the dry cow were studied with numerous rations fed to Friesian cows kept in metabolism stalls.Urinary nitrogen excretion and nitrogen balance were above all influenced by the level of digestible nitrogen intake. They are also correlated to metabolizable energy and digestible potassium intakes.Endogenous urinary nitrogen, estimated by extrapolation, was 30·6 mg N/kg body weight/d or 0·169 W0·73 g/d with the rations meeting approximately the energy maintenance requirements of the cow.The changes in diet accounted for 80% of the variability of nitrogen balance.A method was worked out for calculating the body condition of the cow from the live-weight variations.The changes in body condition accounted for 11% of the variability of nitrogen balance.

scholarly journals Feasibility of achieving different protein targets using a hypocaloric high-protein enteral formula in critically ill patients

Critical Care ◽  
2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Pierre Singer ◽  
Itai Bendavid ◽  
Ilana BenArie ◽  
Liran Stadlander ◽  
Ilya Kagan
Keyword(s):  
Critically Ill ◽  
Nitrogen Balance ◽  
High Protein ◽  
Nitrogen Excretion ◽  
Protein Targets ◽  
Protein Target ◽  
Group A ◽  
Group B ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

Abstract Background and aims Combining energy and protein targets during the acute phase of critical illness is challenging. Energy should be provided progressively to reach targets while avoiding overfeeding and ensuring sufficient protein provision. This prospective observational study evaluated the feasibility of achieving protein targets guided by 24-h urinary nitrogen excretion while avoiding overfeeding when administering a high protein-to-energy ratio enteral nutrition (EN) formula. Methods Critically ill adult mechanically ventilated patients with an APACHE II score > 15, SOFA > 4 and without gastrointestinal dysfunction received EN with hypocaloric content for 7 days. Protein need was determined by 24-h urinary nitrogen excretion, up to 1.2 g/kg (Group A, N = 10) or up to 1.5 g/kg (Group B, N = 22). Variables assessed included nitrogen intake, excretion, balance; resting energy expenditure (REE); phase angle (PhA); gastrointestinal tolerance of EN. Results Demographic characteristics of groups were similar. Protein target was achieved using urinary nitrogen excretion measurements. Nitrogen balance worsened in Group A but improved in Group B. Daily protein and calorie intake and balance were significantly increased in Group B compared to Group A. REE was correlated to PhA measurements. Gastric tolerance of EN was good. Conclusions Achieving the protein target using urinary nitrogen loss up to 1.5 g/kg/day was feasible in this hypercatabolic population. Reaching a higher protein and calorie target did not induce higher nitrogen excretion and was associated with improved nitrogen balance and a better energy intake without overfeeding. PhA appears to be related to REE and may reflect metabolism level, suggestive of a new phenotype for nutritional status. Trial registration 0795-18-RMC.

Branched-Chain Amino Acids, Nitrogen Excretion and Injury in Man

1976 ◽  
Vol 50 (5) ◽  
pp. 393-399 ◽  
Author(s):  
J. H. Wedge ◽  
R. De Campos ◽  
A. Kerr ◽  
R. Smith ◽  
Rose Farrell ◽  
...  
Keyword(s):  
Amino Acids ◽  
Venous Blood ◽  
Branched Chain Amino Acids ◽  
Nitrogen Excretion ◽  
Adult Males ◽  
Blood Concentrations ◽  
Branched Chain ◽  
Injured Patients ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

1. Venous blood concentrations of the branched-chain amino acids, valine, leucine and isoleucine, and urinary nitrogen excretion have been measured in sixteen adult males, from 2 h to 7 days after injury, and in four adults after elective skin grafts. 2. In the injured group the concentrations of these amino acids rose significantly 24 h after injury and had doubled at 4 days and remained high; in contrast the skin-graft patients showed no significant change. 3. In those injured patients with initial hyperketonaemia, defined as more than 0·2 mmol/l, the increase in concentrations of branched-chain amino acids at the fourth and seventh days after injury was significantly less than in those with normoketonaemia, and was accompanied by lower urinary nitrogen excretion throughout the whole period. 4. It is suggested that the changes in the concentration of branched-chain amino acids after injury indicate decreased uptake by muscle or excessive release due to an imbalance between protein synthesis and protein catabolism in this tissue.

Aspects of nitrogen utilization in Asiatic water buffalo and Zebu cattle

1983 ◽  
Vol 100 (1) ◽  
pp. 13-23 ◽  
Author(s):  
J. B. Moran
Keyword(s):  
Nitrogen Balance ◽  
Water Buffalo ◽  
Energy Content ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Nitrogen Excretion ◽  
Zebu Cattle ◽  
Dietary Nitrogen ◽  
Faecal Nitrogen ◽  
Urinary Nitrogen

SUMMARYThe results of 62 comparative digestibility and nitrogen balance trials of Asiatic water buffalo and Zebu cattle fed the same roughage or mixed diet were analysed to test for species differences in various nitrogen input-output relationships. The influence of dietary metabolizable energy content on the utilization of dietary or apparently digested nitrogen (ADN) was also investigated.There was no difference between buffaloes and Zebus in their ability to digest dietary nitrogen. The true nitrogen digestibility was calculated to be 81% and the metabolic faecal nitrogen excretion to be 0·36 g N/lOOg dry-matter intake. The buffaloes had lower rates of excretion of urinary nitrogen per unit increase in ADN, and at the same intake of ADN (143 mg/kg live weight/day), they had the higher nitrogen balance: 58v.48 mg/kg live weight/day. Dietary metabolizable energy content did not affect the utilization of digested nitrogen.Estimates of metabolic faecal nitrogen and endogenous urinary nitrogen excretions and of maintenance requirements for digested nitrogen were similar to those of tropical large ruminants reported by other workers. On low-quality (0·8% N) or medium-quality (1·6% N) diets, it was calculated that buffaloes would have nitrogen balances.

scholarly journals Levels of protected lysine and methionine in the diet of lambs: nutritional parameters and protein metabolites

2019 ◽  
Vol 40 (6Supl3) ◽  
pp. 3709
Author(s):  
Carolina Moreira Araújo ◽  
Gilberto de Lima Macedo Junior ◽  
Karla Alves Oliveira ◽  
Adriana Lima Silva ◽  
Marco Túlio Santos Siqueira
Keyword(s):  
Amino Acids ◽  
Nitrogen Balance ◽  
Latin Square ◽  
Nitrogen Excretion ◽  
Average Weight ◽  
Nutritional Parameters ◽  
Ruminal Degradation ◽  
Five Phases ◽  
Different Levels ◽  
Urinary Nitrogen Excretion

The objective of this study was to evaluate the effect of inclusion of different levels of protected lysine and methionine on the nutritional parameters and protein metabolites of lambs. The experiment was carried out at the Capim Branco Experimental Farm, at Uberlândia Federal University, during the months of September and October 2016. Five blood lambs ½ Dorper × ½ Santa Inês, approximately eight months old and with an average weight of 50 kg, were distributed in a Latin square scheme 5 × 5 (five treatments and five replicates). The treatments consisted of the inclusion in the diet of different levels of lysine and methionine protected from ruminal degradation (MicroPEARLS LM®): 0 g, 8 g, 16 g, 24 g, and 32 g. The diet was composed of corn silage and concentrate in a ratio of 30V:70C. The experiment was divided into five phases. Each phase had a duration of fifteen days (ten days of adaptation of the animals to the experimental diets and five days of data collection). The animals were kept in individual metabolic cages. A digestibility assay was performed to determine the apparent dry matter intake and digestibility (DMI/DDMI), nitrogen balance, and protein metabolites. The DMI (kg day-1) and in relation to the metabolic weight presented a positive linear equation, and was highest for the treatment with 32 g of amino acids, as well as the ingested nitrogen and nitrogen balance, being positive in all treatments. There was no difference (P > 0.05) in the DDMI. The crude protein and urea concentrations remained above the recommended levels and the concentration of creatinine remained below the recommended level. The inclusion of protected amino acids up to 32 g increases DMI and urinary nitrogen excretion without negatively affecting digestibility. The protein metabolism was altered, without causing damage to the performance of the animals.

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.

Urea and meat meal in the diets of ruminant calves - the sites of digestion and the nitrogen requirements for microbial protein synthesis

1980 ◽  
Vol 31 (1) ◽  
pp. 163 ◽  
Author(s):  
J Leibholz
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Nitrogen Content ◽  
Energy Content ◽  
Essential Amino Acids ◽  
Metabolizable Energy ◽  
Sulfur Amino Acids ◽  
Microbial Protein ◽  
Microbial Protein Synthesis ◽  
Meat Meal

Nine Friesian calves between 11 and 30 weeks of age were fed on diets based on barley supplemented with 0, 1.75 or 3.5 % urea or with meat meal. In a further experiment a purified diet was supplemented with 3-5.25 % urea and 20-50% wheat straw. The replacement of meat meal by urea reduced the flow of nitrogen to the duodenum and the apparent absorption of amino acid in the intestines. It was calculated that diets containing no meat meal would be limiting the growth of calves by a deficiency of sulfur amino acids and possibly threonine. With purified diets it was also calculated that the sulfur amino acids would be the first limiting amino acids for growth. The apparent digestion of amino acids in the small intestine varied from 66 to 76% for diets containing at least 1.8% nitrogen. The apparent digestion of essential amino acids was greater than that of non-essential amino acids. A nitrogen content of 1.8 % as urea in a purified diet was sufficient to maximize the efficiency of microbial protein synthesis in the rumen to 23-24 g nitrogen per kg of dry matter fermented. This is equivalent to 1.7 g nitrogen per MJ of metabolizable energy in the diet and corresponds to a concentration of ammonia in the rumen of 120 mg/l. The dietary nitrogen content required in barley and urea diets for maximum microbial protein synthesis was greater than with purified diets owing to the incomplete breakdown of the nitrogen in barley in the rumen. The efficiency of microbial protein synthesis in the rumen was similar for diets containing 8.3-11.0 MJ of metabolizable energy per kg of diet. The apparent digestion of a-linked glucose polymers in the rumen was lower for diets containing 1.3 % nitrogen than for those containing at least 1.8 %. As the metabolizable energy content of diets increased, there was a decrease in the apparent digestion of a-glucose polymers in the rumen.

Utilization of amino acids by preruminant lambs. II.* The effects of independent alterations in total nitrogen and total essential amino acid intake

1977 ◽  
Vol 28 (5) ◽  
pp. 933 ◽  
Author(s):  
H Dove ◽  
GR Pearce ◽  
DE Tribe
Keyword(s):  
Amino Acids ◽  
Energy Intake ◽  
Total Nitrogen ◽  
Nitrogen Balance ◽  
Crude Protein ◽  
Three Dimensional ◽  
Essential Amino Acids ◽  
Metabolizable Energy ◽  
Nitrogen Intake ◽  
Metabolizable Energy Intake

Male crossbred lambs weighing 12.5 kg were infusedper abomasum with milk-based diets containing 259, 209 or 175 g crude protein (CP)/kg dry matter. The proportion of crude protein supplied as essential amino acids (EAA) was also varied, to provide diets containing 414, 512 or 613 g EAA/kg CP. This allowed an estimation of the effects of independent alterations in total EAA intake and total nitrogen intake on rates of liveweight gain, and on daily nitrogen balance and metabolizable energy intake. At a given proportion of EAA in crude protein, reductions in the EAA intake reduced the rate of liveweight gain, especially when diets contained 414 or 613 g EAA/kg CP. At constant EAA intake, rates of liveweight gain were reduced when the nitrogen intake was such that the dietary proportion of EAA departed from 512 g/kg CP. Responses in nitrogen balance were similar to those in liveweight gain except that, at constant EAA intake, increases in nitrogen intake improved nitrogen balance. All nitrogen balance responses were less pronounced than liveweight gain responses. Lambs given diets containing 414 or 613 g EAA/kg CP had lower metabolizable energy intakes. This was not due to reduced metabolizability of apparently digested energy, but to differences in apparently digested energy intake. The relative effects of nitrogen intake and the proportion of crude protein supplied as EAA, on liveweight gain and nitrogen balance are assessed by using three-dimensional representations of the responses. ___________________ Part I,Aust. J. Agric. Res., 28: 917 (1977).

scholarly journals PLASMA PROTEIN PRODUCTION INFLUENCED BY AMINO ACID MIXTURES AND LACK OF ESSENTIAL AMINO ACIDS

1945 ◽  
Vol 82 (2) ◽  
pp. 77-92 ◽  
Author(s):  
S. C. Madden ◽  
F. W. Anderson ◽  
J. C. Donovan ◽  
G. H. Whipple
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Plasma Protein ◽  
Protein Production ◽  
Daily Intake ◽  
Essential Amino Acids ◽  
Nitrogen Excretion ◽  
Acid Mixture ◽  
Rapid Weight Loss ◽  
Urinary Nitrogen

When blood plasma proteins are depleted by bleeding with return of red cells suspended in saline (plasmapheresis) it is possible to bring dogs to a steady state of hypoproteinemia and a constant level of plasma protein production if the diet nitrogen intake is controlled and limited. Such dogs are outwardly normal but have a lowered resistance to infection and intoxication and probably to vitamin deficiency. When the diet nitrogen is provided by certain mixtures of the ten growth essential amino acids plus glycine, given intravenously at a rapid rate, plasma protein production is good. The same mixture absorbed subcutaneously at a slower rate may be slightly better utilized. Fed orally the same mixture is better utilized and associated with a lower urinary nitrogen excretion. An ample amino acid mixture for the daily intake of a 10 kilo dog may contain in grams dl-threonine 1.4, dl-valine 3, dl-leucine 3, dl-isoleucine 2, l(+)-lysine·HCl·H2O 2.2, dl-tryptophane 0.3, dl-phenylalanine 2, dl-methionine 1.2, l(+)-histidine·HCl·H2O 1, l(+)-arginine·HCl 1, and glycine 2. Half this quantity is inadequate and not improved by addition of a mixture of alanine, serine, norleucine, proline, hydroxyproline, and tyrosine totalling 1.4 gm. Aspartic acid appears to induce vomiting when added to a mixture of amino acids. The same response has been reported for glutamic acid (8). Omission from the intake of leucine or of leucine and isoleucine results in negative nitrogen balance and rapid weight loss but plasma protein production may be temporarily maintained. It is possible that leucine may be captured from red blood cell destruction. Tryptophane deficiency causes an abrupt decline in plasma protein production. No decline occurred during 2 weeks of histidine deficiency but the urinary nitrogen increased to negative balance. Plasma protein production may be impaired during conditions of dietary deficiency not related to the protein or amino acid intake. Skin lesions and liver function impairment are described. Unidentified factors present in liver and yeast appear to be involved.

Studies on marsupial nutrition. VI. The utilization of dietry urea by the Euro or Hill Kangaroo, Macropus robustus (Gould)

1969 ◽  
Vol 17 (2) ◽  
pp. 187 ◽  
Author(s):  
GD Brown
Keyword(s):  
Nitrogen Balance ◽  
Dietary Protein ◽  
Nitrogen Retention ◽  
Nitrogen Excretion ◽  
Microbial Protein ◽  
Digestive Physiology ◽  
Protein Nitrogen ◽  
Feeding Trials ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

Macropod marsupials, the kangaroos and wallabies, are characterized by a ruminant-like digestive physiology. One feature of digestion in eutherian species of ruminants is the ability of these animals to utilize non-protein nitrogen through the conversion of such nitrogen to microbial protein by the microorganisms in the rumen. In the present experiments with the euro or hill kangaroo (M. robustus), the utilization of dietary protein (casein) and non-protein nitrogen (urea) has been compared by means of nitrogen balance feeding trials. No consistent differences between the levels of nitrogen retention and urinary nitrogen excretion were observed for euros fed rations supplemented with either casein or urea. It is suggested that the digestion of nitrogen by the ruminant-like macropod marsupials is similar to that of eutherian species of ruminant herbivores.

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