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.

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.

Effect of starch on the utilization by sheep of a straw diet supplemented with urea and minerals

1976 ◽  
Vol 27 (1) ◽  
pp. 139 ◽  
Author(s):  
JG Mulholland ◽  
JB Coombe ◽  
WR McManus
Keyword(s):  
Organic Matter ◽  
Nitrogen Retention ◽  
Nitrogen Excretion ◽  
Digestible Organic Matter ◽  
Cellulose Digestibility ◽  
Oat Straw ◽  
Total Body ◽  
Body Energy ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

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.

Effect of abomasal infusions of methionine, casein, and starch plus methionine on the wool production of Merino wethers fed on lucerne or wheaten chaff

1974 ◽  
Vol 25 (6) ◽  
pp. 945 ◽  
Author(s):  
H Dove ◽  
GE Robards
Keyword(s):  
Body Weight ◽  
Body Weight Gain ◽  
Nitrogen Retention ◽  
Basal Diet ◽  
Nitrogen Excretion ◽  
Wool Production ◽  
Wool Growth ◽  
Quality Diet ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

Merino wethers received daily abomasal infusions of (a) 2.6 g DL-methionine, (b) 80 g casein protein or (c) 2.6 g DL-methionine plus 87 g maize starch, while consuming either lucerne chaff or wheaten chaff. Responses in wool growth, nitrogen metabolism and body weight were measured. Sheep fed on lucerne chaff had a higher urinary nitrogen excretion and nitrogen retention than those fed on wheaten chaff regardless of the presence or type of infusion. The infusion of methionine did not markedly alter these parameters from their original levels on either diet. On both diets, casein infusion led to increased urinary nitrogen excretion and nitrogen retention. Compared with sheep given starch plus methionine infusions, those given casein had higher urinary nitrogen excretion and nitrogen retention. Changes in fleece-free body weight gain followed a similar pattern. There were no pronounced differences in faecal nitrogen excretion. Regardless of the presence or type of infusion, sheep fed on lucerne grew more wool than those on wheaten chaff. On both diets, all infusions were accompanied by higher wool growths than on the basal diet alone. The effect of the casein infusion, compared with methionine infusion, was apparent only in sheep on wheaten chaff. Wool growth rates in sheep infused with starch plus methionine were not higher than the rates in the same sheep infused with methionine alone. The results suggest that the wool production of sheep will show a greater response to abomasal supplements of sulphur amino acids or casein if they are consuming a high quality diet such as lucerne chaff, compared with a low quality diet such as wheaten chaff. The apparent failure of starch infusion to stimulate wool growth above the level obtained with methionine infusions alone is discussed in relation to the interaction of protein and energy in the growth of wool.

Studies on marsupial nutrition V. the nitrogen requirements of the euro, Macropus robustus

1967 ◽  
Vol 15 (1) ◽  
pp. 7 ◽  
Author(s):  
GD Brown ◽  
A.R. Main
Keyword(s):  
Dry Matter ◽  
Arid Environment ◽  
Nitrogen Excretion ◽  
Dry Matter Intake ◽  
Dietary Nitrogen ◽  
Faecal Nitrogen ◽  
Feeding Trials ◽  
Comparison Of The Results ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

The nitrogen requirements of some female euros (Macropus robustus) were determined by means of nitrogen balance feeding trials. The average minimum dietary nitrogen requirement for the maintenance of nitrogen equilibrium was 1.99 g/day or 309 mg/day per kgW*0.73. The metabolic faecal nitrogen output of the euros, determined indirectly, was estimated to be 0.27 g/100 g dry matter intake. The minimum digestible nitrogen requirements of the euros were 160 mg/day per kgW*0.73, equivalent to approximately 1 g digestible nitrogen per day. The minimum urinary nitrogen excretion of the euros, at dietary nitrogen intakes of approximately 1 g/day, was an average of 34 mg/day per kgW*0.73. Comparison of the results obtained with data for eutherian species reported in the literature indicates that the nitrogen requirements and urinary nitrogen excretion of this species is markedly less than that of eutherian species. The results are briefly discussed in relation to survival of the euro in the arid environment of the Pilbara district of Western Australia.

Response of Yankasa sheep to various lengths of water deprivation

1981 ◽  
Vol 96 (3) ◽  
pp. 619-622 ◽  
Author(s):  
N. N. Umunna ◽  
C. N. Chineme ◽  
D. I. Saror ◽  
A. Ahmed ◽  
S. Abed
Keyword(s):  
Feed Efficiency ◽  
Water Deprivation ◽  
Nitrogen Retention ◽  
Free Water ◽  
Live Weight ◽  
Nitrogen Excretion ◽  
Severe Dehydration ◽  
Metabolism Study ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

SUMMARYThe effects of various lengths of water deprivation were studied with Yankasa sheep fed either a high roughage or a high concentrate diet in two experiments. Water was given once in 24, 48, 72 and 96 h. Free water intake decreased linearly (P < 0·01) as the period of water deprivation increased but feed intake was not similarly affected. There was a marked decrease in live-weight gain and consequently a decline in feed efficiency (kg gain/kg feed). In the metabolism study, there was a tendency towards reduced mean faecal and urinary nitrogen excretion, faecal moisture content and increased mean nitrogen retention and nitrogen and dry-matter digestibilities as the period of deprivation increased. Rams given water once in 72 and 96 h were very inactive and dull and one and three rams respectively, died of severe dehydration from those treatments in Expt 2.

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.

scholarly journals EFFECTS OF BACTERIAL ENDOTOXINS ON METABOLISM

1962 ◽  
Vol 116 (6) ◽  
pp. 897-911 ◽  
Author(s):  
L. Joe Berry ◽  
Dorothy S. Smythe ◽  
Susannah McC. Kolbye
Keyword(s):  
Nitrogen Excretion ◽  
Protein Nitrogen ◽  
Bacterial Endotoxins ◽  
Small Change ◽  
The Moment ◽  
Lower Ratio ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen

The greater susceptibility to the lethal effects of bacterial endotoxin (heat-killed Salmonella typhimurium or Escherichia coli lipopolysaccharide, in mice infected with an attenuated strain of Mycobacterium tuberculosis (BCG) was confirmed. It reached a maximum at 2 weeks postinfection and gradually diminished for an additional 6 weeks. At the time of maximum susceptibility several metabolic and physiological differences became apparent. BCG-infected mice die sooner (4 to 12 hours) and without the diarrhea, conjunctivitis, and general symptomatology associated with endotoxin deaths of normal animals. Reticuloendothelial blockade results in only a small change in reactivity to endotoxin, in contrast to normal mice. Subcutaneous injection of 2 units of ACTH is followed by no significant increase in urinary nitrogen excretion while in control animals it more than doubles. Plasma clearance of intravenously administered inulin is approximately normal in BCG-infected mice 17 hours after an LD50 dose of endotoxin but control mice similarly treated show renal impairment. In line with this result is the absence of elevated carcass non-protein nitrogen (NPN) following endotoxin poisoning or at the moment of death from endotoxemia in the hyperreactive animals in contrast to the two- to threefold increase in carcass NPN in normal mice under similar conditions. Body carbohydrate is at a minimum and becomes depleted to a level approximating that found at death more rapidly in BCG-infected mice given endotoxin than in controls. There is also a lower ratio of carbohydrate anabolized to protein catabolized following cortisone administration to BCG-infected mice than in control mice. This is found in adrenalectomized mice and in stressed animals and is reported elsewhere. Some of the differences just described can be attributed to a refractory adrenal cortex. There is less depletion of adrenal cholesterol in vivo and lower corticoid synthesis in vitro than in normal mice yet this is not fundamentally responsible for the greater susceptibility of BCG-infected animals to endotoxin since adrenalectomized mice, which are even more susceptible, are metabolically and physiologically more comparable to normal mice than to BCG-infected mice. One can conclude, therefore, that the hyperreactivity of BCG-infected mice is more than an intensification of the normal response to endotoxin.

Enteral hyperalimentation in head injury

1985 ◽  
Vol 62 (2) ◽  
pp. 186-193 ◽  
Author(s):  
Guy L. Clifton ◽  
Claudia S. Robertson ◽  
Charles F. Contant
Keyword(s):  
Head Injury ◽  
Nitrogen Balance ◽  
Severe Head Injury ◽  
Nitrogen Excretion ◽  
Metabolic Complications ◽  
Protein Nitrogen ◽  
Enteral Hyperalimentation ◽  
Lower Protein ◽  
Protein Group ◽  
Urinary Nitrogen

✓ The objectives of this study were to determine the ability of enteral hyperalimentation to meet the caloric and protein requirements in acute severe head injury, and to study the effect of increasing protein intake on nitrogen balance. This consecutive series of 20 patients suffered acute severe head injury and remained comatose for at least 24 hours. They were all without other major injuries, and were treated with steroids. These patients were randomly placed in two comparable treatment groups: one group was fed with an enteral formula containing 14% of its calories as protein and the other group received a formula containing 22% protein calories. Feedings were advanced to replace 140% of caloric expenditure measured by indirect calorimetry, averaging 3500 kcal/24 hr. Balance periods of the targeted intake were 7 days in duration, and were begun during the 1st week after injury for 65% of patients and in the 2nd week after injury for 35% of patients. The lower protein group received an average of 26.8 gm/24 hr of nitrogen, equivalent to 188 gm of protein, and the higher protein group 34.3 gm/24 hr, equivalent to 231 gm of protein. Nitrogen balance was −9.2 ± 6.7 gm/24 hr in the lower protein group and −5.3 ± 5.0 gm/24 hr in the higher protein group, but the difference did not reach statistical significance because of sample size and variability in extent of catabolism among patients. Despite the hyperalimentation, there was a mean negative cumulative nitrogen balance of 200 gm by the 2nd week after injury, and only three patients achieved net nitrogen equilibrium for the 7-day balance period. Despite enteral hyperalimentation, the patients' weight fell by 15% in the 2nd week, serum albumin was often decreased, and creatinine-height index decreased over time but remained in a normal range. Monitoring urinary urea nitrogen, which has been advocated as a generally available technique for measuring urinary nitrogen concentration, was found to be a poor measure of urinary nitrogen excretion. This work has demonstrated: 1) that high caloric and protein feedings may be delivered for prolonged periods enterally for most patients in the acute phase of head injury with few metabolic complications, and 2) that increasing the nitrogen content of feedings from 14% to 22% may somewhat improve nitrogen retention, although nitrogen equilibrium is seldom achieved.

scholarly journals Urinary Nitrogen Excretion of the Cockerels Fed Non-protein Nitrogen Diets

1974 ◽  
Vol 11 (5) ◽  
pp. 190-193 ◽  
Author(s):  
Yoshio NAKAHIRO ◽  
Yutaka ISSHIKI ◽  
Jun-ichi OKUMURA
Keyword(s):  
Nitrogen Excretion ◽  
Protein Nitrogen ◽  
Urinary Nitrogen Excretion ◽  
Urinary Nitrogen
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