THE ENDOGENOUS URINARY AND METABOLIC FECAL NITROGEN EXCRETIONS OF NEWBORN DAIRY CALVES

1957 ◽  
Vol 37 (2) ◽  
pp. 152-156 ◽  
Author(s):  
H. M. Cunningham ◽  
G. J. Brisson

Daily observations were made on the fecal and urinary nitrogen excretions of four calves fed nitrogen-free diets during the second and fifth weeks after birth. The endogenous urinary nitrogen excretion was equivalent to 65.3 mg. per kg. of body weight (W) per day or 186 mg. per kg. W0.72. The metabolic fecal nitrogen excretion averaged 44.0 mg. per kg. of body weight per day or 0.334 per cent of the dry matter intake.

1967 ◽  
Vol 15 (1) ◽  
pp. 7 ◽  
Author(s):  
GD Brown ◽  
A.R. Main

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.


1957 ◽  
Vol 37 (1) ◽  
pp. 95-105 ◽  
Author(s):  
F. Whiting ◽  
L. M. Bezeau

Nitrogen balance experiments were carried out with growing Yorkshire barrows to determine the influence of level of fibre (5, 10, and 15 per cent wood cellulose) in the ration, and weight of pig (15, 30, 45, and 60 kg.) on the metabolic fecal nitrogen (M.F.N.) excretion. Semi-synthetic rations containing 0.3, 5.4, 9.4, 14.0, 18.0, and 22.0 per cent protein were fed. The source of the protein was a mixture of wheat, skimmilk powder, and fishmeal. M.F.N. by direct determination on the protein-low ration (0.3 per cent protein) was compared with M.F.N. determined by extrapolation to zero protein from the other rations.An increase in the level of fibre in the ration significantly (p < 0.01) increased the M.F.N. excretion and decreased the apparent and true digestibility of the protein but had no effect on the biological value (B.V.) of the protein. As the pigs increased in weight from 15 to 50 kg., the M.F.N. excretion, per 100 gm. dry matter (D.M.) consumed, decreased in proportion to the 0.3 power of body weight, the apparent digestibility of the protein increased, and the B.V. of the protein decreased. M.F.N, per 100 gm. D.M. consumed, apparent digestibility, and B.V. of the protein did not change significantly between body weights of 50 and 65 kg.There was no significant difference between M.F.N. determined by extrapolation to zero N intake and M.F.N. determined directly by feeding a protein-low (0.3 per cent protein) ration, when the rations contained the same percentage of cellulose. The M.F.N. (gm. per 100 gm. D.M. intake) for pigs weighing an average 37 kg. was 0.10, 0.13 and 0.14 for rations containing 5, 10, and 15 per cent cellulose, respectively.Since weight of pig and the level of fibre in the ration significantly influenced the M.F.N. excretion, the latter should be determined, either directly or by extrapolation, using rations of the same fibre content and pigs of the same body weight as are used in determining the true digestibility and B.V. of proteins.


1974 ◽  
Vol 25 (6) ◽  
pp. 945 ◽  
Author(s):  
H Dove ◽  
GE Robards

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.


1960 ◽  
Vol 54 (3) ◽  
pp. 329-334 ◽  
Author(s):  
B. N. Majumdar

1. EUN and MFN excretions have been determined in goats on a N-low ration and also on a N-free ration. The values obtained were,EUN = 0·052 g./kg. live weight andMFN = 0·41 g./100 g. dry-matter feed intake.2. The values so determined with the two feeding regimens, for both the EUN and MFN agreed very closely.3. The minimum protein requirement of goats for maintenance, as calculated from the EUN value, is 0·65 lb./1000 lb. live weight.4. The formula for calculating the utilizable protein requirement for this species is found to be P = 0·89. W0.734, and is almost identical with the one given by Mitchell.5. The usefulness of the above formula in predicting the EUN of immature goats is discussed.


1957 ◽  
Vol 37 (1) ◽  
pp. 106-113 ◽  
Author(s):  
F. Whiting ◽  
L. M. Bezeau

Nitrogen balance studies were carried out on growing pigs (15 to 60 kg. body weight) using protein-low rations (approximately 0.3 per cent) to study the influence of body weight and type of fibre in the ration upon metabolic fecal and endogenous urinary nitrogen (N). The types and amounts of fibre used were: pure wood cellulose (Solka-Floc), 7 and 14 per cent of the ration; methocel, 7 and 14 per cent of the ration; and oat hulls, 14 and 28 per cent of the ration.Type and amount of fibre significantly affected the metabolic fecal N excretion of the pig, whether expressed on the basis of dry matter (D.M.) intake or fecal D.M. output. Wood cellulose (Solka-Floc) caused the greatest, and methocel the least, fecal N excretion per unit of D.M. intake. Oat hulls were intermediate.Fecal N excretion varied inversely with the 0.3 power of body weight between the body weights of approximately 15 and 60 kg.Endogenous urinary N in one experiment varied with approximately the 1.0 power of body weight, and in a second experiment with the 0.2 power of body weight. It was not possible in these experiments to determine the factors that influenced endogenous urinary N excretion.


2018 ◽  
Vol 53 (7) ◽  
pp. 858-865
Author(s):  
Clóvis Ribeiro Guimarães ◽  
Rafael Alves de Azevedo ◽  
Mariana Magalhães Campos ◽  
Fernanda Samarini Machado ◽  
Alexandre Mendonça Pedroso ◽  
...  

Abstract: The objective of this work was to evaluate the effect of reducing crude protein (CP) contents in diets with a constant metabolizable protein content on the intake, performance, nitrogen balance, and nutrient digestibility of lactating Holstein-Gyr cows. Animals (n = 24, 103±23 days in milk) were allocated to four treatments (n = 6 per group) with different CP contents: 127, 132, 139, and 156 g kg-1 dry matter (DM). DM intake was not affected by treatments. CP intake and digestibility increased linearly with higher CP contents. Milk yield (23.7±3 kg per day) and the percentages of milk protein (3.3±0.2%) and fat (3.8±0.5%) were not affected by CP reduction. Milk and blood urea nitrogen increased linearly with the increase of CP in the diet, similarly to urinary nitrogen excretion. Nitrogen use efficiency was 29.8 and 22.4% when CP was 127 and 156 g kg-1 DM, respectively. Reducing CP in diets fed to mid-lactating Holstein-Gyr cows increases nitrogen use efficiency and maintains the productive performance of the cows.


1960 ◽  
Vol 54 (3) ◽  
pp. 335-340 ◽  
Author(s):  
B. N. Majumdar

1. The crude protein requirement of goats for maintenance has been determined from balance studies. The requirement per kg., as found by three different methods of treatments of the balance data, is practically the same, viz. 2·63 g. crude protein.2. The digestible crude protein requirement also has been calculated, again by two different methods, and is estimated at 1·12 lb./1000 lb. body weight. This value is undoubtedly very much higher than the value (0·65 lb./1000 lb.) obtained previously from the endogenous urinary nitrogen determinations alone.3. The dry-matter requirement of goat per 100 lb. live weight has been determined. Calculated on the basis of live weight raised to the power 0·734, the requirement was found to be 2·6 lb./100 lb.


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