Amino and urea nitrogen levels in lambs receiving different nitrogen sources and injections of lysine and methionine

1969 ◽  
Vol 47 (11) ◽  
pp. 929-934 ◽  
Author(s):  
D. G. Ely ◽  
C. O. Little ◽  
G. E. Mitchell Jr.
Keyword(s):  
Amino Acid ◽  
Amino Nitrogen ◽  
Nitrogen Sources ◽  
Total Amino Acid ◽  
Urea Nitrogen ◽  
Plasma Urea ◽  
Nitrogen Levels ◽  
Dietary Nitrogen ◽  
Tissue Protein Synthesis ◽  
Time Of Feeding

Two trials were conducted to study changes in plasma urea and amino nitrogen of lambs fed different nitrogen sources. In the first trial, zein, zein and urea, or urea were fed as the only dietary nitrogen sources. Nitrogen balance data indicated the superiority of the zein–urea ration. Plasma amino acid concentrations were lower at 4 h after feeding than just before feeding. The concentration of total plasma amino acids was greatest when zein was fed and least when the zein–urea ration was fed. Lysine injections into the systemic blood caused a steady decline in total amino acid concentration up to 60 min after injection when zein was fed. Increases in total concentrations were noted after injection when urea had been fed. Intermediate values resulted in lambs fed the zein–urea ration. Lysine appeared to be the limiting amino acid required for maximum tissue protein synthesis when zein was fed. In the second trial, zein, purified soy protein, urea plus sulfur, and urea without sulfur were fed. Plasma collected from lambs fed zein contained less urea nitrogen at every collection period than those fed the other three nitrogen sources. Urea nitrogen decreased from time of feeding to 4 h after feeding zein and soy but increased after feeding both urea rations. Plasma amino nitrogen decreased from time of feeding to 4 h after feeding all rations. Neither urea nitrogen nor amino nitrogen was affected by intravenous amino acid injections.

The effect of urea in the diet of the early-weaned calf on weight gain, nitrogen and sulphur balance, and plasma urea and free amino acid concentrations

1971 ◽  
Vol 22 (4) ◽  
pp. 655 ◽  
Author(s):  
J Leibholz ◽  
RW Naylor
Keyword(s):  
Blood Plasma ◽  
Control Diet ◽  
Nitrogen Concentration ◽  
Amino Nitrogen ◽  
Urea Nitrogen ◽  
Plasma Urea ◽  
Dietary Nitrogen ◽  
Meat Meal ◽  
Nitrogen Intake ◽  
Amino Acid Concentrations

Experiments were conducted with 40 male Friesian calves between 5 and 11 weeks of age. The control diet contained meat meal as the sole protein supplement to grain, and this was replaced by urea to supply 20.1, 39.2, or 55.6% of the dietary nitrogen. The growth rate of the calves, when corrected for digestible dry matter intake, was significantly lower when urea supplied 55.6 % of the dietary nitrogen than when it supplied 0, 20.1, or 39.2% of the dietary nitrogen. The retention of nitrogen and sulphur was lower in the calves given 55.6% of the dietary nitrogen as urea, but the ratio of nitrogen to sulphur retained was constant for all diets. There was a positive correlation between dietary urea nitrogen intake and urea nitrogen concentration in the blood plasma. The urea nitrogen and a-amino nitrogen concentration in the blood plasma was greater in calves at 2 weeks of age than at 11 weeks of age. The concentrations of free glycine, valine, leucine, ornithine, lysine, and histidine in the blood plasma were significantly lower in the calves given the higher levels of urea in the diet.

Effects of acute cold exposure on muscle amino acid and protein in rats

1982 ◽  
Vol 52 (5) ◽  
pp. 1250-1256 ◽  
Author(s):  
O. L. Smith ◽  
G. Huszar ◽  
S. B. Davidson ◽  
E. Davis
Keyword(s):  
Amino Acid ◽  
Cold Exposure ◽  
Muscle Protein ◽  
Serum Insulin ◽  
Amino Nitrogen ◽  
Streptozotocin Diabetes ◽  
Total Amino Acid ◽  
Protein Breakdown ◽  
Amino Acid Release ◽  
Acid Release

To test the effects of acute cold on muscle amino acid and protein 1) rats were exposed to 4 degrees C for 24 h, functionally hepatectomized (eviscerated) and accumulation in the blood used to indicate changes in amino acid release from the tissues; 2) other rats were left intact, and urinary excretion of 3-methylhistidine (proportional to muscle protein breakdown) determined during cold exposure. In the eviscerated group, cold enhanced loss of total amino acids from the tissues (as alpha-amino nitrogen), but the loss (213 +/- 14.8% of basal in 2 h) was not due to excess alanine (180 +/- 8.5%). By comparison, in fasted rats total amino acid was 182 +/- 12.3, alanine 309 +/- 17.2%. Also, the cold-induced loss resembled the effects of streptozotocin diabetes and depended on a depression by cold of serum insulin (to 35.7 +/- 2.3 muU/ml). Therefore it was prevented when insulin was restored by infusion (40 mU . 100 g-1 . h-1) or by adrenodemedullation before cold exposure. Epinephrine (10 micrograms/100 g sc) depressed insulin in the latter and permitted amino acid release to recur. In intact rats, 3-methylhistidine excretion was unaffected by cold. The results suggest that although cold fails to stimulate alanine synthesis or protein breakdown, it inhibits insulin release sympathetically, thereby diminishing the amount of amino acid incorporated into muscle protein.

RATE OF PROTEIN DEGRADATION AND NUTRIENT DIGESTION OF VARIOUS NITROGEN SOURCES IN CONTINUOUS CULTURE OF RUMEN CONTENTS

1987 ◽  
Vol 67 (3) ◽  
pp. 745-756 ◽  
Author(s):  
J. E. GARRETT ◽  
R. D. GOODRICH ◽  
M. D. STERN ◽  
J. C. MEISKE
Keyword(s):  
Amino Acid ◽  
Protein Degradation ◽  
Continuous Culture ◽  
Soybean Meal ◽  
Nitrogen Sources ◽  
Total Amino Acid ◽  
Linseed Meal ◽  
Corn Gluten Meal ◽  
Corn Gluten ◽  
Dietary Amino Acid

A dual flow continuous culture fermentor system was used to estimate ruminal rate of protein degradation and influence of supplemental nitrogen (N) source on digestion of total dietary crude protein (CP), dry matter (DM) and organic matter (OM). Four experimental diets contained predominantly corn and were isocaloric (14.7 M J DE kg−1) and isonitrogenous (12% CP on a DM basis) with urea, soybean meal (SBM), linseed meal (LSM) or corn gluten meal (CGM) as sole supplemental N sources. Fermentor flow rates were adjusted daily to attain liquid and solid dilution rates of 10 and 5% h−1, respectively. Total dietary N digestibility was greater (P < 0.05) in fermentors receiving urea than in those receiving CGM, while fermentors receiving SBM or LSM were intermediate (72.9, 54.9, 64.0 and 63.2%, respectively). Bacterial CP flow was higher (P < 0.05) from fermentors receiving urea or SBM than from those receiving CGM, with fermentors receiving LSM intermediate (1.31, 1.29, 1.02 and 1.14 g d−1, respectively). True OM digestibility was greater (P < 0.05) for diets supplemented with urea or LSM than for those supplemented with CGM (65.1, 60.4 and 51.2%, respectively). The rate of protein degradation was greater (P < 0.05) for LSM-CP than CGM-CP with SBM-CP intermediate (15.73, 6.88 and 10.13% h−1, respectively). Calculated bypass of potentially digestible protein for SBM-CP, LSM-CP and CGM-CP was 15.9, 10.9 and 29.1%, respectively. Total amino acid flow (g d−1) was higher (P < 0.05) for fermentors receiving SBM than for those receiving LSM. Total bacterial amino acid flow (g d−1) was higher (P < 0.05) for fermentors receiving SBM than for fermentors receiving CGM. Differences among diets for dietary amino acid flow (g d−1) were not significant. Key words: Ruminal protein degradation, soybean meal, linseed meal, corn gluten meal, continuous culture system

GROWTH-DEPENDENT CHANGES IN BLOOD UREA NITROGEN LEVELS IN LINCOLN AND SOUTHDOWN LAMBS

1969 ◽  
Vol 49 (2) ◽  
pp. 197-204 ◽  
Author(s):  
H. Mukhoty ◽  
W. Combs ◽  
T. D. D. Groves
Keyword(s):  
Body Weight ◽  
Blood Plasma ◽  
Blood Urea Nitrogen ◽  
Growth Period ◽  
Urea Nitrogen ◽  
Plasma Urea ◽  
Nitrogen Levels ◽  
Rate Of Increase

The concentration of blood plasma urea nitrogen (BUN) was measured at bi-weekly intervals in four groups of growing Lincoln and Southdown lambs which received the same ration throughout their growth period. BUN increased with age and weight in each group. Although all groups showed similar changes in BUN with age, BUN concentration increased at 0.73 × 10−2, 0.88 × 10−2, 0.91 × 10−2, and 1.23 × 10−2 mg per kg of body weight gained in the case of Lincoln males, Lincoln females, Southdown males, and Southdown females, respectively. The average rates of gain for these groups were 0.33, 0.28, 0.26 and 0.20 kg per day, respectively. It appeared from these studies that at any given weight, the more mature animals at that weight tended to have higher BUN concentrations and a higher rate of increase of BUN with weight.

scholarly journals Plasma urea nitrogen as an indicator of amino acid imbalance in rabbit diets

2020 ◽  
Vol 28 (2) ◽  
pp. 63
Author(s):  
Pablo Jesús Marín-García ◽  
María del Carmén López-Luján ◽  
Luís Ródenas ◽  
Eugenio Melchor Martínez-Paredes ◽  
Enrique Blas ◽  
...  
Keyword(s):  
Amino Acid ◽  
Feed Efficiency ◽  
Dry Matter ◽  
Urea Nitrogen ◽  
Plasma Urea ◽  
Dietary Amino Acid ◽  
Amino Acid Imbalance ◽  
Ad Libitum ◽  
Amino Acid Balance ◽  
Current Guidelines

<p>In recent decades, recommendations on dietary protein content have been considerably reduced, while fibre content has been increased. Under these conditions, an adequate dietary amino acid balance could be crucial to optimise feed efficiency. Plasma urea nitrogen (PUN) level could be a good indicator of an amino acid imbalance and its potential has already been studied in other species, but not yet in rabbits. The main objective of the present work was to detect the possible interest of PUN in pinpointing amino acid deficiencies in rabbits. Two experimental diets were formulated from the same basal mixture, following all the recommendations for growing rabbits, except lysine, whose content was variable, following current guidelines in diet P8.1 or lower from those in P4.4 (with 8.1 and 4.4 g/kg dry matter of lysine and with 757 and 411 mg of lysine per MJ of digestible energy). Three different trials were designed: one where the animals were fed &lt;em&gt;ad libitum&lt;/em&gt; (AL) and two others in which fasting periods of 10 h were included; one where feeding was restored at 08:00 h (Fast8h) and the other at 18:00 h (Fast18h). A total of 72 three-way crossbred growing rabbits (24 animals for each trial in a split-plot trial) up to a total of 12 recordings were used. Blood samples were taken every 4 h in AL trial and every hour after refeeding up to a total of six controls, in trials Fast8h and<br />Fast18h. The differences between balanced and unbalanced diets in lysine were highest (&lt;em&gt;P&lt;/em&gt;&lt;0.001) between 04:00 h and 12:00 h in animals fed ad libitum, and at 3 h after refeeding (21:00 h) in Fast18h. These results suggest that PUN could be an adequate indicator to detect deficiencies in amino acids in growing rabbit<br />diets.</p>

Amino acid nutrition of the lactating sow: the requirement for dietary lysine

1982 ◽  
Vol 35 (1) ◽  
pp. 15-23 ◽  
Author(s):  
R. Wilkinson ◽  
D. J. A. Cole ◽  
D. Lewis
Keyword(s):  
Amino Acid ◽  
Linear Regression ◽  
Dry Matter ◽  
Latin Square ◽  
Basal Diet ◽  
Milk Composition ◽  
Nutritional Adequacy ◽  
Urea Nitrogen ◽  
Plasma Urea ◽  
Lactating Sow

ABSTRACTThe lysine requirement of the lactating sow was examined in two Latin-square experiments using multiparous sows, in mid lactation, each of which suckled a litter of 10 piglets. The lysine requirement was examined by the addition of supplementary synthetic lysine to a basal diet deficient in lysine, to give dietary lysine levels of 6·4 to 17·2g/kg dry matter. The adequacy of the lysine supply was judged by the responses of plasma lysine, plasma and urea-nitrogen, urinary urea-nitrogen and milk composition. Intersecting linear regression lines were fitted to the treatment means. The responses of urinary urea-nitrogen, in the two experiments, indicated that the lactating sow required approximately 48·5 g dietary lysine per day while the response of plasma lysine indicated a requirement of approximately 51 g lysine per day. Plasma urea and milk composition were less useful as indicators of the nutritional adequacy than were urinary urea-nitrogen and plasma lysine.

Renal responses to amino acids in the sheep fetus

1996 ◽  
Vol 270 (6) ◽  
pp. R1226-R1230 ◽  
Author(s):  
L. L. Woods ◽  
A. R. Hohimer ◽  
L. E. Davis
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Intake ◽  
Amino Nitrogen ◽  
Maternal Plasma ◽  
Fetal Sheep ◽  
Acid Infusion ◽  
Amino Acid Infusion ◽  
Nitrogen Levels ◽  
Amino Acid Levels

Adult animals and humans are known to increase renal blood flow and glomerular filtration rate (GFR) in response to an acute protein load or amino acid infusion; however, the ontogeny of this phenomenon is not known. This study was designed to test the hypothesis that, despite normally high baseline amino acid levels in the fetus, increases in plasma amino acids stimulate increases in GFR before birth. Eight chronically instrumented fetal sheep (126 +/- 1 days gestation) were infused with a mixture of amino acids (0.15 and 0.30 mmol . kg-1 . min-1 i.v.). Plasma alpha-amino nitrogen levels increased significantly from 7.1 +/- 0.3 to 13.0 +/- 0.9 and 25.5 +/- 2.1 mg/dl, respectively, in response to the two doses, and GFR increased significantly from 3.2 +/- 0.4 to 4.0 +/- 0.5 and 4.6 +/- 0.5 ml/min, respectively. Arterial pressure did not change. Renal amino acid reabsorption was significantly increased at all time points during the amino acid infusion, reaching a value nearly five times that of control by the last clearance period. Na+ reabsorption was also increased throughout the infusion. Na+, K+, and Cl- excretions increased significantly only at the very last time point. These data indicate that the mechanism or mechanisms responsible for amino acid-induced hyperfiltration are present and functional even before birth in the sheep. Because maternal eating patterns and protein intake are known to change maternal plasma amino acid levels and amino acids are actively transported across the placenta, our findings suggest that both acute and chronic changes in maternal protein intake may alter fetal renal function.

Sign in / Sign up

Export Citation Format

Share Document