scholarly journals Nitrogen and purine metabolism at varying energy and protein supplies in sheep sustained on intragastric infusion

1990 ◽  
Vol 64 (2) ◽  
pp. 359-370 ◽  
Author(s):  
J. E. Lindberg ◽  
K.-G. Jacobsson
Keyword(s):  
Urinary Excretion ◽  
Energy Intake ◽  
Protein Intake ◽  
Energy Supply ◽  
Volatile Fatty Acids ◽  
Purine Derivatives ◽  
Plasma Urea ◽  
N Retention ◽  
Gross Energy ◽  
N Requirement

Wether sheep were fitted with rumen fistulas and polyethylene tubes to the abomasum and were given all nutrients by intragastric infusion. In Expt 1 volatile fatty acids (VFA) were given at 340, 450 and 630 kJ gross energy (GE)/kg metabolic weight (W0.75) and protein at 0, 150, 300, 600, 900 and 1500 mg nitrogen/kg W0.75. In Expt 2 VFA were infused at 450 kJ GE/kg W0.75 and protein at 0 and 300 mg N/kg W0.75. At all levels of energy intake in Expt 1 the N retention was significantly (P < 0.01) related to N intake. The basal N requirement was estimated to be 281 mg (SE 21.8) N/kg W0.75 at 340 kJ VFA/kg W0.75, 226 (SE 21.8) mg N/kg W0.75 at 450 kJ VFA/kg W0.75 and 207 (SE 19.4) mg N/kg W0.75 at 630 kJ VFA/kg W0.75. Plasma urea concentrations varied markedly in relation to protein intake and to energy supply. On the other hand plasma ammonia, glucose, insulin and creatinine concentrations, and also urinary excretion of purine derivatives and creatinine were not significantly affected by the treatments imposed. It was concluded that the urinary excretion of purine derivatives in ruminants was largely unaffected by moderate changes in energy intake and by large changes in protein intake.

scholarly journals Investigation of nitrogen balance in dairy cows and steers nourished by intragastric infusion

1983 ◽  
Vol 50 (1) ◽  
pp. 99-107 ◽  
Author(s):  
E. R. Ørskov ◽  
N. A. MacLeod ◽  
S. T. M. Fahmy ◽  
L. Istasse ◽  
F. D. DeB. Hovell
Keyword(s):  
Fatty Acids ◽  
Dairy Cows ◽  
Energy Supply ◽  
Volatile Fatty Acids ◽  
Energy Content ◽  
The Other ◽  
N Balance ◽  
Zero Energy ◽  
Gross Energy ◽  
Practical Implications

1. Two dairy cows were maintained by intragastric infusion of volatile fatty acids and casein. Except when fasting, the casein-nitrogen was held constant, while total gross energy supply was varied from zero during fasting to 650 kJ/kg body-weight (W)0·75.2. One cow was estimated to attain zero N balance at an energy intake of 255 kJ/kg W0·75and the other at 307 kJ/kg W0·75, which was calculated to be substantially below the estimated energy required for zero energy balance.3. When the cows were later given an N-free infusion for a period preceding the trial, N balance occurred at 98 kJ/kg W0·75for one cow and 115 kJ/kg W0·75for the other.4. Four steers were similarly nourished by intragastric infusion and the energy nutrient increased from 0 at fasting to 450 kJ/kg W0·75. The protein was held constant at 1 g N/kg W0·75except at fasting. The energy level at which N balance occurred was 154 (SE 38) kJ/kg W0·75or approximately equal to the energy content of the protein. The practical implications of these findings are discussed.

scholarly journals Excretion of purine derivatives by ruminants: recycling of allantoin into the rumen via saliva and its fate in the gut

1990 ◽  
Vol 63 (2) ◽  
pp. 197-205 ◽  
Author(s):  
X. B. Chen ◽  
F. D. DeB. Hovell ◽  
E. R. ØRskov
Keyword(s):  
Fatty Acids ◽  
Uric Acid ◽  
Urinary Excretion ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Purine Derivatives ◽  
Complete Destruction ◽  
Series Of Experiments ◽  
Micro Organisms

The saliva of sheep was shown to contain significant concentrations of uric acid (16 (sd) 4.5) μmol/l) and allantoin (120 (sd 16.4) μmol/l), sufficient to recycle purine derivatives equivalent to about 0.10 of the normal urinary excretion. When allantoin was incubated in vitro in rumen fluid, it was degraded at a rate sufficient to ensure complete destruction of recycled allantoin. In a series of experiments in which allantoin was infused into the rumen of sheep fed normally, or into the rumen or abomasum of sheep and the rumen of cattle completely nourished by intragastric infusion of volatile fatty acids and casein, no additional allantoin was recovered in the urine. These losses were probably due to the degradation of allantoin by micro-organisms associated with the digestive tract. It is concluded that all allantoin and uric acid recycled to the rumen via saliva will be similarly degraded. Therefore, the use of urinary excretion of purine derivatives as an estimator of the rumen microbial biomass available to ruminants will need to be corrected for such losses.

COMPARATIVE VALUE OF SOYBEAN, RAPESEED, AND FORMALDEHYDE-TREATED RAPESEED MEALS IN UREA-CONTAINING CALF RATIONS

1973 ◽  
Vol 53 (2) ◽  
pp. 273-278 ◽  
Author(s):  
H. R. SHARMA ◽  
J. R. INGALLS
Keyword(s):  
Dry Matter ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Rapeseed Meal ◽  
Feed Consumption ◽  
Feed Conversion ◽  
Plasma Urea ◽  
Gross Energy ◽  
Holstein Calves ◽  
Molar Percent

Twenty-four Holstein calves were fed three experimental rations containing either 14% soybean meal, 20% rapeseed meal, or 20% formaldehyde-treated (0.7 g formaldehyde/100 g protein) rapeseed meal from 8 to 22 wk of age. No significant differences (P > 0.05) were observed in feed consumption, dry matter intake, liveweight gain, and feed conversion among the three groups. There was a significant (P < 0.05) reduction in rumen ammonia levels in calves receiving the treated rapeseed meal compared with the untreated rapeseed meal rations. Plasma urea levels and rumen fluid volatile fatty acids (mmol/100 ml and molar percent) did not differ significantly (P > 0.05) among treatments. There were no significant differences in the digestibilities of dry matter, nitrogen, acid detergent fiber, and gross energy among treatments, although treating the rapeseed meal with formaldehyde tended to reduce dry matter, nitrogen, fiber, and energy digestibility.

scholarly journals Nutritional implications of D-xylose in pigs

1991 ◽  
Vol 66 (1) ◽  
pp. 83-93 ◽  
Author(s):  
J. B. Schutte ◽  
J. de Jong ◽  
R. Polziehn ◽  
M. W. A. Verstegen
Keyword(s):  
Fatty Acids ◽  
Organic Matter ◽  
Small Intestine ◽  
Dry Matter ◽  
Volatile Fatty Acids ◽  
N Retention ◽  
Ileal Digestibility ◽  
Pentose Sugar ◽  
Gross Energy ◽  
Pentose Sugars

Hemicellulose consists primarily of pentose sugars, joined together in a polysaccharide chain with d-xylose as the most abundant component. Ileal digestibility and urinary excretion of d-xylose and associated effects of this pentose sugar on ileal and faecal digestibility of dry matter (DM), organic matter (OM), gross energy (GE) and nitrogen were studied in pigs. Castrated pigs were prepared with a post-valvular T-caecum cannula to measure ileal digestibility. Faecal digestibility was measured in non-cannulated pigs. d-xylose was given at dietary inclusion levels of 100 and 200 g/kg, and the control sugar, d-glucose, at a rate of 200 g/kg diet. Ileal digestibility of d-xylose as well as that of d-glucose was found to be close to 100%. The presence of d-xylose in the diet decreased ileal digesta pH and increased ileal flow of volatile fatty acids, suggesting the occurrence of microbial degradation of d-xylose in the pig small intestine. In pigs fed on the 100 g d-xylose/kg diet, 44.5% of the d-xylose intake appeared in the urine. This percentage increased significantly to 52.6 when pigs were fed on the 200 g d-xylose/kg diet. Ileal and faecal digestibility of DM, OM, GE and N, as well as N retention, decreased significantly in pigs fed on the 200 g d-xylose/kg diet.

scholarly journals Undernutrition in sheep. Nitrogen repletion by N-depleted sheep

1987 ◽  
Vol 57 (1) ◽  
pp. 77-88 ◽  
Author(s):  
F. D. DeB. Hovell ◽  
E. R. Ørskov ◽  
D. J. Kyle ◽  
N. A. MacLeod
Keyword(s):  
Volatile Fatty Acids ◽  
Live Weight ◽  
High Protein ◽  
N Losses ◽  
N Retention ◽  
Low Protein ◽  
A Value ◽  
The Difference ◽  
Protein Treatment ◽  
N Requirement

1. Wether lambs of 29–44 kg live-weight, totally nourished by the infusion of volatile fatty acids (VFA) into the rumen and casein into the abomasum, were given five treatments in consecutive periods. The treatments were (daily amounts per kg live weight (W)0.75): (a) high-protein for 7 d (2500 mg nitrogen, 650 kJ VFA); (b) low-protein for 7–15 d (525 mg N, 650 kJ VFA); (c) N-free for 7 d (no N, 450 kJ VFA); (d) very-low-protein for 24–28 d (300 mg N, 400 kJ VFA); (e) high-protein for 40 d (2500 mg N, 650 kJ VFA). Nine lambs were subjected to treatments (a), (b) and (c) (Expt 1) and four of the lambs additionally received treatments (d) and (e) (Expt 2).2. In Expt 1 all nine lambs had a positive N retention on treatment (a) but abrupt change to treatment (b) resulted in substantial negative N balances initially, and a period of approximately 5 d adaptation was required before N equilibrium was re-established. Animals again exhibited negative N balances when the N-free infusion (treatment c) was introduced and during that period there was no evidence of adaptation. Basal urinary N excretion was estimated to be 356 (SE 12) mg N/kg W0.75.3. In Expt 2 all four lambs were depleted of N when receiving the very-low-protein treatment (d). The progressively decreasing N losses recorded during days 1 to 12 of the treatment period were slightly greater than those recorded during days 13 to 28 but the difference between the means was not significant (P > 0.05). There was no evidence of an adaptation in N retention between days 13 and 28 of the treatment. As assessed during days 13 to 28 of the treatment the efficiency of utilization of infused casein N was 1.0; this compared with a value of 0.66 recorded during treatment (b) in Expt 1. Live weight loss during the period of N depletion was 101 (SE 27) g/d.4. When lambs were given treatment (e) during the last period of Expt 2, N repletion was rapid and complete within a few days. Ten days after the introduction of the treatment the rate of N retention was estimated to be 1019 (SE 38) mg/kg W0.75 per d and this value declined at a rate of 9.5 (SE 1.9) mg N/kg W0.76 per d for the following 30 d. In comparison, N retention determined for the high-protein treatment in Expt 1 was 724 (SE 66) mg N/kg W0.75 per d. Live-weight gains during N repletion were 292 (SE 26) g/d.5. It is concluded that N-depleted lambs can replete rapidly and that enhanced N accretion (compensatory growth) may persist for 4–5 weeks. If the improved efficiency of utilization of infused N observed during N depletion reflects a changed basal N requirement, the validity of simple factorial systems for estimating N requirement is called into question.

scholarly journals Effect of varying protein and energy intakes on nitrogen balance in Indian preschool children

1979 ◽  
Vol 42 (3) ◽  
pp. 417-423 ◽  
Author(s):  
A. K. Iyengar ◽  
B. S. Narasinga Rao ◽  
Vinodini Reddy
Keyword(s):  
Body Weight ◽  
Preschool Children ◽  
Energy Intake ◽  
Nitrogen Balance ◽  
Protein Intake ◽  
Energy Levels ◽  
Curvilinear Relationship ◽  
Protein Requirement ◽  
N Retention ◽  
Safe Level

1. The effect of varying protein intake at two energy levels of 334 and 418 KJ/kg body-weight was studied in four preschool children belonging to the low socio-economic group.2. Results indicated a curvilinear relationship between N intake and N retention. From this relationship, the protein requirement of the children at adequate energy intake was calculated.3. At adequate energy intake (418 KJ/kg body-weight) the protein requirement of the children was 1.33 g /kg. On decreasing the energy intake by 20% to 334 KJ /kg body-weight the protein requirement was found to be increased by 20% to 1.64 g/kg.4. Based on this study, a safe level of protein intake for Indian preschool children subsisting on a diet based predominantly on vegetable proteins has been suggested.

Response of urinary and plasma purine derivatives to various rates and infusion patterns of purines in sheep nourished by intragastric infusion

1997 ◽  
Vol 129 (3) ◽  
pp. 343-352 ◽  
Author(s):  
X. B. CHEN ◽  
T. FUJIHARA ◽  
K. NAKAMURA ◽  
P. O. MAWUENYEGAH ◽  
M. F. FRANKLIN ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Urinary Excretion ◽  
No Value ◽  
Volatile Fatty Acids ◽  
Estimated Glomerular Filtration Rate ◽  
Lag Time ◽  
Purine Derivatives ◽  
Entry Rate ◽  
Abomasal Infusion ◽  
Tubular Transport

The effects of exogenous purine supply on plasma concentration and urinary excretion of purine derivatives (PD), which include allantoin, uric acid, xanthine and hypoxanthine, were studied. Five sheep, totally nourished by intragastric infusion of volatile fatty acids and casein, were given an abomasal infusion of a mixture of adenosine and guanosine at three levels (5·0, 10·0 and 20·0 mmol/day) each in four infusion patterns (as one, two, or four 3-h infusion periods per day or infused continuously, P1 to P4 respectively). Urine was collected hourly over 24 h, and plasma samples were collected hourly for 7 h from the start of purine infusion. Both the plasma concentration of PD and its urinary excretion changed rapidly in response to the start and termination of purine infusion with a lag time of 2–3 h. Individual sheep differed considerably in the relative proportions of the different purine derivatives in the urine. The endogenous urinary PD excretion averaged 176 (±S.E. 28) μmol/kg W0·75 per day. Daily PD excretion in urine increased with the amount of purine infusion, but at each level the output decreased significantly in a gradient from P1 to P4. The response of total PD excretion (Y, mmol/day) to daily purine input (X, mmol/day) was predictable and followed the equation: Y=0·81 (±0·02)X+3·07(±0·81) × (u e−0·27X/u +1−u), where u is the duration over which the daily input was infused expressed as a proportion of 24 h. The recovery of the infused purines averaged 81%. When the infusion was given continuously, plasma PD concentration was relatively stable and was linearly correlated with the purine entry rate and daily PD excretion in the urine. The estimated glomerular filtration rate was 150 (±S.E. 16) litres/day and the estimated tubular transport maximum was 2·6 (±S.E. 1·3) mmol/day. It is concluded that due to the rapidity in the response of plasma and urinary PD to changes in the exogenous purine supply, spot measurements of PD in urine or plasma can be of no value for the estimation of exogenous purine uptake unless the purine supply is relatively constant throughout the day. Daily PD excretion in urine related to the exogenous purine uptake in a predictable and reproduceable manner and provides a reliable index for the estimation of the exogenous purine uptake.

Milk replacers containing isolated groundnut protein for preruminant lambs: the effect of protein concentration and energy intake on the requirement for lysine

1980 ◽  
Vol 31 (1) ◽  
pp. 133 ◽  
Author(s):  
DD Phillips ◽  
DM Walker
Keyword(s):  
Energy Intake ◽  
Nitrogen Balance ◽  
Protein Concentration ◽  
Sole Source ◽  
Energy Concentration ◽  
Energy Estimates ◽  
Plasma Urea ◽  
Protein Energy ◽  
Gross Energy ◽  
Milk Replacers

Preruminant male crossbred lambs, aged 2-5 days at the start of the experiment, were fed on milk replacers that contained groundnut protein isolate as the sole source of protein, supplemented with graded levels of L-lysine hydrochloride. A series of 6x 6 change-over designs with 4-day dietary periods was used in experiments 1 and 2, and a conventional 14-day nitrogen balance in experiment 3. Estimates were made of the minimum intake of lysine coincident with the maximum animal response (MIMR)-measured as maximum nitrogen balance (NB) or minimum plasma urea nitrogen (PUN) concentration. In experiment 1 three diets with different protein concentrations (0.11, 0.18 and 0.25 of total energy as protein) were compared at a controlled intake of gross energy (0.88 MJ/day per kg0.73). At each protein concentration the response to six graded levels of L-lysine hydrochloride was measured. In experiment 2 a diet of constant protein energy concentration (0.25) was offered at three different intakes of energy (0.63, 0.88 and 1.13 MJ/day per kg0 73). At each level of energy intake the response to six graded levels of L-lysine hydrochloride was measured. In experiment 3 a milk replacer containing 0.25 protein energy was offered at a constant intake of 0.88 MJ gross energy/day per kg0 73 and, as in the previous experiments, the response to SIX graded levels of L-lysine hydrochloride was measured. The MIMR for lysine (expressed as a percentage of dietary protein) decreased curvilinearly with an increase in protein concentration, but was unaffected by an increase in the intake of energy. Estimates based on PUN were similar to those based on NB, but the errors associated with the estimates were greater at the lowest protein concentration in experiment 1 and at the lowest intake of energy in experiment 2. Estimates of MIMR in experiments 1 and 3 were in close agreement.

Rearing dairy calves on irrigated tropical pastures. 1. Effect of protein level on liveweight gain and blood components

1992 ◽  
Vol 32 (5) ◽  
pp. 569 ◽  
Author(s):  
RJ Moss ◽  
RM Murray
Keyword(s):  
Energy Intake ◽  
Cottonseed Meal ◽  
Plasma Glucose ◽  
Volatile Fatty Acids ◽  
Ammonia Concentration ◽  
Wet Season ◽  
Tropical Pastures ◽  
Plasma Urea ◽  
Digestible Energy

Isoenergetic (12 MJ ME/kg DM) concentrate supplements of varying protein contents, were fed to dairy weaner calves grazing irrigated Setaria anceps cv. Kazungula pastures. Calves in each of the 5 treatment groups were given 1 kg concentratelday containing cracked maize and cottonseed meal in the proportions 1:0, 5:1, 4:2, 3:3 and 0:l. Acontrol group received no supplement. Two drafts of animals were used to measure the response during winter-spring (dry season) and summer (wet season). Without supplementation, calves gained 0.34 kg/day in spring and 0.20 kg/day during the wet season. Supplementation increased liveweight gains by 0.25 and 0.20 kg/calf.day in spring and summer, respectively. Substitution of cottonseed meal for maize did not consistently increase liveweight gain. Calves selected a pasture diet of 97% leaf, 16% crude protein and 66% in vitro dry matter digestibility (IVDMD). Mean daily rumen ammonia concentration was 134 mg NH3-N/L in unsupplemented calves, and 89 mg NH3-N/L in calves fed maize (P<0.05). Cottonseed meal was rapidly degraded in the rumen, with peak concentrations of rumen ammonia of 570 mg NH3-N/L 2 hours after feeding. Concentrations of rumen ammonia and plasma urea were closely correlated with supplemental protein intake (R2 = 0.98). Plasma total protein and albumin also increased with protein content of supplements (R2 = 0.73). Concentrations of plasma glucose and total volatile fatty acids in rumen liquor increased with supplementation, but were not influenced by the level of protein in the supplement. Correlations between liveweight gain and plasma glucose concentration were low (R2 = 0.65 spring; R2 = 0.20 summer). Digestible energy intake was the first limitation to liveweight gain of these calves grazing actively growing, tropical grass pastures. Although animals consistently selected leaf, the level of digestible energy intake was well below requirements, and increasing the level of protein in the diet was ineffective in increasing liveweight gain.

scholarly journals Nitrogen metabolism and urinary excretion of purines in goat kids

1989 ◽  
Vol 61 (2) ◽  
pp. 309-321 ◽  
Author(s):  
J. E. Lindberg
Keyword(s):  
Uric Acid ◽  
Urinary Excretion ◽  
Goat Milk ◽  
Live Weight ◽  
Experimental Period ◽  
Total N ◽  
N Retention ◽  
Period 2 ◽  
Gross Energy ◽  
Protein Supply

1. In Expt 1 three male goat kids of the Swedish Landrace breed were bottle-fed on isoenergetic liquid diets composed of goat's milk alone or substituted with 200, 400, 600 and 800 ml of a nitrogen-free liquid diet/1. The goat kids were 3 weeks old at the start of the experiment and weighed on average 5.3 (sd 0.22) kg. The experiment lasted for 45 d divided into nine 5 d periods. The goat kids were kept individually in metabolism cages, and faeces and urine were collected daily.2. In Expt 1 there was a significant (P < 0.001) relation between N intake and N retention, with an estimated (extrapolation) basal N excretion of 211 mg N/kg metabolic live weight (W0.75). While the creatinine excretion remained fairly constant (19.9 mg/W0.75), there was a tendency for both the allantoin and uric acid excretions to change with N intakes. Hypoxanthine showed no consistent excretion pattern, and xanthine could not be detected.3. In Expt 2 three male goat kids of the Swedish Landrace breed were used to study the effect of level of intake on N and purine metabolism. The first experimental period (period 1) started at 2 weeks of age (5.5 kg live weight) and the second experimental period (period 2) at 9 weeks of age (9.8 kg live weight). The goat kids were bottle-fed on goat milk at intended intakes of 400, 600, 800 and 1000 kJ gross energy/kg W0.75. Each treatment was given for 7 d with adaptation for 3 d and collections for 4 d.4. In Expt 2 there were significant (P < 0.001) increases in both live weight and N retention when level of intake was increased. With increasing N intakes both total N and urea-N excretions increased significantly (P < 0.05). The proportions of urea-N and ammonia-N were fairly constant within periods, and were on average respectively 0.81 and 0.059 in period I and 0.84 and 0.068 in period 2. There was no significant effect of treatment on the urinary excretion of allantoin, hypoxanthine, xanthine and creatinine. In period 2 uric acid excretion was significantly (P < 0.01) affected by the treatments.5. From the presented findings it is concluded that the endogenous urinary excretion of purine derivatives in a young growing ruminant was only marginally affected by large variations in protein supply, and also by the level of intake of milk.

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