Phosphorus metabolism in ruminants. 1. Techniques for phosphorus depletion

1985 ◽  
Vol 36 (4) ◽  
pp. 637 ◽  
Author(s):  
JH Ternouth ◽  
HMS Davies ◽  
JTB Milton ◽  
MW Simpson-Morgan ◽  
NE Sands
Keyword(s):  
Artificial Saliva ◽  
Extracellular Fluid ◽  
Inorganic Phosphorus ◽  
Phosphorus Metabolism ◽  
Parotid Saliva ◽  
Parotid Duct ◽  
Low Phosphorus ◽  
Replacement Technique ◽  
Phosphorus Depletion

A dietary technique and a parotid saliva replacement technique for depleting ruminants of phosphorus are described. The unilateral parotid depletion technique, involving permanent re-entrant parotid duct catheterization, with phosphorus-free artificial saliva returned to the duct, rapidly depressed blood and ruminal inorganic phosphorus concentrations of animals fed on a low-phosphorus diet. The parotid technique is capable of removing the total extracellular fluid inorganic phosphorus of cattle, goats and sheep in 5-14 h and is of value for creating acute phosphorus deficiencies in adult ruminants. Removal of phosphorus from the ruminant is slower with the dietary technique.

Phosphorus metabolism in ruminants. 2. Effects of inorganic phosphorus concentration upon food intake and digestibility

1985 ◽  
Vol 36 (4) ◽  
pp. 647 ◽  
Author(s):  
JTB Milton ◽  
JH Ternouth
Keyword(s):  
Organic Matter ◽  
Food Intake ◽  
Phosphorus Deficiency ◽  
Inorganic Phosphorus ◽  
Phosphorus Concentration ◽  
Parotid Saliva ◽  
Ruminal Fluid ◽  
Saliva Secretion ◽  
Parotid Duct ◽  
High Calcium

Four sheep, prepared with bilateral re-entrant parotid duct catheters, ruminal fistulas and abomasal catheters, were offered a pelleted high-calcium low-phosphorus diet. By infusing saline or phosphate solutions into the abomasum with or without diversion of the parotid saliva, three treatments were created: low ruminal, low blood; high ruminal, high blood; and low ruminal, high blood inorganic phosphorus concentrations. The organic matter intake of the sheep on the low-blood treatment was 34% less than on either of the high-blood treatments. Although there were no differences between treatments in organic matter digestibility, the digestibility of the neutral-detergent fibre fraction on both low-ruminal treatments was 5% lower than on the high-ruminal treatment. There were no differences between treatments in ruminal fluid volume, but there was a tendency for the retention times of ruminal fluid and caeco-colic digesta to be greater and the rate of flow of fluid from the rumen and daily parotid saliva secretion to be lower when less food was eaten. It is concluded that although phosphorus deficiency may depress microbial digestion, the reduced food intake of the sheep was not due to a depression in microbial digestion and that the primary factor limiting food intake was due to some nondigestive tract disturbance, possibly a disturbance of intracellular metabolism.

scholarly journals Effects of pre-incubation in sheep and goat saliva on in vitro rumen digestion of tanniferous browse foliage

2013 ◽  
Vol 151 (6) ◽  
pp. 898-906
Author(s):  
H. AMMAR ◽  
R. BODAS ◽  
J. S. GONZÁLEZ ◽  
A. Z. M. SALEM ◽  
F. J. GIRÁLDEZ ◽  
...  
Keyword(s):  
Rumen Fluid ◽  
Artificial Saliva ◽  
Rumen Fermentation ◽  
Gas Production ◽  
Parotid Saliva ◽  
Rosa Canina ◽  
Fermentation Kinetics ◽  
Alfalfa Hay ◽  
Parotid Duct

SUMMARYA two-stage in vitro procedure was used for assessing the activity of parotid saliva to enhance rumen digestion of tanniniferous browse foliage. The procedure consisted of pre-incubation in saliva for 4 h at 39 °C followed by incubation in diluted buffered rumen fluid. Using this procedure, a study was conducted to examine the effects of pre-incubation in sheep (SS), quebracho-supplemented sheep (qSS) and goat (GS) parotid saliva or in McDougall's artificial saliva (AS, used as control) on in vitro rumen fermentation kinetics (estimated using the gas production technique) of browse foliage from six shrub species (Cytisus scoparius, Genista florida, Rosa canina, Quercus pyrenaica, Cistus laurifolius and Erica australis) collected over two seasons (spring and autumn), thus varying the in vitro digestibility (from 0·597 to 0·903) and tannin contents (from 3 to 130 g tannic acid equivalent/kg dry matter (DM)). Saliva was collected from four sheep and four goats fed alfalfa hay, and from four sheep fed the same alfalfa hay but supplemented with quebracho (rich in condensed tannins) for 60 d, through a cannula inserted in the parotid duct, and rumen fluid was always from sheep fed alfalfa hay. The extent of degradation when browse foliage was pre-incubated in qSS was similar to that observed with control AS (0·449 v. 0·452, respectively), and 8% less than the value with pre-incubation in SS (0·490). In vitro fermentation kinetics (gas production parameters) of browse foliage were not significantly enhanced with pre-incubation in qSS compared with SS, whereas in vitro digestibility and extent of degradation in the rumen were significantly reduced with qSS compared with SS. After pre-incubation in sheep and goat saliva, the extent of browse foliage degradation was significantly increased by 4–8% compared with pre-incubation in the control AS. Fermentation efficiency of browse foliage was increased (P<0·05) with pre-incubation in GS compared with SS. Sheep or goat saliva may have some activity to affect in vitro rumen fermentation of the foliage samples incubated, enhancing extent of degradation of tannin-rich browse. However, a relationship between the magnitude of this effect and the tannin content of the browse foliage could not be established, suggesting that sheep and goat saliva may not be particularly important in neutralizing tannins.

ACCLIMATIZATION TO COLD: OBSERVATIONS ON THE MECHANISM OF THE REDUCED IMMEDIATE ADRENAL RESPONSE

1959 ◽  
Vol 37 (1) ◽  
pp. 671-677
Author(s):  
Doris Nicholls ◽  
Rosemary Molloy ◽  
Kathleen Stavraky ◽  
R. J. Rossiter
Keyword(s):  
Adrenal Gland ◽  
Peripheral Nerve ◽  
Cold Stress ◽  
Cold Exposure ◽  
Inorganic Phosphorus ◽  
Phosphorus Metabolism ◽  
Adrenal Tissue ◽  
Adrenal Response

The incorporation of inorganic phosphorus labelled with P32 into the inorganic phosphorus of the adrenal gland was measured in rats acclimatized to cold for 4 weeks. Previously it was reported that the immediate pituitary–adrenal response to brief cold exposure (2 hours at −5 °C), as judged by the increased P32 incorporation is considerably decreased in rats that have been acclimatized. Some observations are now reported on the mechanism of this reduced immediate response.The administration of ACTH, pitressin, or adrenaline caused similar increases in the adrenal phosphorus metabolism in acclimatized and non-acclimatized control rats. Acclimatization could still be demonstrated in rats after the fur had been removed by clipping.From these results it is concluded that the decreased immediate pituitary–adrenal response to an exposure to more severe cold, observed in acclimatized rats, is not the result of an increased fur thickness, nor is it the result of a decreased sensitivity of the adrenal tissue to ACTH, or to a decreased sensitivity of the pituitary or hypothalamus to a given stimulus. It is suggested that the reduction in the immediate pituitary–adrenal response to a more severe cold stress in acclimatized rats might be due to an alteration in the sensitivity of the peripheral nerve receptors, or in the mechanism, nervous or otherwise, whereby the pituitary is stimulated.

PHOSPHORUS METABOLISM OF THE ADRENAL GLAND: THE MECHANISM OF THE CHANGE AFTER HYPOPHYSECTOMY

1954 ◽  
Vol 32 (3) ◽  
pp. 261-270 ◽  
Author(s):  
B. E. Riedel ◽  
R. J. Rossiter
Keyword(s):  
Adrenal Gland ◽  
Specific Activity ◽  
Extracellular Fluid ◽  
Phosphorus Metabolism ◽  
Time Intervals ◽  
Inorganic P ◽  
Fluid Compartment ◽  
Hypophysectomized Rats ◽  
Specific Activities ◽  
Isotope Equilibrium

The specific activity of the intracellular inorganic phosphate (P) of the adrenal gland relative to that of the inorganic P of the plasma is significantly decreased in hypophysectomized rats at time intervals as long as 16 hr. after the injection of inorganic P labelled with P32. The specific activity of the intracellular inorganic P was determined (1) by measuring the specific activity of the easily-hydrolyzable acid-soluble P, which rapidly comes into isotope equilibrium with the intracellular inorganic P, (2) by calculation, from the specific activity of the inorganic P of the whole adrenal, assuming values for the specific activity and the concentration of the inorganic P of the extracellular fluid and the volume of the extracellular fluid compartment, and (3) by measuring the specific activities of the inorganic P of both the adrenal gland and the plasma at a series of time intervals after the injection of the P32. It is concluded that the decrease in the relative specific activity of the intracellular inorganic P of the adrenal is the result of a slowing in the passage of inorganic P32 across the cell membrane, i.e. from the extracellular to the intracellular fluid.

Studies of the skeleton of the sheep. III. The relationship between phosphorous intake and resorption and repair of the skeleton in pregnancy and lactation

1959 ◽  
Vol 52 (1) ◽  
pp. 1-12 ◽  
Author(s):  
D. Benzie ◽  
A. W. Boyne ◽  
A. C. Dalgarno ◽  
J. Duckworth ◽  
R. Hill
Keyword(s):  
Cervical Vertebrae ◽  
Inorganic Phosphorus ◽  
Ash Content ◽  
Long Bones ◽  
Daily Ration ◽  
Low Phosphorus ◽  
Pregnancy And Lactation ◽  
The Relationship ◽  
Phosphorus Intake ◽  
In Pregnancy

1. The ash content of the skeleton of Cheviot ewes fed a daily ration containing about 4·5 g. of phosphorus fell by 18·8% between mid-gestation and mid-lactation, and 2 months after the end of lactation the loss was fully replaced.2. In ewes fed a daily ration containing about 1·5 g. of phosphorus the loss of skeletal ash was 39·9% at mid-lactation, and this was not replaced 2 months after the end of lactation. When the phosphorus intake was raised in mid-lactation from 1·5 to 4·5 g. repair was greater but was still not complete.3. Resorption was greater in bones rich in cancellous tissue, such as the cervical vertebrae, than in those rich in compact tissue, such as the shafts of long bones, but when severe resorption took place significant losses were found in the shafts of long bones as well as in other bones.4. Whole blood inorganic phosphorus values were very low, particularly during lactation, in ewes fed on the low-phosphorus ration. When extra phosphorus was fed from mid-lactation onwards blood phosphorus values rose to normal in less than four weeks, a much more rapid recovery than that which took place in the skeleton.5. Resorption of the skeletons of ewes on both moderate and low-phosphorus rations could be detected using radiographs taken of the radius in the living animal at mid-lactation, and severe resorption found in ewes fed on the low-phosphorus ration could be distinguished readily from the milder resorption found in ewes fed on the moderate-phosphorus ration.

Effects of induced, subclinical phosphorus deficiency on feed intake and growth of beef heifers

1982 ◽  
Vol 98 (1) ◽  
pp. 23-29 ◽  
Author(s):  
B. J. W. Gartner ◽  
G. M. Murphy ◽  
W. A. Hoey
Keyword(s):  
Cell Wall ◽  
Weight Gain ◽  
Feed Intake ◽  
Crude Protein ◽  
Phosphorus Deficiency ◽  
Protein Digestibility ◽  
Inorganic Phosphorus ◽  
Feed Conversion ◽  
Beef Heifers ◽  
Low Phosphorus

SUMMARYHereford heifers were fed a diet (7·0 MJ ME/kg D.M.) containing 0·09 % phosphorus but complete with regard to other nutrient constituents. Only after 19 weeks wore the effects of subclinical aphosphorosis evident in the form of reduction in feed intake, cessation of weight gain, increased feed conversion and decreases in tho concentration of inorganic phosphorus in blood and saliva. Heifers supplemented daily with 12 g phosphorus sustained a weight gain of about 0–2 kg/day over 62 weeks as did other supplemented heifers whose feed intake was restricted to that of tho low phosphorus treatment. The effects of phosphorus supplementation were thus demonstrated without being confounded by concomitant increases in feed intake.Phosphorus supplementation resulted in significantly lowered apparent crude protein digestibility and a slight increaso in cell wall digestibility.

PHOSPHATE EXCRETION AND PARATHYROID FUNCTION IN THYROTOXICOSIS

1964 ◽  
Vol 28 (3) ◽  
pp. 281-288 ◽  
Author(s):  
R. McG. HARDEN ◽  
M. T. HARRISON ◽  
W. D. ALEXANDER ◽  
B. E. C. NORDIN
Keyword(s):  
Inorganic Phosphorus ◽  
Plasma Calcium ◽  
Phosphorus Metabolism ◽  
Phosphate Excretion ◽  
Parathyroid Function ◽  
Calcium And Phosphorus ◽  
High Phosphate

SUMMARY Certain aspects of calcium and phosphorus metabolism have been studied in thirty-six patients with thyrotoxicosis. The plasma calcium and inorganic phosphorus concentrations were not significantly different from normal. The basal phosphate excretion index was low (− 0·08 ± 0·01) and there was an impaired response to high phosphate feeding. These findings suggest that parathyroid function is reduced in thyrotoxicosis.

Secretion and absorption of phosphorus in the gastrointestinal tract of sheep fed on four diets

1979 ◽  
Vol 30 (3) ◽  
pp. 503 ◽  
Author(s):  
DP Poppi ◽  
JH Ternouth
Keyword(s):  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Relative Concentration ◽  
The Other ◽  
Phosphorus Metabolism ◽  
Meat And Bone Meal ◽  
Bone Meal ◽  
Low Phosphorus ◽  
High Degree ◽  
Phosphorus Intake

The effects of three phosphorus supplements on the metabolism of phosphorus in the gastrointestinal tract of sheep were examined. One group of sheep was fed on a low phosphorus (P-L) diet and three other groups on diets supplemented with monosodium orthophosphate (P-MSOP), meat and bone meal (P-MBM) or bran (P-ORG). The total phosphorus (TP), ultrafilterable phosphorus (UP) and nucleic acid phosphorus (NP) in the digesta were measured. There was a large net secretion of phosphorus into the rumen and the first quarter of the small intestine, and net absorption from the remainder of the small intestine of all sheep. The relative concentration of phosphorus in the omasum suggested considerable omasal secretion and a subsequent abomasal absorption of phosphorus, but this was considered to be largely an artefact. There were no consistent differences between diets in the net secretion and absorption of TP at sites along the gastrointestinal tract. Sheep fed on the P-L diet secreted more phosphorus per unit of phosphorus intake than sheep on the other diets. Most UP was present in the abomasum and cranial small intestine where the pH was lowest. The concentration of UP fell precipitously in the small intestine, which suggested that this was the major form of phosphorus absorbed and that there was a high degree of complex formation at the higher pH. The concentration of NP was relatively constant, and the lowest NP/TP ratios were found in the cranial small intestine. NP formed in the rumen was mainly degraded in the cranial small intestine. NP represented half the TP in the colon of sheep fed on diet P-L. The results indicate that the form of phosphorus supplement did not influence phosphorus metabolism in the gastrointestinal tract.

The Origin and Fate of Salivary Urea and Ammonia in Man

1977 ◽  
Vol 52 (1) ◽  
pp. 9-17 ◽  
Author(s):  
J. Kopstein ◽  
O. M. Wrong
Keyword(s):  
Plasma Concentration ◽  
Nitrogen Concentration ◽  
Urea Concentration ◽  
Ionic Diffusion ◽  
Parotid Saliva ◽  
Urea Nitrogen ◽  
Plasma Urea ◽  
Parotid Duct ◽  
Hydrolysis Of ◽  
Hydrolysis Of Urea

1. Saliva obtained from the parotid duct of normal and uraemic subjects had an average urea concentration of 86% of the plasma concentration whereas in mixed saliva obtained from the mouth the urea concentration was only 31% of the plasma concentration. Ammonia concentrations were low or unmeasurable in parotid saliva but varied between 0·6 and 26 mmol/kg in oral saliva, showing a positive correlation with the plasma urea concentration. 2. The urea in samples of mixed oral saliva incubated at 37°C disappeared by 290 min. Ammonia steadily increased during incubation; within the first 100 min, the increase could be largely accounted for by bacterial hydrolysis of urea, but later non-urea sources became relatively more important. 3. These findings suggest that the ammonia in mixed oral saliva is derived by bacterial hydrolysis of urea within the mouth. However, the concentration of ammonia plus urea nitrogen in oral saliva was only 76% of the urea nitrogen concentration of parotid saliva, which suggests that some ammonia is lost from the mouth by buccal absorption or by volatilization. 4. To assess the role of non-ionic diffusion of ammonia through the buccal mucosa, we studied the effect of pH on the disappearance of ammonia from buffered solutions retained in the mouth. Ammonia concentrations fell more rapidly at pH 9 than at pH 7, as also did those of hydrazine, a non-volatile analogue of ammonia which is known to be absorbed through other mucosae by non-ionic diffusion. These findings suggest that salivary ammonia is reabsorbed passively through the oral mucosa in the un-ionized phase.

scholarly journals Effect of different levels of phosphorus on rumen microbial fermentation and synthesis determined using a continuous culture technique

1987 ◽  
Vol 57 (2) ◽  
pp. 279-290 ◽  
Author(s):  
Sylvie Komisarczuk ◽  
R. J. Merry ◽  
A. B. McAllan
Keyword(s):  
Continuous Culture ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Artificial Saliva ◽  
Inorganic Phosphorus ◽  
Ammonia Nitrogen ◽  
Culture Technique ◽  
Phosphorus Requirements ◽  
Micro Organisms

1. A continuous culture technique was used to study the phosphorus requirements of rumen micro-organisms. Solutions of artificial saliva containing 120, 80, 40 and 0 mg inorganic phosphorus (Pi)/1 were infused into the reaction vessels previously inoculated with rumen contents, resulting in Piconcentrations in the vessel contents of 48, 28, 4 and < 1 mg/l respectively. Various fermentative and synthetic characteristics were examined.2. In the vessel contents, concentrations of protozoa (about 0.9 x 105/ml) were not significantly affected by piconcentration. Total volatile fatty acids (VFA) produced averaged about 6.83 mmol/h with Pilevels of 48 and 28 mg/l. Reduction in Piconcentrations to 4 and < 1 mg/l resulted in significant reductions in total VFA to approximately 6.25 and 3.75 mmol/h respectively, accompanied by a rise in pH from 6.5 to 7.3. Ammonia-nitrogen values, which averaged about 131 mg/l at the higher Piconcentrations, also increased with the lowest level of Pito about 240 mg/l. ATP concentrations averaged about 14 μmol/l at the highest Piconcentration and fell progressively with each reduction in Piconcentration to a final value of 2.5μmol/1 with the Pilevel < 1 mg/1.3. At Piconcentrations of 48 and 28 mg/l, the digestibilities of xylose, arabinose and cellulose-glucose were maintained at about 0.90, 0.62 and 0.70 g/g input respectively. At lower Pi, concentrations these digestibilities fell significantly and corresponding values at Pi< 1 mg/l were 0.73, 0.41 and 0.31 respectively. Starch digestion was unaffected by Piconcentrations and remained at about 0.90 g/g input.4. The amount of microbial-N synthesized averaged 0.48 g/d and was maintained with Piconcentrations down to 4 mg/l. There was, however, a significant reduction to 0.26 g/d with Piconcentrations of < l mg/l. The effiency of microbial protein synthesis was variable but averaged approximately 25 g N/kg total carbothdrate fermented.5. It was estimated that the minimum Piconcentrations required in rumen fluid in vivo to maintain maximum degradative and synthetic microbial activities was in the range 75–100 mg/l and that the over-all P requirement of the microbes was of the order of 5.1 g/kg apparently digested organic matter intake.

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