The effect and site of action of potassium upon magnesium absorption in sheep

1976 ◽  
Vol 27 (6) ◽  
pp. 873 ◽  
Author(s):  
FM Tomas ◽  
BJ Potter

The effect of potassium chloride infusion to the rumen or duodenum of sheep upon the absorption of magnesium from the stomach and intestinal regions has been examined. Three Merino ewes, each prepared with a cannula into the rumen and a re-entrant cannula into the duodenum, were offered a basal diet (control) which provided 46.3–51.1 mmoles magnesium and 299–320 mmoles potassium per day. Potassium chloride (500–800 mmoles/day) was infused continuously to either the rumen or duodenum. Digesta fluid flows were estimated from the dilution of a Cr-EDTA solution continuously infused to the rumen. Potassium infusion to either gastrointestinal site led to a comparable increase in the water intake, urine volume and levels of plasma and urinary potassium. Infusion to the rumen caused a marked increase in the potassium levels and a decrease in sodium levels in rumen fluid, as well as an increase in the rumen fluid to blood bioelectrical potential. No effect of treatment on digesta fluid flows was observed. Net magnesium absorption was lowered only when potassium was infused to the rumen, and the reduction was almost entirely due to reduced absorption of magnesium from the stomach. There was no consistent effect on absorption of magnesium from the intestines. Plasma magnesium levels were lowered by both the intraruminal infusion and, to a lesser extent, the duodenal infusion of potassium. The results indicate that although one consequence of potassium ingestion by sheep may be an enhancement of the urinary excretion of magnesium, the major effect on magnesium metabolism is a substantial reduction of absorption of magnesium from the reticulorumen.

1971 ◽  
Vol 51 (1) ◽  
pp. 179-186 ◽  
Author(s):  
E. E. LISTER ◽  
W. SZEPESI ◽  
K. A. WINTER ◽  
H. F. JEFFERS ◽  
V. S. LOGAN

Prepasture feeding of low quality hay versus hay and grain had no subsequent effect on rumen fluid ammonia, blood urea, or plasma calcium, glucose and lactic acid concentration in steers turned out on lush pasture. Steers previously fed hay and grain had lower plasma magnesium levels on the first day on unsupplemented pasture than those fed hay prior to pasture. Supplemental feed on pasture partly alleviated the depression in plasma magnesium on the first day on pasture. Feeding supplemental hay with pasture tended to lower rumen fluid ammonia, blood urea and plasma lactic acid compared with feeding no supplement during the initial days on pasture, indicating the desirability of hay feeding during this time. A hay and grain supplement with pasture had a similar effect to the hay supplement on rumen-fluid ammonia, and plasma lactic acid, but a lesser effect on blood urea concentration. Neither supplemental hay nor hay plus grain affected plasma calcium or glucose levels. All steers showed an increase in rumen fluid ammonia, blood urea and plasma lactic acid on the first day and a decrease in plasma calcium and magnesium on the second day on pasture. Blood urea, plasma magnesium and plasma calcium concentrations had not returned to prepasture levels by 21 days on pasture.


Author(s):  
Siska Siska ◽  
Franciscus D. Suyatna ◽  
Abdul Mun'im ◽  
Anton Bahtiar

Based on previous reports, the combination of captopril and celery could reduce blood pressure in hypertensive patients. This study aimed to investigate the changes of blood pressure, urine volume, sodium, and potassium level, due to concomitant administration of captopril with celery extract orally in male rats induced by 4% NaCl. The blood pressure was measured using a non-invasive tail method. The urine and blood were collected, and the sodium, potassium concentration, and cumulative urine volume were measured. The combination of 5 mg/kgBW of captopril and 40 mg/kgBW of celery extract decreased the blood pressure in hypertensive rats better than 5 mg/kgBW of captopril alone. The fell in blood pressure was followed by an increase in urine volume. Urinary and serum sodium, serum potassium levels tended to increase in all treatment groups, but not significantly different from the healthy group. Urinary potassium levels tended to decrease except in the combined 5 mg/kgBW of captopril and 40 mg/kgBW of celery extract. In conclusion, oral administration of a combination of 5 mg/kgBW captopril and 40 mg/kgBW celery extract decreased the blood pressure to the standard value in NaCl-induced hypertension rats.Keywords: Apium graveolens, captopril, celery, hypertension, pharmacodynamic


2010 ◽  
Vol 55 (No. 7) ◽  
pp. 276-285 ◽  
Author(s):  
T.J. Guo ◽  
J.Q. Wang ◽  
D.P. Bu ◽  
K.L. Liu ◽  
J.P. Wang ◽  
...  

The objective of the present study was to investigate the effects of virginiamycin (VM ) supplementation on ruminal fermentation and microbial populations in steers. Four ruminally cannulated Chinese Luxi steers (BW 559.4 ± 30.1 kg) were used in a crossover design experiment with an experimental period of 28 days. The forage to concentrate ratio of the basal diet was 35:65 on dry matter basis. The experiment consisted of control treatment and treatment with control diet plus VM at a dose of 30 mg/kg concentrate (DM basis). Rumen fluid was collected at 07:30 prefeeding, at 11:30 and 17:30 postfeeding on day 27 and 28. A part of the pooled sample from rumen fluid was transferred to anaerobic culture by a roll-tube technique and analysed for species-specific real-time PCR quantification. The remaining pooled rumen fluid sample was analyzed for pH, VFA, ammonia N and l-lactic acid. The results showed that VM increased the ruminal pH (6.70 vs. 6.63; P < 0.05), but it decreased ammonia nitrogen (4.94 vs. 6.19 mg/100 ml; P < 0.01) and mean counts of amylolytic bacteria and proteolytic bacteria (P < 0.01) as compared to the control. The additive VM did not affect the l-lactic acid concentration (1.39 vs. 1.26 mmol/l) in rumen fluid. Compared to the control, the steers receiving VM have altered a trend of quantification of Selenomonas ruminantium, Anaerovibrio lipolytica, Ruminococcus albus and Streptococcus bovis in rumen fluid (0.05<p<0.1) as compared to the control. However, VM had no significant effect on Lactobacillus spp. (P = 0.41), Butyrivibrio fibrisolvens (P = 0.35), on the genus Ruminococcus (P = 0.25), Ruminococcus flavefaciens (P = 0.52), Prevotella ruminicola (P = 0.54), on the genus Prevotella (P = 0.67) and Megasphaera elsdenii (P = 0.97). In this study, we found that VM had selective effects on ruminal bacteria and influenced ruminal fermentation by changing a part of the specific ruminal bacteria populations.


1998 ◽  
Vol 130 (2) ◽  
pp. 199-204 ◽  
Author(s):  
H. PEIRIS ◽  
R. ELLIOTT ◽  
B. W. NORTON

Sorghum grain was included in a basal diet of molasses (molasses 505, urea 21, sunflower meal 191, pangola grass hay 250, minerals 31 g/kg as fed) at rates of 0, 202, 391 and 707 g/kg, generating diets in which grain replaced 0 (diet A), 33 (diet B), 66 (diet C) and 100% (diet D) of the molasses and hay. The four diets were fed to groups of four Hereford steers (293–334 kg liveweight) over a 96-day period. One half of each treatment group was implanted with a growth promotant (zeranol), and all were slaughtered at a commercial abattoir at the end of the trial. The inclusion of 33% grain increased voluntary feed consumption, digestible dry matter (DM) intake (from 57·6 to 82·0 g digestible DM/kg0·75 per day and significantly increased liveweight gain from 592 to 900 g/day. Zeranol implantation also increased liveweight gain but not feed intake. Steers given only grain (diet D) had the highest liveweight gains (1127 g/day). The addition of grain to molasses diets decreased urinary N excretion and increased ammonia and volatile fatty acid (VFA) concentrations in rumen fluid. Molar proportions of propionic acid in total VFA increased from 0·15 to 0·20, and butyric acid decreased from 0·36 to 0·29 when 33% of the molasses was replaced by sorghum grain. The fat content (depth at sacral position) of the carcasses of steers given grain only (diet D) was significantly greater (14 mm) than that of steers given the basal diet of molasses (4 mm), and carcass fat contents were intermediate (10 and 11 mm) for steers given diets B and C respectively. It was concluded that the inclusion of small amounts of grain in molasses-based diets increased cattle growth principally by increasing digestible energy intake without decreasing molasses intake, thus improving the efficiency of utilization of molasses in molasses-based diets.


1987 ◽  
Vol 67 (4) ◽  
pp. 1083-1091 ◽  
Author(s):  
L. R. NDLOVU ◽  
J. G. BUCHANAN-SMITH

Nine lambs fitted with rumen cannulae were used in two 5 × 5 Latin squares to measure the effect of alfalfa hay, C4- and C5-branched- and straight-chain volatile fatty acids (C4/C5 VFAs), cell wall from alfalfa hay (ALFCW) and a soybean protein preparation on intake and rumen digestion of a basal corncob diet with urea included at 30 g kg−1. Relative to the control, alfalfa hay decreased (P < 0.05) intake of the basal diet but increased (P < 0.05) total dry matter intake. ALFCW and soybean protein did not affect intake of the basal diet and total dry matter (P > 0.05). C4/C5 VFAs increased intake of basal diet by sheep in one square (P < 0.05) but had no effect (P > 0.05) on intake with sheep in the other square. Alfalfa hay, ALFCW and soybean protein increased (P < 0.05) total VFA concentration in rumen fluid while only alfalfa hay and C4/C5 VFAs consistently increased isobutyrate, isovalerate and valerate levels in rumen fluid (P < 0.05). In comparison with the control diet, soybean protein elevated (P < 0.05) mean rumen ammonia-N levels whereas C4/C5 VFAs depressed them; however, values exceeded 17 mg dL−1 rumen fluid on all treatments. Most measures of digestion kinetics of fiber from corncobs were unaffected by supplementation (P > 0.05). Alfalfa hay and ALFCW increased (P < 0.05) rate of passage of digesta from the reticulo-rumen. It was concluded that alfalfa hay has a reduced role in improving intake of corncob diets when there is also sufficient NPN in the diet. Key words: Roughage (poor quality), volatile fatty acids, rumen ammonia levels, chromium-mordanted cell walls


Author(s):  
C.J. Newbold ◽  
R.J. Wallace ◽  
I.M. Nevison

A wide range of compounds has been described which have the potential to improve animal production by manipulating the rumen fermentation. Prominent among these rumen modifiers are the ionophores. Ionophores, such as monensin and tetronasin, improve feed efficiency, partly by increasing the flow of amino-N from the rumen and partly by stimulating the production of propionate in the rumen with an associated reduction in the production of methane (Russell and Strobel, 1988). Recently there has been increasing interest in the use of yeast culture (YC) and other fungal preparation to modify the rumen fermentation. These products have been shown to increase bacterial numbers within the rumen with an associated increase in the breakdown of fibre and supply of microbial protein (Williams and Newbold, 1990). YC has also been reported to increase the production of propionate in the rumen. Little appears to be known about the effect a combination YC and an ionophore would have on the rumen fermentation. This study describes the effects of the ionophores monensin and tetronasin on the fermentation of hay by rumen fluid from sheep fed a basal diet with or without YC.


2004 ◽  
Vol 71 (3) ◽  
pp. 297-303 ◽  
Author(s):  
Surasak Jittakhot ◽  
J Thomas Schonewille ◽  
Hugo Wouterse ◽  
Anton WJ Uijttewaal ◽  
Chalermpon Yuangklang ◽  
...  

Earlier studies with temporarily isolated rumen of heifers show saturation kinetics of Mg efflux across the rumen wall. Therefore, we hypothesized that high Mg intakes would not further increase the rate of Mg absorption in cows. To test our hypothesis, six ruminally fistulated non-pregnant dry cows were given diets with different Mg concentrations in a 6×6 Latin square design. Desired concentrations of Mg were attained by adding MgO to the basal diet and the Mg concentrations in the total rations were 3·8, 6·4, 9·1, 11·8, 14·1 and 17·3 g Mg/kg dry matter, which provided Mg intakes of 27·1, 44·6, 64·6, 83·5, 100·4 and 124·3 g/d, respectively. Increasing Mg intakes were associated with increased (P<0·001) faecal Mg excretion. However, apparent Mg absorption expressed as g/d was not significantly different for Mg intakes from 100·4 to 124·3 g/d while Mg absorption expressed as a proportion of intake was not significantly different for Mg intakes ranging from 64·6 to 124·3 g/d. Mg concentrations in rumen fluid after feeding increased (P<0·001) with increasing Mg intakes. Apparent absorption of Mg appeared to become saturated at a ruminal Mg concentration of 17·5 mM (Mg intake of 83·5 g/d). Group-mean post-feeding concentrations of Mg and Na in rumen fluid were significantly correlated (Pearson's r=−0·96; P=0·003, n=6). This study showed that under conditions of practical dairy cow feeding, Mg absorption was maximal at Mg intakes [ges ]84 g/d.


1976 ◽  
Vol 27 (3) ◽  
pp. 437 ◽  
Author(s):  
FM Tomas ◽  
BJ Potter

The effect of magnesium chloride infusion to different sites in the gastrointestinal tract of sheep upon the net absorption of magnesium from different regions of the digestive tract has been examined. Four Merino wethers were each prepared with cannulas sited in the rumen, in the duodenum adjacent to the pylorus and in the terminal ileum. The basal diet provided 18.45 mmoles magnesium/ day and an additional 65 mmoles magnesium/day as magnesium chloride was continuously infused into (A) the rumen, (B) the rumen and duodenum in equal portions, (C) the duodenum and (D) the terminal ileuni. A continuous infusion of Cr-EDTA to the ruinen enabled digcsta and magnesium flow rates to be estimated from digesta samples obtained from the intestinal cannulas at 4 hr intervals over 3 days. For treatments A, B, C and D respectively, the mean net absorption of magnesium (mmoles/day) from the rumen was 20.4, 11.4, 1.4 and 3.4; from the small intestine –0.5, 1.7, –5.1 and –9.8; from the large intestine 4.6, 2.2, 12.7 and 12.3; and from the total gastrointestinal tract 24.6, 15.4, 9.1 and 4.9. In each case the effect of treatment was significant. The total net absorption of magnesium caudal to the pylorus was unaffected by treatment. Plasma magnesium levels were reduced during post-ruminal infusion of magnesium, but these changes were not obviously linked to the changed net absorption from the intestinal segments. The urinary and faecal excretion of magnesium, but not the magnesium balance, was strongly related to the total net absorption of magnesium. The results emphasize the major contribution of the stomach to the gastrointestinal net absorption of magnesium and show that although the amount absorbed from this region may influence separately the net absorption from the large and small intestine, it does not appear to influence the overall intestinal net absorption of magnesium.


1989 ◽  
Vol 77 (1) ◽  
pp. 105-111 ◽  
Author(s):  
M. G. Koopman ◽  
G. C. M. Koomen ◽  
R. T. Krediet ◽  
E. A. M. de Moor ◽  
F. J. Hoek ◽  
...  

1. In a group of 11 normal individuals we measured glomerular filtration rate (GFR) by inulin clearances and effective renal plasma flow (ERPF) by p-aminohippurate clearances during a period of 24 h and a regimen of bedrest, identical food intake per 3 h and normal sleep/wake and light/dark cycles. 2. All subjects had a circadian rhythm for GFR with a maximum of 122 ml/min (sd 22) in the daytime, a minimum of 86 ml/min (sd 12) at night and with a relative amplitude of 33% (sd 15). 3. ERPF had a circadian rhythm with a similar relative amplitude as the GFR rhythm, but with a different phase. Because of this difference in phase, the calculated filtration fraction (GFR/ERPF) followed a circadian rhythm as well. 4. The circadian rhythms of urine volume and sodium excretion were in phase with the GFR rhythm, but the potassium rhythm had a different phase, probably because urinary potassium is largely derived from tubular secretion. 5. Urinary albumin and β2-microglobulin excretion had a circadian rhythm in phase with the GFR rhythm. 6. The highest quantity of sodium, water and β2-microglobulin was reabsorbed in the daytime; tubular reabsorption, expressed as percentage of the filtered load (fractional reabsorption), had a rhythm with a reversed phase.


2010 ◽  
Vol 81 (1) ◽  
pp. 80-84 ◽  
Author(s):  
Iori MURAI ◽  
Miki SUGIMOTO ◽  
Shuntaro IKEDA ◽  
Shin-ichi KUME

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