scholarly journals Studies on the nutrition of rainbow trout (Salmo gairdneri) Magnesium deficiency: the effect of feeding with a Mg-supplemented diet

1983 ◽  
Vol 50 (1) ◽  
pp. 121-127 ◽  
Author(s):  
D. Knox ◽  
C. B. Cowey ◽  
J. W. Adron

1. For a period of 8 weeks, rainbow trout (Salmo gairdneri), mean initial weight 21 g, were given either a low-magnesium or control diet containing 0·03 and 0·58 g Mg/kg diet respectively. Both groups of trout were then given the control diet for a further 11 weeks.2. Weight gains over the initial 8-week period were lowest in the Mg-deficient trout. Feeding the deficient fish the control diet rapidly improved growth rate until it was the same as that of the control trout.3. Plasma Mg was significantly lower in the Mg-deficient trout at week 8. Feeding with the control diet for 11 weeks did not increase plasma Mg. Few changes were observed in the plasma concentrations of the other electrolytes.4. Renal calcium concentrations were unaffected by dietary Mg levels. Similarly, the renal levels of phosphorus, sodium and potassium all fell within the range found in normal rainbow trout.5. Muscle Mg concentrations were reduced in those trout given the Mg-deficient diet. Feeding with the control diet for a further 11 weeks increased muscle Mg but the level was still significantly lower than that found in trout given the control diet for 19 weeks.6. The bone ash Mg concentration was significantly lower, and the Ca higher, in the deficient fish at week 8, when compared with the control group.7. When compared with the value at the start of the experiment, total bone Mg fell slightly in the deficient trout over the initial 8-week period, but increased in the control group of fish. Feeding with the control diet for a further 11 weeks increased total bone Mg in both Mg-deficient trout and control trout.8. The results show that the Mg deficiency imposed on the rainbow trout was of limited severity and almost complete recovery was obtained when the control diet was fed.

2006 ◽  
Vol 76 (3) ◽  
pp. 111-116 ◽  
Author(s):  
Hiroshi Matsuzaki ◽  
Misao Miwa

The purpose of this study was to clarify the effects of dietary calcium (Ca) supplementation on bone metabolism of magnesium (Mg)-deficient rats. Male Wistar rats were randomized by weight into three groups, and fed a control diet (control group), a Mg-deficient diet (Mg- group) or a Mg-deficient diet having twice the control Ca concentrations (Mg-2Ca group) for 14 days. Trabecular bone volume was significantly lower in the Mg - and Mg-2Ca groups than in the control group. Trabecular number was also significantly lower in the Mg - and Mg-2Ca groups than in the control group. Mineralizing bone surface, mineral apposition rate (MAR), and surface referent bone formation rate (BFR/BS) were significantly lower in the Mg - and Mg-2Ca groups than in the control group. Furthermore, MAR and BFR/BS were significantly lower in the Mg-2Ca group than in the Mg - group. These results suggest that dietary Ca supplementation suppresses bone formation in Mg-deficient rats.


1982 ◽  
Vol 60 (9) ◽  
pp. 2079-2084 ◽  
Author(s):  
G. F. Wagner ◽  
B. A. McKeown

An experiment was conducted to determine if the hyperglycemia that is observed in zinc-stressed fish is also accompanied by changes in the levels of plasma insulin and liver glycogen. Juvenile rainbow trout were exposed to three concentrations of zinc sulphate along with a control group over 31 days. Plasma glucose levels were monitored in each group over the course of the experiment. The group demonstrating the most acute and sustained hyperglycemia (0.352 ppm zinc) was then analyzed along with the controls for changes in plasma insulin (using a teleost insulin radioimmunoassay) and liver glycogen levels. Significant depressions in plasma insulin and liver glycogen levels were observed in the zinc-exposed fish when compared with the controls. These changes are discussed with respect to possible influences of epinephrine, which is elevated in stressed fish, and (or) a direct effect of zinc metal on the pancreatic beta cells.


2000 ◽  
Vol 83 (5) ◽  
pp. 561-568 ◽  
Author(s):  
C. Feillet-Coudray ◽  
C. Coudray ◽  
D. Bayle ◽  
E. Rock ◽  
Y. Rayssiguier ◽  
...  

There is a lack of agreement on index of Cu status and reliable and sensitive biomarkers are still required. The purpose of this present work was to assess in rats the sensitivity of diamine oxidase (DAO) activity, a recently proposed biomarker, to modifications in dietary Cu intake in comparison with other plasma biomarkers of Cu status. We also evaluated the effect of Cu dietary level on Cu and Zn intestinal absorption. Results showed that plasma Cu and plasma caeruloplasmin were significantly decreased at day 8 compared with the control group (7·4 mg Cu/kg diet) while DAO activity was significantly decreased at day 12 of the deficient diet (0·61 mg Cu/kg diet). Cu supplementation (35 mg Cu/kg diet) had no effect on any of the studied biomarkers of Cu status. In Cu-deficient rats plasma Cu and DAO activities were normalized 4 d after return to the control diet while caeruloplasmin was normalized later, at day 11. Apparent absorption values (%) of total Cu or65Cu isotope were significantly increased in the Cu-deficient rats compared with the other groups and similar in the control and the Cu-supplemented groups. The urinary excretion of total Cu or65Cu isotope were increased in the Cu-supplemented group compared with the other two groups. Both apparent absorption and urinary excretion of total Zn or67Zn isotope remained unchanged in the three experimental groups. In conclusion, DAO activity seemed to be less sensitive to Cu deficiency than plasma Cu or caeruloplasmin concentrations. The present study also showed a significant increase in Cu intestinal absorption with dietary Cu restriction but no decrease with Cu supplementation in the rat.


Blood ◽  
1977 ◽  
Vol 49 (4) ◽  
pp. 657-664 ◽  
Author(s):  
RJ Elin ◽  
HK Tan

Abstract This study investigated the anemia of dietary magnesium deficiency in inbred Fisher white rats using freeze-fracture electron microscopy. The plasma membranes of erythrocytes from animals receiving two different magnesium-deficient and control diets were observed at weekly or biweekly intervals for 6 wk. The earliest changes were small plaques on the external surface (ES) and fracture face (PF) of erythrocyte plasma membranes, which occurred after 2 wk of either magnesium-deficient diet. These plaques persisted and increased in size with progressive magnesium deficiency. When fully developed, the plaques consisted of round or oval elevations approximately 30–50 nm in diameter outlined by a narrow raised border. The surface of the plaques was smooth and devoid of intramembranous particles. Incubation of erythrocytes from magnesium-deficient rats in a physiologic solution containing 2 meq/liter magnesium for 1 hr at 37degrees C did not alter the appearance of the plaques. Erythrocytes from control rats, obtained during the same time periods, showed no plaques. Thus, a deficiency of magnesium in rats altered erythrocyte membrane structure.


Parasitology ◽  
1994 ◽  
Vol 108 (3) ◽  
pp. 245-248 ◽  
Author(s):  
P. Maurois ◽  
P.H. Delcourt ◽  
E. Gueux ◽  
Y. Rayssiguier

SUMMARYMice were fed diets containing 960 mg (control), 100 mg (moderately Mg deficient) and 30 mg (severely Mg deficient) of Mg/kg. After 20 days, mice were inoculated with Babesia hylomysci (from Dr Wery, Anvers, Belgium). Significant increases in RBC Mg levels were observed following infection. All the control and moderately deficient mice died from infection, whereas the severely Mg-deficient diet protected mice against infection, as shown by a decrease in parasitaemia and mortality. The decrease in RBC Mg, modifications in membrane properties and increased oxidant stress are possible explanations for the protective effect of severe Mg deficiency. When mice were maintained for 2 months after inoculation on a severely Mg-deficient diet and were then switched to a control diet, all survived and had low parasitaemias. After 1 month, these mice were rechallenged with B. hylomysci and 89% survived.


1987 ◽  
Vol 63 (2) ◽  
pp. 765-769 ◽  
Author(s):  
M. Sadre ◽  
H. P. Sheng ◽  
M. Fiorotto ◽  
B. L. Nichols

The responses of whole body, skeletal muscle, and plasma to oral K loading were studied in K-depleted male rats. Potassium depletion was induced by feeding the rats a K-deficient diet for 4 wk and injecting deoxycorticosterone acetate during the first week. After 4 wk, the rats were growth retarded and hypokalemic (1.9 mmol/l plasma) and had low whole-body and muscle K content, 188 +/- 27 and 276 +/- 19 mmol/kg fat-free dried tissue (FFDT), respectively, compared with 296 +/- 10 and 454 +/- 13 mmol/kg FFDT for the control group. Sodium and water retention also occurred in the K-deficient group. After K depletion, the rats were divided into four groups and received either 0, 1, 2, or 3 intragastric doses of 10 mmol KCl/kg at 8-h intervals. The rats were killed 8 h after the last dose. Control rats were treated similarly. K-depleted and control rats responded differently to K loading. In the normal rats, plasma K remained at 5.0 +/- 0.5 mmol/l, muscle K increased to 502 +/- 24 mmol/kg, and muscle K/N ratio increased from 3.0 to 3.4 mmol/g. In the K-depleted rats, plasma K increased to 7.2 +/- 0.7 mmol/l, muscle K increased to 453 +/- 50 mmol/kg, and muscle K/N ratio increased from 1.8 to 3.1 mmol/g. These data indicate that the capacity of the muscles to accumulate K was impaired after severe K depletion and caused elevated plasma K levels when repletion was complete.


1985 ◽  
Vol 53 (1) ◽  
pp. 149-157 ◽  
Author(s):  
J. G. Bell ◽  
C. B. Cowey ◽  
J. W. Adron ◽  
Aileen M. Shanks

1. Duplicate groups of rainbow trout (Salrno gairdnert) (mean weight 11 g) were given for 40 weeks one of four partially purified diets that were either adequate or low in selenium or vitamin E or both.2. Weight gains of trout given the dually deficient diet were significantly lower than those of trout given a complete diet or a diet deficient in Se. No mortalities occurred and the only pathology seen was exudative diathesis in the dually deficient trout.3. There was significant interaction between the two nutrients both with respect to packed cell volume and to malondialdehyde formation in the in vitro NADPH-dependent microsomal lipid peroxidation system.4. Tissue levels of vitamin E and Se decreased to very low levels in trout given diets lacking these nutrients. For plasma there was a significant effect of dietary vitamin E on Se concentration.5. Glutathione (GSH) peroxidase (EC 1. 1 1. 1.9) activity in liver and plasma was significantly lower in trout receiving low dietary Se but was independent of vitamin E intake. The ratios of hepatic GSH peroxidase activity measured with cumene hydroperoxide and hydrogen peroxide were the same for all treatments. This confirms the absence of a Se-independent GSH peroxidase activity in trout liver.6. Se deficiency did not lead to any compensatory increase in hepatic GSH transferase (EC 2. 5. 1. 18) activity; values were essentially the same in all treatments.7. Plasma pyruvate kinase (EC 2. 7. 1.40) activity increased significantly in the trout deficient in both nutrients. This was thought to be due to leakage of the enzyme from the muscle and may be indicative of incipient (subclinical) muscle damage.


2015 ◽  
Vol 49 (6) ◽  
Author(s):  
A. Hajalshaikh ◽  
M. J. Al-Hassan ◽  
H. E. Mohamed

The objective of this study was to test the effects of sodium selenite (SS) injection on semen characteristics and testosterone plasma concentrations in male Aardi goats. Fifteen animals were assigned into three groups; control (group I, with no supplemental SS); group II; injected intramuscular with 0.1 mg/kg SS body weight; group III injected 0.05 mg/kg SS body weight. Blood samples were collected once weekly (week 0 and four weeks after treatment) in the morning (at 8 am). Semen was collected by electro-ejaculator on a weekly basis post SS supplementation. Sperm count, motility %, progressive motility characteristic; average path velocity (VAP), straight line velocity (VSL), curvilinear velocity (VCL), straightness (STR) and linearity (LIN) were analyzed. Significant differences were found between the two treated-groups and control after week four for motility and progressive motility. After five weeks, significant differences were found between groups, for motility and progressive motility. The live % showed significant differences after five weeks between treated and control groups. After five weeks, significant differences were found between the three groups, for motility and progressive motility. The live % showed significant differences after 5 weeks between different treatments. However, VAP, VSL, VCL, STR, and LIN showed non-significant differences, suggesting that bucks might already have a good motility characteristic. No significant effects of SS supplementation on testosterone plasma levels, and the reported values were 1.28; 1.35, and 1.36 ng/ml for control; group 1, and group 2; respectively. In conclusion, SS improved reproduction in goats <italic>via</italic> the enhancement of semen quality in Aardi goats.


1976 ◽  
Vol 33 (4) ◽  
pp. 1040-1045 ◽  
Author(s):  
C. B. Cowey

Dietary allowances of nutrients have been formulated mainly from growth–response curves. The use of other criteria, especially those which exploit the biochemical role of nutrients, is discussed by reference to three different nutrients, namely thiamin, magnesium, and essential fatty acids.It is shown that erythrocyte transketolase activity provides a nutritional index of thiamin status in turbot (Scophthalmus maximus). The enzyme is saturated with coenzyme (thiamin pyrophosphate) at a dietary thiamin level of 2.6 mg/kg.Assessment of mineral requirements is shown to present special problems because complex interrelationships exist between some dietary minerals. It is shown that dietary magnesium deficiency (4 mg magnesium/100 g diet) leads to renal calcification in rainbow trout (Salmo gairdneri) at dietary calcium levels of 2.7 g/100 g (Ca: P ratio 1: 1). Elevation of dietary magnesium to 100 mg/100 g under these conditions gave freedom from pathology and enhanced growth.Ratios of certain fatty acids in the tissue phospholipids of rainbow trout are known to provide a useful index of essential fatty acid status. These ratios cannot be applied to turbot as this species does not chain elongate and desaturate 18-carbon acids at appreciable rates. Long chain polyunsaturated fatty acids of the ω3 series must be supplied preformed in the diet of turbot.


1974 ◽  
Vol 31 (12) ◽  
pp. 1893-1898 ◽  
Author(s):  
Charlie E. Smith ◽  
Myron Brin ◽  
John E. Halver

Rainbow trout (Salmo gairdneri) fed a pyridoxine-deficient diet developed clinical signs of the deficiency after 8 wk of feeding. Erythrocyte and muscle glutamic pyruvic transaminase (GPT) concentrations were significantly depressed in deficient fish, while liver GPT was significantly elevated. Liver GPT was also elevated in starved trout suggesting the increase in enzyme concentrations was secondary to the deficiency. A normocyte, normochromic anemia, which responded favorably to pyridoxine, developed in pyridoxine-deficient trout. Microscopic lesions were found in gastrointestinal tract, kidney, liver, pancreas, and thymus of deficient fish.


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