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Biomedical subjects

M Ivan

Publications and source records attributed to M Ivan.

At least 73 records · Page 4Linked to original sources
PubMed1982

Chemical composition of sheep bones as influenced by molybdenum supplementation.

Two corn silage diets containing .4 and 10 to 12 ppm molybdenum (dry matter) were fed ad libitum to two groups of six crossbred wethers each. Wethers were kept on these diets for 7 mo, and at slaughter various bones of front legs were dissected. Wethers fed added molybdenum had more molybdenum and zinc in bones than controls. Greater concentration was in the later ossifying portion of the bone than in the more mature areas. Copper, magnesium, phosphorus, calcium, and total ash of sheep bones were unaffected by dietary molybdenum. The compact shaft contained more ash, calcium, phosphorus, and magnesium than the proximal and distal part of the bone. No differences were significant in nitrogen, carbon dioxide, and uronic acid contents of the various bones between the two diets. Site of bone sampling, however, influenced organic composition of bones. Nitrogen concentration was greater at proximal and distal ends of bone than in the shaft. Carbon dioxide varied similarly but in a reciprocal fashion.

Animals↗
PubMed1982

The influence of intraruminal and intraduodenal infusion of picolinic acid on metabolism of 65Zn in sheep.

Two experiments with sheep were carried out to study the influence of picolinic acid on zinc metabolism. In the first experiment, sheep were infused with water into the duodenum and with picolinic acid into the rumen or duodenum. All the sheep were then intraduodenally dosed with 65Zn. In the second experiment, sheep were intraduodenally infused with water or picolinic acid and then intravenously dosed with 65Zn. Necessary sampling of urine, faeces, blood or digesta were carried out in both experiments. The infusion with picolinic acid did not affect the faecal excretion or endogenous secretion of 65Zn but increased the urinary excretion of the radioisotope and ruminal solubility of zinc. However, te duodenal and ileal solubilities of zinc were not affected by the treatment. It was concluded that an exogenous supplement of picolinic acid is not effective in promoting higher absorption of zinc in ruminant animals.

Animals↗
PubMed1981

Distribution of radiomanganese in the rumen of sheep.

Twelve sheep, each prepared with a rumen fistula, were divided into three groups of four and fed three dietary levels of manganese (22,300, and 3000 micrograms/g dry matter) for 11 weeks. The sheep were then dosed with radioactive manganese and samples of rumen contents were taken via the rumen fistula at 1, 7, and 13 h after dosing. The sheep were immediately killed after the last sampling and total rumen contents were mixed and sampled. Rumen fluid was separated frm all samples and fractionated by centrifugation into protozoa plus plant particles, bacteria, and cell-free fraction. The bacterial cells were disrupted and fractionated into cell walls and cytoplasm. The cytoplasmic protein was precipitated with trichloroacetic acid. Although the centration of radiomanganese in rumen fluid decreased with time after dosing from 14.4--17.8 to 6.1--9.3% of dose/L the protozoal and bacterial uptakes of radiomanganese were not significantly different and ranged from 26.5 to 40.6% and 18.9 to 31.7% of total in the rumen fluid, respectively. There was also no effect of dietary concentration of manganese on the uptake and distribution of radiomanganese in the rumen fluid fractions. However, on the average more radiomanganese was found in the bacterial cell walls (48.1--75.3% of total in bacteria) and less in the cytoplasm (51.9--24.7% of total in bacteria) with increasing dietary manganese. Very little radioactivity was found in the trichloroacetic acid precipitated cytoplasm (1.79--0.78% of total in cytoplasm). concentrations of manganese in the bacteria and bacterial cell walls were higher than, and closely related with, those in the diet. Specific activities of radiomanganese decreased in all fractions with increasing dietary manganese. Approximately 15--17% of the total radiomanganese in the rumen contents at 13 h after dosing was found in the protozoal fraction and 10--15% was found in the bacterial fraction; only approximately 21% of the radiomanganese remained in cell-free fraction of the rumen fluid in each dietary treatment.

Animals↗
PubMed1981

Reentrant cannulation of the small intestine in sheep: cannula and surgical method.

The function, design and production of a reentrant cannula for the small intestine of sheep and the corresponding surgical procedure are described. The cannula is molded in one piece from polyvinylchloride plastisol. It consists of a curved intestinal tube joined to a stem with an external elliptical ring on the distal end and a perforated flange that encircles the stem above the intestinal tube. A circular perspex valve with two curved channels was made to fit into the interior of the cannula, making it capable of either a "maintenance" or a "collection" function. The cannula was inserted into the proximal duodenum and(or) terminal ileum of sheep via a 5-cm incision on the antimesenteric side of the intestine. The intestine was attached to the cannula by a Dacron straight arterial graft. This reentrant cannulation method does not require an intestinal transection and a mesenteric incision under the transection. Therefore, little damage was done to the blood and nervous system.

Animals↗
PubMed1981

Silicon in plasma of sheep.

Plasma silicon (Si) concentrations were determined (i) in lambs at 49 days of age reared artificially in confinement (system A), or fed a postweaning diet, or suckled and reared conventionally (system B), (ii) in 2-year-old ewes reared under systems A and B, (iii) in lambs at 49, 70, and 100 days of age reared under system A, and (iv) in lambs (reared under system A) injected with a vitamin D3 preparation. The lambs reared under system A had a significantly lower (P less than 0.01) plasma Si concentration than did lambs reared under system B, but in ewes there was no significant difference (P greater than 0.05) between the 2 rearing systems. Plasma Si concentration of lambs increased (P less than 0.01) as the lambs aged. The vitamin D3 injection had no significant effect (P greater than 0.05) on the plasma Si value.

Age Factors↗
PubMed1980

Effect of dietary manganese on growth and manganese metabolism in sheep.

Three groups of five wethers were each fed ad libitum a practical type diet containing 22, 300, or 3000 ppm of manganese for 8 wk. The wethers then were fistulated and killed 13 h after intraruminal dosing with manganese-54. Several tissues were sampled. Average daily gains and feed/gain ratios of sheep fed diets containing 22 and 300 ppm manganese were similar, but gain was lower and the ratio higher for sheep fed the diet containing 3000 ppm manganese than for those fed other diets. Feed intake was approximately the same for all treatments. Increased dietary manganese increased its concentration in soft tissues and bile. There was also a decrease in the uptake and specific activity of manganese-54 in the liver with increasing dietary manganese. Concentration of copper increased and concentration of zinc decreased in liver of sheep with increasing dietary manganese.

Animals↗
PubMed1979

The effects of nitrilotriacetic acid on solubilities of zinc, copper, manganese, and iron in the stomach of sheep.

Four sheep, each prepared with a rumen fistula and reetrant cannula in the proximal duodenum, were used to study the effects of ruminal administration of nitrilotriacetic acid on solubilities of zinc, copper, manganese, and iron in rumen and duodenal digesta. The sheep received a pelleted diet and were dosed with 0, 300, 600 and 1200 microgram of nitrilotriacetic acid per gram of diet via the rumen fistula. Higher concentration of soluble zinc, manganese, and iron but not copper, were found in the rumen of the sheep when they were dosed with nitrilotriacetic acid. The concentrations increased with increasing dose of the acid. However, only the solubilty of iron was increased in the duodenal digesta. Concentrations of soluble zinc and manganese in the rumen increased, whereas copper decreased, during the first 2 h after feeding. The pattern was reversed thereafter. Changes in the concentrations of soluble during 6 h afther feeding were comparatively small. It is concluded that the solubilty of iron in the stomach of sheep is increased by ruminal administration of nitrilotriacetic acid.

Acetates↗
PubMed1979

Pharmacokinetics and amounts of 25-hydroxycholecalciferol in sheep affected by osteodystrophy.

Amounts of 25-hydroxycholecalciferol in plasma were measured in two groups (A and B) of lambs (Experiment 1) and in two groups (C and D) of wethers (Experiment 2). Groups A (eight lambs) and C (nine wethers) consisted of animals born and raised in total confinement; these animals exhibited an osteodystrophic condition. Groups B (four lambs) and D (10 wethers) consisted of healthy animals born and raised in a conventional barn with free access to an open barn yard (i.e. exposure to sunshine). The 25-hydroxycholecalciferol in plasma of both groups of sick animals, Group A (12.9 ng/ml) and Group C (18.0 ng/ml), were lower than the amounts of the two corresponding groups of healthy animals. Group B (29.2 ng/ml and Group D (32.5 ng/ml). Pharmacokinetic analysis of 25-hydroxycholecalciferol in affected lambs following intramuscular injection of 1,000,000 IU vitamin D3 indicated that transport of vitamin D3 from the site of injection to the liver and its metabolism to 25-hydroxycholecalciferol were rapid. Peak 25-hydroxycholecalciferol occurred at .6 wk, and half-life was 3.1 wk.

Animals↗
PubMed1979

[Combination of antibiotics with analgesic and antipyretic substances (author's transl)].

1. We suggest a combination of analgesic and antipyretic medicaments in medical treatments with antibiotics. Thus, the antibiotic is increased and microorganisms, resistant to antibiotics, are converted into sensitive forms. 2. The results of the in vitro used method (diffusion plate test) are in accordance with the results obtained using these combinations in therapy. 3. This method should not be applied to strains that are sufficiently sensitive to antibiotics, since the results would be contrary to the afore mentioned. 4. The effects of a combination are additionally synergistic in the case of strains originally sensitive. 5. This method offers great possibilities for multiplying treatments with antibiotics. We recommend to give standardized combinations of antibiotics with analgesic and antipyretic medicaments per os.

Analgesics↗
PubMed1978

Manganese status of pasturing ewes, of pregnant ewes and doe rabbits on low manganese diets and of dairy cows with cystic ovaries.

Four experiments were conducted to obtain information on the manganese (Mn) status of ewes, doe rabbits and dairy cows with cystic ovaries. Manganese was not concentrated specifically in any one tissue or organ but the use of 54Mn has indicated that the isotope was retained by the liver for a longer time. Significantly lower (P less than 0.01) levels of Mn were observed in the liver, kidney and blood of pregnant ewes fed a synthetic diet containing low levels (5 ppm) of Mn than those that were supplemented with 60 ppm Mn. It would appear that the determination of blood Mn concentration would provide a valuable diagnostic tool for the assessment of the Mn status of the pregnant ewe and could be more reliable than data based on tissue (liver, kidney, ovary) levels of Mn. The cortical stroma of dairy cows with cystic ovaries had lower Mn contents than those cows that were without cystic ovaries. The data on blood suggests that cystic ovaries cannot be diagnosed by blood Mn levels if Mn was indeed a contributing factor of the development of this condition. The doe rabbit responded to supplemental dietary Mn in a manner analogous to the ewes.

Adrenal Glands↗
PubMed1977

Influences of barley and oat silages for beef cows on occurrence of myopathy in their calves.

Sixteen pregnant Shorthorn cows were winter-fed either oat or barley silage, both of which were low in selenium (less than .1 ppm). Two months before calving, as well as at calving and a month later, four cows on each diet were given intramuscularly a preparation containing 1360 IU of vitamin E and 30 mg selenium as sodium selenite. Barley silage lipids contained higher linoleic (33.2 versus 22.3%) and palmitic acids (32.3 versus 23.1%), and lower oleic (6.3 versus 22.1%) and linolenic acids (20.9 versus 30.9%) than oat silage. Three calves born from the untreated dams on barley silage died from nutritional muscular dystrophy by 50 days of age whereas none of the calves either from the untreated cows on oat silage or from any of the selenium/vitamin E treated cows. Milk from untreated cows fed barley silage contained a higher proportion of linoleic acid than that from treated cows or from those on oat silage. The incidence of nutritional muscular dystrophy was associated closely with ingestion by the calves of an increased amount of dietary dienoic acid. It appears an advantage to include oat silage in winter feeding programs for beef cows to reduce the risk of development of nutritional muscular dystrophy in the offspring.

Animal Feed↗
PubMed1977

Effect of human chorionic gonadotropin on the transport of manganese and zinc and tissue uptake of radioactivity following subcutaneous administration of tritiated estrone in manganese deficient and nondeficient rabbits.

Twenty-four eight month old virgin New Zealand doe rabbits were used in an experiment designed to study the effect of human chorionic gonadotropin on the transport of 54Mn and 65Zn in their tissues. Although human chorionic gonadotropin treatment did not result in any change in 65Zn transport, that of 54Mn was affected. In another experiment, the tissue uptake of tritiated estrone was studied in manganese deficient and nondeficient rabbits. There were no differences in radioactivity uptake between the two diets but the pattern of tissue uptake was different from other reports.

Animals↗
PubMed1977

Effects of level of dietary sulfur on the growth performance and blood mineral profile of sheep fed urea-supplemented corn silage.

Several blood constituents were measured in whether receiving a basal diet of corn silage, urea and a mineral-vitamin supplement to which various levels of sulfur (S) were added. The amounts of S in the total diets were: .16, .26, .38, .47 and .57% of dry matter. After a six-month experimental period, the levels of copper and iron in the plasma and of urea and manganese in the blood had been effected, lower levels being associated with higher levels of dietary S. Plasma zinc and magnesium levels showed a quadratic response to dietary S levels. However , plasma calcium levels and blood selenium levels were not significantly affected. Plasma sulfate-S content was higher in those animals receiving higher levels of S in the diet. The quantity of S ingested did not significantly affect voluntary feed intake, growth rate, or diet digestibility; however, nitrogen retention was lowered. The higher dietary S levels resulted in higher urinary excretion of the element, while fecal S remained unchanged.

Animal Nutritional Physiological Phenomena↗
PubMed1976

Flow rates of components in digesta of pigs prepared with re-entrant cannulas in the proximal duodenum and terminal ileum, and fed semipurified, hard wheat, and soft wheat diets.

Four pigs prepared with re-entrant cannulas in the proximal duodenum and terminal ileum were used to study flow rates of total digesta, insoluble dry matter, nitrogen, and amino acids entering and leaving the small intestine. The pigs received a semipurified diet, a hard wheat diet, or a soft wheat diet. These were approximately isonitrogenous. A higher rate of passage of digesta through the proximal duodenum and terminal ileum were measured in pigs receiving the hard wheat diet. Peak flow of digesta at the duodenum of all pigs occurred at 1 h post feeding. Peak flow of digesta at the ileum occurred at 9 h post feeding on the soft wheat diet, but somewhat earlier on the hard wheat and semipurified diet. More nitrogen and essential amino acids flowed in the solid fraction of duodenal digesta during the first 2 h post feeding for the wheat diets and 4 h post feeding for the semipurified diet. It was concluded that flow rate of most nutrients from the stomach and through the small intestine of pigs is modified by the composition and texture of the food ingested. It is postulated that efficiency of mixing of digesta with digestive secretions in the stomach is a major factor influencing rate of flow.

Amino Acids, Essential↗
PubMed1976

Effects of zinc, copper, and manganese supplementation of high-concentrate ration on gastrointestinal absorption of copper and manganese in Holstein calves.

Sixteen Holstein bull calves were fed a high-concentrate ratio supplemented with zinc, copper, and manganese, alone or in combination, for 10 wk. After 6 days of preliminary feeding of chromic oxide, fecal grab-samples were collected for 6 days. Calves were slaughtered, and samples of the contents of the reticulo-rumen, omasum, abomasum, small intestine, cecum, and large intestine were analyzed for chromic oxide, copper, and manganese. Absorption along the gastrointestinal tract, measured by comparison of one segment with the previous segment, indicated net secretion of copper in the abomasum but net absorption from the rest of the tract. The exception was that net secretion into the reticulo-rumen was associated with low dietary copper. Net secretion of manganese was mainly in the small intestine and cecum in all treatments. A higher proportion of copper apparently was absorbed when this mineral was supplemented in the ration. However, absorption of manganese was decreased slightly when manganese was supplemented in the ration. Reabsorption of manganese in the large intestine was probably greater than that of copper.

Absorption↗