Biomedical subjects

M Hidiroglou

Publications and source records attributed to M Hidiroglou.

At least 55 records · Page 3Linked to original sources

PubMed1991

Metabolic changes in the rumen following protozoal inoculation of fauna-free sheep fed a corn silage diet supplemented with casein or soybean meal.

Fauna-free wethers were fed bi-hourly a corn silage diet containing casein or soybean meal as a protein supplement. The wethers were inoculated via rumen cannula with a mixed population of ruminal ciliate protozoa. Ruminal fluid was sampled daily for 4 d before and for 13 d (and on d 28) after inoculation. Protozoal populations reached peak numbers on d 8 and decreased to new levels after d 9 for wethers on both supplements. Protozoa decreased (P less than 0.01) the concentrations of total volatile fatty acids, increased (P less than 0.01) the pH and decreased (P less than 0.01) he concentrations of total and non-ammonia nitrogen in ruminal fluid. The concentrations of ammonia nitrogen increased with increasing numbers of protozoa for wethers on both supplements, but the concentrations decreased after d 7 to approximately pre-inoculation levels for the casein-supplemented diet. The increasing numbers of protozoa were associated with the increased concentrations of total and free alpha-amino nitrogen (P less than 0.01) and sulfide (P less than 0.05) and with the decreased concentrations of soluble Cu (P less than 0.05) in the ruminal fluid in soybean meal-supplemented wethers but not in those receiving casein. It was concluded that dietary proteins with differing physical characteristics are metabolized to a different extent by ruminal ciliate protozoa, which in turn can affect the metabolism of other dietary nutrients such as nitrogen and sulfur and contribute to copper-sulfur interaction.

Ammonia↗

PubMed1991

Effects of selenium and vitamin E administration on breeding of replacement beef heifers.

Forty-eight heifers were given selenium and/or vitamin E or no supplementation from age of weaning (8 months) for 6 months prior to breeding. Blood plasma levels were monitored and some reproductive traits were assessed. The overall pregnancy rate (33%) in the control group was significantly (P less than 0.05) lower than in the vitamin E-supplemented groups (58-83%). Age of first heat, breeding and calving were unaffected by vitamin E and/or selenium supplementation.

Animal Nutritional Physiological Phenomena↗

PubMed1991

Comparative studies on bioavailability and tissue uptake of two intraruminally or intraperitoneally administered esters of alpha-tocopherol in sheep.

An experiment was conducted to compare the bioavailability of dl-alpha-tocopherol acetate (TA) with that of dl-alpha-tocopherol nicotinate (TN) when administered to sheep, as a single dose, either into the rumen or the peritoneal cavity. A total of 16 sheep were used in a factorial design, with 4 sheep/treatment at the interaction level. In addition, 5 sheep that received no supplemental alpha-tocopherol, were euthanatized at the end of the trial to provide base-line data for tissue alpha-tocopherol concentrations. Curves were fitted to the plasma alpha-tocopherol concentration values, taken over 180 hours after administration of the esters. Availability of TA was greater than TN, as evidenced by the significantly higher curve parameter values (P less than 0.05) and tissue concentrations (P less than 0.05). Route of administration had a marked effect on availability of TA (P less than 0.001), but not of TN.

Animals↗

PubMed1990

Copper deficiency and posterior paralysis (Shalal) in small ruminants in the Sultanate of Oman.

A posterior ataxia or paralysis in goats and sheep is a syndrome known as Shalal within the Sultanate of Oman. An investigation was carried out into the etiology of the syndrome. Samples of blood and tissues were obtained from normal and Shalal-affected goats and sheep. Samples of feed were collected from the affected areas of the Sultanate. Chemical analyses of samples showed that affected animals suffered from severe copper deficiency in spite of sufficient copper contents in feed. However, concentrations of sulphur and iron in the feed were high. It was concluded that the Shalal syndrome in Oman is the condition generally known as swayback or enzootic ataxia caused by conditioned copper deficiency. The deficiency is probably due to copper-sulphur and copper-iron interactions in the rumen, enhanced by feeding of fresh roughage containing rumen degradable proteins.

Animal Feed↗

PubMed1990

Monitoring vitamin E pools in sheep tissue and plasma after intravenous dosing of radiotocopherol.

The fate of radiotocopherol was studied in plasma and tissues of sheep at various intervals after injection of single intravenous doses of 3H-labelled D-alpha-tocopherol. Plasma samples were taken at regular intervals after dosing and selected tissues were taken from all sheep after slaughter and assayed for radioactivity and D-alpha-tocopherol. Sheep were killed in groups of five at 24, 72, 96, 272 and 432 h post-dosing. Plasma profiles were characterized as a sum of three exponential terms. A principal component analysis of tissue concentrations was carried out to identify tissues with parallel profiles of log (disintegrations/min per microgram) over time. Five groups of tissues with distinct uptake and elimination processes were identified. The D-alpha-tocopherol in the liver and heart appeared to be consistent with the post-distributive kinetics of a highly perfused shallow compartment, while lung kinetics appeared to reflect a non-linear kinetic process. The third group, which included the spleen, neck brachiocephalicus muscle and pancreas, had depletion rates parallel to those of plasma for 24-272 h, but slower decreases than plasma over 272-432 h. Hip gluteus muscle and kidney comprised a fourth group, with depletion parallel to plasma rates for 24-96 h but progressively slower than plasma decreases over 96-272 h. Adrenal kinetics resembled the fourth group, but had a more rapid decrease in specific activities over 24-72 h.

Animals↗

PubMed1990

Effect of vitamin E and selenium supplementation on some immune parameters following vaccination against brucellosis in cattle.

Twenty-four 7-mo-old beef heifers (Charolais Simmental cross), weighing 213 kg, were used to determine the effect of vitamin E (VitE) and(or) selenium (Se) supplementation on the humoral response to a standard dose of Brucella abortus strain 19 vaccine and on the levels of naturally occurring immunoglobulins (Ig) to several antigens. The treatments were as follows: Group 1, no supplement; Group 2, supplementation with 6 g of elemental Se; Group 3, supplementation with 1,400 IU/d of VitE; and Group 4, Se and VitE supplements combined. There were no significant differences in anti-B. abortus IgG1, IgG2, or IgM antibody levels due to Se, VitE or Se/VitE treatments; the concentrations of IgA antibody were too low to be measured with the ELISA test used. Statistical analysis revealed that the levels of total and IgM natural antibody to Salmonella typhimurium were higher in Group 3. Perhaps VitE supplementation given in conjunction with B. abortus vaccine enhanced the production of antibody to S. typhimurium in several animals whose humoral system had been activated by previous exposure to this organism.

Animals↗

PubMed1990

Effects of elevated iodine in milk replacer on calf performance.

Calves were fed milk replacer containing .57, 10, 50, 100, or 200 ppm iodine (from ethylenediaminedihydroiodide) in DM, from 3 to 38 d of age, to estimate the minimum toxic concentration of iodine. Only the 200 ppm iodine intake reduced weight gains, DM intake, feed efficiency, and DM digestibility. At the 100 and 200 ppm iodine intakes, protein digestibility was reduced, and calves showed typical symptoms of iodine toxicity (nasal discharge, excessive tear and saliva formation, and coughing from tracheal congestion). Thyroid iodine increased with every elevation in iodine intake. Iodine in plasma, bile, and non-thyroid tissues started to increase at the 50 ppm intake and, except for muscle, tended to increase again at the 100 and 200 ppm intakes. Thus, the preruminant calf tolerated up to 50 ppm iodine in milk replacer DM for 5 wk postpartum. However, as iodine concentrations in plasma and nonthyroid tissues started to increase at 50 ppm iodine, an upper limit of 10 ppm would be more preferable.

Animal Feed↗

PubMed1990

Plasma vitamin E response in sheep dosed intraruminally or intraduodenally with various alpha-tocopherol compounds.

A total of 24 sheep were used to study two routes of vitamin E administration: intraruminal (IR) and intraduodenal (ID). For each route of administration, 12 sheep were divided into 3 groups of 4, and each group received one of the following vitamin E treatments (mg/kg body weight): treatment 1, D-alpha-tocopherol (60 mg); treatment 2, D-alpha-tocopherol acetate (70 mg); treatment 3, DL-alpha-tocopherol (90 mg). The results showed that two major indices of bioavailability, i.e. concentration maximum and the area under the plasma concentration time-curve, were higher following IR administration than ID administration for all three vitamin E compounds used in this experiment. In sheep dosed intraruminally no difference was observed between the three vitamin E preparations in their plasma vitamin E response. For the ID administration the peak of plasma vitamin E concentration was lower after D-alpha-tocopherol acetate dosing than with the other two preparations. The results indicated a beneficial effect of rumen environment on the availability of vitamin E supplements.

Animal Nutritional Physiological Phenomena↗

PubMed1990

Assessment of the role of manganese in congenital joint laxity and dwarfism in calves.

Pregnant beef cows were winter-fed (November 15 to calving) hay (24 cows), red clover silage (21 cows) or grass silage (52 cows). Blood samples were taken from each cow in December and February. A condition of congenital joint laxity and dwarfism was observed in 38% and 28% of calves born to cows fed red clover silage and grass silage, respectively. None of the calves born to hay-fed cows were affected by the condition. The congenital joint laxity and dwarfism was associated with a lower serum manganese concentration in silage-fed cows than in hay-fed cows. However, manganese concentrations were similar in red clover silage, grass silage and in hay. A lower bioavailability of manganese in silages other than in hay, resulting in an apparent manganese deficiency in silage-fed cows, is suggested as a possible factor contributing to the etiology of congenital joint laxity and dwarfism in calves.

Animal Feed↗

PubMed1990

Vitamin E concentrations in blood plasma of sheep and in sheep tissues after a single intraruminal or intraperitoneal administration of DL-alpha-tocopheryl acetate.

Twenty-five yearling wethers, weighing 40 to 45 kg were used in a trial designed to compare the effect of the route of administration of vitamin E upon plasma and tissue vitamin E status. Five control sheep without vitamin E administration were killed at the beginning of the trial. Of the remaining 20 sheep, 10 were given DL-alpha-tocopheryl acetate intraruminally and 10 by intraperitoneal injection. Of these, 10 wethers were killed three days after dosing (five from each treatment, IR3 and IP3) and the remaining wethers were killed eight days after dosing (IR8 and IP8). Blood samples were taken throughout the trial from sheep on the IR8 and IP8 treatments. Samples of whole adrenal gland, heart, liver, kidney, brachiocephalicus muscle, lung, pancreas and spleen were taken from all sheep at slaughter and were analysed for their vitamin E content. The blood plasma results showed that the most important index of vitamin E bioavailability, the area under the plasma concentration versus time curve, was greater in the intraperitoneally than intraruminally dosed sheep. There was a higher concentration of vitamin E in the tissues from the intraperitoneal group than the intraruminal group three days after the intraperitoneal injections. The results suggest that the greatest responses in vitamin E concentration in plasma and the tissues were recorded in sheep following intraperitoneal rather than intraruminal dosing with DL-alpha-tocopheryl acetate.

Administration, Oral↗

PubMed1990

Response of plasma and tissue D-alpha-tocopherol in sheep to graded dietary levels of dl-alpha-tocopheryl acetate.

The objective of this experiment was to establish the validity of using plasma alpha-tocopherol values as an index of alpha-tocopherol status in sheep. alpha-tocopherol values were obtained for tissues and blood of 40 sheep given four different dietary intakes of dl-alpha-tocopheryl acetate. Group 1 sheep were given a basal diet containing 25 to 32 mg dl-alpha-tocopheryl acetate kg-1 while groups 2, 3 and 4, comprising 10 sheep each, received the basal diet plus 200, 400 and 600 mg dl-alpha-tocopheryl acetate per sheep, respectively. Blood samples were obtained at zero time and then twice weekly for eight weeks, at which time sheep were killed and organs retrieved for tissue alpha-tocopherol analysis. Tocopherol concentrations were higher in all tissues (P less than 0.001) of sheep fed the vitamin E supplemented diets than the basal diet. Vitamin E stored in the liver of sheep at the end of the experiment (eight weeks) showed a linear response to the level of vitamin E in the diet. Blood plasma vitamin E concentrations increased following vitamin E supplementation, but no direct relationship was found between vitamin E intake and plasma vitamin E content.

Animals↗

PubMed1990

Kinetics of intravenously administered vitamin E in sheep and its biliary excretion.

This report describes studies of vitamin E kinetics and biliary excretions of vitamin E in 7 sheep administered [3H]-d-alpha-tocopherol (2 microCi/kg body weight) intravenously. Blood samples were periodically withdrawn from the jugular vein and bile samples from a biliary fistula for 56 h after intravenous administration of the [3H]-d-alpha-tocopherol. The kinetic data were modelled as 2-exchanging compartments. Radiovitamin E was rapidly distributed into the peripheral compartment and was widely distributed throughout the body. A high level of radioactivity was recorded in the lung, liver, spleen and renals. The concentrations of d-alpha-tocopherol in bile and plasma did not run parallel. The pattern of biliary radioactivity concentration suggests a rapid biliary clearance.

Animals↗

PubMed1989

Providing vitamin D to confined sheep by oral supplementation vs ultraviolet irradiation.

Serial vitamin D3 (D3) and 25-hydroxyvitamin D3 (25 OH D3) concentrations of plasma were measured in confined, shorn sheep that had either been supplemented with vitamin D3 (50 micrograms/d) or exposed daily to ultraviolet irradiation (UVI). In the sheep administered D3 orally, plasma D3 increased continuously until d 35. This was followed by small fluctuations of the plasma D3 concentrations until a plateau was reached after 56 d of supplementation (.94 ng/ml plasma). Plasma 25 OH D3 concentrations increased continuously and plateaued between d 65 to 75 at about 21 ng/ml plasma. In the UVI sheep, plasma D3 and 25 OH D3 concentrations increased continuously for the first 49 d, then plateaued at 2.03 ng D3 and 29.6 ng 25 OH D3/ml. When a plateau was reached in plasma 25 OH D3 concentrations in both treatment groups, a 3H-labeled tracer dose of 25 OH D3 was given i.v., and disappearance of the 3H-labeled 25 OH D3 was followed. The UVI group had a faster decline in specific activities during the first exponential phase but a slower decline during the prolonged terminal elimination phase. These differences are reflected in the intercompartmental transfer rates. Our data indicate that UVI is as effective as oral vitamin D3 supplementation for improving vitamin D status of confined sheep.

Animals↗

PubMed1989

Tolerance of the calf for excess copper in milk replacer.

Calves were fed milk replacer containing 10, 50, 200, 500, or 1000 ppm Cu, from 3 d to 45 d of age, to estimate the Cu concentration that would adversely affect calf performance. Weight gains and feed efficiency were similar for 10 and 50 ppm Cu but were reduced at 200 and 500 ppm Cu. All calves survived 500 ppm Cu and lower intakes, but only 4 of 7 calves survived the 1000 ppm concentration. Typical clinical symptoms of chronic Cu toxicity and hemolytic crisis were evident for the 1000 ppm calves before death. Additional 1000 ppm Zn prevented deaths for 1000 ppm Cu, but calf performance was poor. Increased Cu intakes elevated plasma ceruloplasmin and glutamic oxalacetic transaminase activity, reduced packed cell volume (hematocrit), markedly increased fecal excretion of Mo and Zn, increased Cu concentration of liver, muscle, heart, blood, and bile, and decreased Mo and Zn in liver. We found 50 ppm Cu a safe intake where milk replacer contained 48 ppm Zn and 1.1 ppm Mo. However, at lower intakes of these elements, and for longer feeding periods than 6 wk, the calf may be much more susceptible to Cu toxicity.

Animals↗

PubMed1989

Mammary transfer of vitamin E in dairy cows.

Milk vitamin E from eight dairy cows was analyzed for vitamin E by HPLC during the 1st mo of lactation. Colostrum gave a mean value of 1.9 micrograms alpha-tocopherol/ml while concentrations of fresh milk averaged .3 microgram alpha-tocopherol/ml. D-gamma-tocopherol concentrations were observed in very small amounts. When six cows at the end of the 1st mo of lactation were injected intraperitoneally with an emulsion of dl-alpha-tocopherol acetate (5 g), plasma and milk concentrations of alpha-tocopherol were increased from their original values of 4.5 micrograms/ml plasma and .3 microgram/ml fresh milk to 10.9 micrograms/ml plasma and 1.6 micrograms/ml fresh milk, 12 h later. The results show that intraperitoneal administration of vitamin E to dairy cows in an effective way of increasing plasma and milk tocopherol concentration.

Animals↗

PubMed1989

Effect of intraperitoneally injected tocopherol on vitamin E status of dairy cow.

The effect of intraperitoneal (IP) administration of vitamin E on the concentration of tocopherol in the blood and milk of cows was studied. Two trials were carried out using a total of twenty-four Holstein cows. In the first trial, two doses of dl-alpha-tocopherol (1 g and 5 g) were given to six cows in each treatment. Administration of 1 g caused a small increase in blood and milk concentrations; dosing with 5 g IP caused appreciable increases in both plasma and milk concentrations. Plasma and milk concentrations peaked 1 d after dosing with a maximum value of 10.7 micrograms/ml plasma and 1.39 micrograms/ml milk. Then there was a continuous decline during the 14 d experimental period. In the 2nd trial, twelve cows were dosed IP with the acetate form of vitamin E. Six cows were given 5 g and six others 10 g of dl-alpha-tocopherol acetate. Maximum plasma vitamin E concentrations occurred at d 2 (7.4 micrograms/ml) and d 1 (10.9 micrograms/ml) for the cows dosed with 5 and 10 g of the ester form, respectively. Milk vitamin E concentrations were significantly higher (P less than .05) during the first 4 d for cows dosed with 10 compared to those given 5 g. During the 14 d experimental period, maximum milk vitamin E concentration for the 10 g group was 141 micrograms vitamin E/g fat 2 d after dosing and for the 5 g group 62 micrograms vitamin E/mg fat also at 2 d after dosing. The technique of dosing cows with vitamin E by IP proved to be an effective way for increasing vitamin E status. These treatments had no effect on cholesterol content of milk fat. However, it was noted that cholesterol level was lower in PM milking as compared to AM milking.

Animals↗

PubMed1989

Effects of selenium and copper administration on blood selenium and copper profile of cattle.

Forty yearling shorthorn heifers were winter-fed barley silage, a diet low in copper and selenium. The animals were divided into 4 groups of 10 animals each. One group was unsupplemented, while other treatments were copper (Cu), selenium (Se), or combined Cu-Se administered by subcutaneous injections. Low Cu and Se concentrations were observed in the blood plasma of the unsupplemented group. The administration of Cu and Se raised the blood plasma Cu and Se concentrations in the heifers. However, Cu or Se administration had no effect on the growth of heifers and there was no interaction between the Se and Cu treatments.

Animals↗

PubMed1988

Pharmacokinetic disposition in sheep of various vitamin E preparations given orally or intravenously.

1. Increases in plasma tocopherol concentrations were compared in sheep after a single oral administration of (per kg body-weight): 67 mg D- and 91 mg DL-epimers of alpha-tocopherol, and 74 mg D- and 100 mg DL-epimers of alpha-tocopheryl acetate, or intravenous administration of DL-alpha-tocopherol and DL-epimers of DL-alpha-tocopheryl acetate. 2. The results showed that biological availability was higher after D-alpha-tocopherol dosing than after the other forms. Intravenous administration of D-alpha-tocopherol acetate was a more effective way of dosing in sheep than equivalent intravenous amounts of DL-alpha-tocopheryl acetate or DL-alpha-tocopherol.

Administration, Oral↗