Biomedical subjects

M Kirchgessner

Publications and source records attributed to M Kirchgessner.

At least 109 records · Page 6Linked to original sources

PubMed1993

[Effect of bovine growth hormone on performance criteria of dairy cows during summer feeding with grass. 1. Feed intake and protein and energy supply].

The influence of long-term administration of bovine growth hormone (bGH) with prolonged release (Somidibove from Lilly Germany GmbH, section Elanco, 640 mg/28 d) in six consecutive injection periods on feed intake under summer feeding conditions with grass feeding ad libitum was investigated. After a pretreatment period of 22 days 30 dairy cows were divided into 15 blocks with two cows each in consideration of milk yield, days postpartum and number of calving. In each block the bGH-treated animal received the same concentrate supply as the corresponding control animal which was supplemented in order to requirement. In a 42 day posttreatment period without bGH-injection possible effects of bGH-treatment on feed intake (grass silage and maize silage) was investigated. The first injection was administrated 75 days postpartum, respectively. During all six injection periods feed intake corrected to the pretreatment period was increased by 0.63 kg DM/animal.d resulting from a higher grass intake in the bGH-treated dairy cows compared to the control group. This difference in feed intake raises from 0.40 kg DM/animal.d in the first injection period up to 0.84 kg DM/animal.d in injection period six and continued in the posttreatment period without bGH-injection (+0.89 kg DM/animal.d). The higher feed intake of grass in the injection periods by the bGH-treated dairy cows resulted in an increased energy intake sufficient on average for the production of 1.2 kg milk/animal.d. Possibilities and limits of a sufficient nutrient supply in bGH-treated dairy cows by an increasing intake of grass are discussed.

Animals↗

PubMed1993

[The effect of bovine growth hormone on the production criteria of dairy cows during summer feeding with grass. 2. Milk yield, milk composition and live weight].

The influence of long-term administration of bovine growth hormone (bGH) with prolonged release (Somidibove from Lilly Germany GmbH, section Elanco) on milk yields, milk composition and live weights in six following injection periods of 28 days each was investigated. 30 dairy cows were divided into 15 blocks of two, each pair in consideration of milk yield in a preperiod, days postpartum and number of calving. One animal in each block received the bGH treatment (640 mg bGH/28 days). Concentrate feeding of the bGH-treated cows acted according to the control animal in each block. The forage intake from grass was ad libitum. During all six injection periods the bGH-treated cows had a higher milk yield of 1.3 kg/day (P < or = 0.13). Milk fat content was unchanged, milk protein content was in relation to the changes from preperiod significantly higher in the bGH-treated group. Each injection resulted in a curvilinear response curve of daily milk yield, milk fat and milk protein content. Milk lactose content was not affected by the bGH-treatment.

Animals↗

PubMed1993

[Effect of feeding protected arginine on food intake, milk yield and growth hormone and amino acid levels in blood plasma of cows during the summer feeding period with grass].

The influence of a daily additon of 130 g arginine and 30 g lysine in a ruminally protected form on the content of growth hormone, amino acids and urea in blood plasma, milk yield and components and also feed intake under summer feeding conditions in an experimental period of eight weeks was investigated. The forage intake from grass was ad libitum. After a preperiod a total of 24 dairy cows were divided into 12 blocks, two cows in each, to consider milk yield, days postpartum and number of calving. The concentrate level of the treated group acted according to the control animals in each block. The growth hormone contents and the concentrations of arginine and lysine in blood plasma were not influenced by the addition of protected arginine. Urea content in blood plasma was increased in the treated cows tendentious in week 2 and significantly in the weeks 5 and 8. The decrease in milk yield in comparison with the preperiod was diminished in the arginine group by an average of 0.9 kg/d compared with the control, in the case of milk fat content it was significantly lowered. The milk protein and lactose contents were not changed by the treatment. The average daily forage intake was unchanged in the arginine group.

Amino Acids↗

PubMed1993

Effects of somatotropin treatment on growth performance, carcass traits, and the endocrine system in finishing beef heifers.

The objectives of this study were to investigate the effects of exogenous somatotropin on growth performance and carcass traits and on concentrations of somatotropin (ST), IGF-I, insulin, glucagon, free fatty acids (FFA), and glucose in plasma of finishing Simmental beef heifers. Three treatment groups, which included 12 heifers each, received a subcutaneous injection of a slowly released recombinant bovine somatotropin (rbST) at two doses (320 and 640 mg, respectively) or a placebo at 2-wk intervals. Treatments began at an average BW of 286 kg and continued until the animals were slaughtered at approximately 520 kg. Heifers had ad libitum access to corn silage and received 1.8 kg/d of concentrate. A before-feeding blood sample was collected from the jugular vein immediately before and 1 wk after each injection during treatment. Treatment tended to increase ADG and to reduce energy consumption per kilogram of gain, whereas feed and energy intake were not altered. Dressing percentage and conformation did not seem to be affected by treatment. Treatment led to a dose-dependent reduction of fat tissue in carcass as well as in kidney fat and to a simultaneous increase of lean tissue (P < .05). Furthermore, treatment caused moderate increases of ST in both treated groups, whereas IGF-I concentrations increased markedly soon after the beginning of the treatment. Insulin and FFA concentrations were elevated in treated groups compared with controls. Glucagon concentrations were not altered by treatment. Effects on growth performance and carcass characteristics are discussed in view of metabolic and endocrine changes.

Adipose Tissue↗

PubMed1993

Effects of different levels of dietary selenium and vitamin E on the humoral immunity of rats.

The aim of the present study was to investigate whether the level of selenium and selenium/vitamin E supply influences the humoral immunity of rats. In order to detect the effect of Se supply and age, 36 weaned Sprague-Dawley rats divided into two equal groups were killed after 22 or 45 experimental days by decapitation (Exp. I). In Exp. II 9 groups of 10 rats each were exposed to each combination of deficient, normal or excessive selenium with a vitamin E supply and killed after 44 days. The basic (deficiency) diet which was the same in both experiments contained 0.04mg Se and 8mg vitamin E per kg dry matter. The supplementation per kg diet was 0 or 0.2mg Se and 30mg vitamin E in Exp. I and 0, 0.2 or 1mg Se and 0, 30 or 200mg vitamin E in Exp. II. The concentration of selenium in serum, liver and spleen samples and the activity of glutathione peroxidase, which were determined to define the selenium status of the animals, corresponded well to the required supply situation. The immunoglobulins of type IgA, IgM and IgG with the subtypes IgG1, IgG2a, IgG2b and IgG2c were measured by immunoelectrophoresis. In both experiments selenium deficiency decreased the values of the IgG groups only nominally, IgA was not changed. IgM was significantly reduced, especially with prolonged selenium deficiency and simultaneous vitamin E deficiency. An excessive selenium supply compensated to a great extent for the effects of vitamin E deficiency on IgG and IgA.

Animals↗

PubMed1993

Concentration of free calcium in erythrocytes of lead-depleted rats.

The concentration of Ca(2+)-ions in erythrocytes of lead-depleted rats was estimated using the fluorescent Ca(2+)-indicator fura-2. The lead-depleted animals of the F1 generation showed an elevated Ca(2+)-concentration, whereas in the Po generation there was no difference in the Ca(2+)-concentration between depletion and control group. The elevation of Ca(2+)-ion concentration of lead-depleted rats could be caused by a reduction in Ca-Mg-ATPase activity in lead-depletion and could possibly lead to a decreased mean corpuscular volume (MCV) of erythrocytes.

Animals↗

PubMed1992

Studies on the methanolysis of small amounts of purified phospholipids for gas chromatographic analysis of fatty acid methyl esters.

The methanolysis of small amounts of purified phosphoglycerides and sphingomyelin was studied and a quantitative comparison of five methods for the methanolysis of standard phosphoglycerides was made. These methods were based on methanolysis with boron trifluoride-methanol, methanolic sodium methoxide (at ambient temperature and with heating) and methanolic sulphuric acid. A further method was based on saponification with methanolic sodium hydroxide and subsequent esterification with boron trifluoride-methanol. Under the experimental conditions, only the sodium methoxide-catalysed method at ambient temperature gave complete methanolysis of phosphoglycerides. For methanolysis of sphingomyelin, boron trifluoride-methanol, methanolic sulphuric acid and methanolic hydrochloric acid were used. It was found that complete methanolysis of sphingomyelin takes 15 h at 90 degrees C. Based on these results, procedures for the methanolysis of phosphoglycerides and sphingomyelin separated by high-performance liquid chromatography are presented.

Animals↗

PubMed1992

Simultaneous determination of amounts of major phospholipid classes and their fatty acid composition in erythrocyte membranes using high-performance liquid chromatography and gas chromatography.

A method for the simultaneous determination of amounts of major phospholipid classes and their fatty acid composition in erythrocyte membranes is described. The method consists in extraction of phospholipids from erythrocyte membranes, separation of phospholipid classes by high-performance liquid chromatography, methylation of phospholipids and determination of phospholipid-bound fatty acids by capillary gas chromatography. The amounts of phospholipid classes are calculated from the total weight of phospholipid-bound fatty acids and their average molecular weights. The method was applied to erythrocytes from rats. The results show that the method is reproducible and is useful for the determination of amounts of phospholipid classes and their fatty acid composition in small blood samples.

Animals↗

PubMed1992

[Energy balance in repeated under- and overnutrition in model studies in sows].

In a model experiment eight adult sows were used to examine the effect of successive periods of under- and oversupply of energy (MUMU) on thermogenesis and efficiency of energy utilization in comparison to a constant maintenance supply (NNNN). Each treatment sequence was assigned to each animal according to a change-over design over 8 weeks. Before and after the treatment periods all the animals were fed at maintenance level (N). Energy deficiency (M) was performed by use of a basal diet with 45% of maintenance energy requirements and values for all the other nutrients sufficient for requirements. Normal (N) and excessive (U) intakes of energy was provided with supplements of starch. The total inake of gross energy during the periods MUMU was exactly the same as during NNNN. Complete energy balances were performed for each animal and period as well as during the pre- and post-experimental phase. There was no or little response of altered energy intake on carbon and energy excretion in faeces, urine and methane. However, heat production was significantly decreased by 4.1% on energy deficiency, and increased by 15.1% during energy oversupply. Summed up over the total sequence the animals produced 5.4% more heat on MUMU than during NNNN. This response was associated with a mobilization of 1.1 MJ/d tissue energy and a decrease in body weight by 2.0 kg. The efficiency of utilization of ME was 88% with energy undersupply and 75% during overnutrition. Criteria of energy balance did not differ between the pre- and post-treatment periods. It could be demonstrated that the increase in energy expenditure at oversupply was entirely explainable by the so-called obligatory thermogenesis. At the energy deficiency periods the efficiency of energy utilization reflected both energy costs of ingestion and processing of nutrients as well as a slight reduction in metabolic rate. Finally, there were no residual effects of the treatment on the energy expenditure of the animals at the end of the experiment.

Animal Feed↗

PubMed1992

[Hematological parameters, selenium concentration and glutathione peroxidase activities in serum and the liver of rats at different selenium and vitamin E levels].

The aim of the both experiments was to determine whether selenium or selenium/vitamin E supply of rats significantly influences the most important hematological criteria. With experiment 1 the influence of Se deficiency should be determined at two different times of growing. So 36 weaned rats were divided into 2 groups of 18 animals each, the half of them being decapitated at day 22, the rest on day 45. In experiment 2 with the aim to investigate a combination of deficient, adequate and excessive Se and vitamin E supply 90 weaned rats in 9 groups were decapitated at day 44. The basic diet contained 0.04 mg Se and 8 mg vitamin E per kg dry matter and was supplemented in exp. 1 with 0 mg or 0.2 mg Se and 30 mg vitamin E and in exp. 2 with 0 mg, 0.2 mg or 1.0 mg Se and 0 mg, 30 mg or 200 mg vitamin E. With Se deficiency Se concentration and GSH-Px activity in serum and liver were significantly reduced. With excessive Se supply Se concentration in serum was higher; there was no effect on GSH-Px activity. Vitamin E supply had no influence neither on Se content nor on GSH-Px activity in serum or in liver. In exp. 1 Se deficiency caused no clear changes of the analysed hematological criteria although the increase of MCV (+3%) and hematocrit (+7%) on day 22 and the increase of leucocytes (+43%) and the decrease of MCH (-3%) and MCHC (-6%) on day 45 were statistically significant. In exp. 2 these results could not be repeated. The vitamin E supply was without significant effects on the examined hematological parameters.

Animals↗

PubMed1992

Absorption, endogenous excretion, and balance of zinc in growing rats on diets with various sugars replacing starch.

The effect of partially replacing starch for various sugars on the apparent and true absorption, endogenous excretion, and balance of zinc was investigated in a study with growing rats. Six groups of five or six animals with an initial live weight of 39.4 +/- 2.7 g were fed diets that had the same Zn content (22 mg/kg), but differed in the sugar content: 1. Starch only (56%); 2. Glucose (15%); 3. Fructose (15%); 4. Sucrose (30%); 5. Galactose (15%); and 6. Lactose (30%). At the start of a 15-d fecal and urinary collection period, each animal was given an intramuscular injection of 380 kBq 65Zn for estimating endogenous Zn excretion by isotope dilution. The ratio of the specific activity of fecal Zn (after 12 d) to that of urinary Zn (after 9 d) was applied to reflect the ratio of endogenous to total fecal Zn collected from day 10 to 15. This ratio averaged 0.59, without significant differences among treatments. For this period, apparent and true absorption averaged 87.1 and 94.7% of Zn intake, respectively, and did not significantly differ among diets. Urinary excretion of 65Zn and of stable zinc by the galactose-fed rats was markedly higher than that by the other animals. Their Zn balance was, per unit weight gain, comparable with that of the other groups (30.7 vs 28.2 to 30.2 micrograms/g).

Absorption↗

PubMed1992

[Concentrations of metabolites and hormones in the blood plasma of lactating dairy cows during treatment with recombinant bovine somatotropin (BST)].

Sixteen lactating dairy cows were submitted to six injections in a four-week interval of either 640 mg prolonged release bST or of 640 mg saline (control, n = 8). The bST-treated animals were pair fed to the control cows, which were fed according to requirements. Fourteen days after each injection, blood samples were derived and analysed for metabolites and hormones. Plasma contents averaged 0.16 mmol/l non esterified fatty acids (NEFA), 2.69 mmol/l glucose, 0.43 mmol/l beta-hydroxybutyrate, 0.024 mmol/l acetoacetate, 78.8 g/l protein, 4.6 mmol/l urea, 0.81 micrograms/l insulin, 44.4 ng/l thyroxine (T4) and 1.41 ng/l triiodothyronine (T3). The bST-application was without effect on the analysed plasma contents.

3-Hydroxybutyric Acid↗

PubMed1992

[Effect of various unsaturated fatty acids on the stability of the erythrocyte membrane in the rat].

In rats restrictive feeding of a half-synthetic diet, with coconut fat as the dietary fat, caused an essential fatty acid deficiency with increased osmotic fragility of erythrocytes against hypotonic saline solutions. A 60% replacement of the coconut fat in the basal diet by pure oleic acid (18:1 n-9) or linoleic acid (18:2 n-6) by 0.6% alpha-linolenic acid (18:3 n-3), eicosatrienoic acid (20:3 n-3) or eicosapentaenoic acid (20:5 n-3) led, in the case of linoleic acid and eicosapentaenoic acid, to a significant decrease in the fragility of rat erythrocytes in comparison with the basal diet. The inefficacy of the alpha-linolenic acid treatment is possibly the consequence of a too low dietary supplementation.

8,11,14-Eicosatrienoic Acid↗

PubMed1992

Concentration of free calcium in erythrocytes and liver mitochondria of zinc-depleted rats.

The concentration of Ca(2+)-ions in mitochondria and erythrocytes of zinc-depleted rats was determined with the fluorescent Ca(2+)-indicator fura-2. The zinc-concentration of the diet did not affect the mitochondrial Ca(2+)-concentration. There was an elevation of 5% for the Ca(2+)-concentration in erythrocytes of zinc-depleted and pair-fed rats compared to ad libitum-fed animals. The cause of this elevation could be ATP-depletion because of restricted food intake.

Animals↗

PubMed1992

Dose-response relationships of alimentary PtCl2 and PtCl4 in growing rats.

In experiments with rats dose-response relationships of alimentary PtCl2 and PtCl4 were investigated. 2 x 81 animals weighing 35 g were randomly distributed among 9 treatment groups which were fed ad libitum with a synthetic diet containing various amounts of Pt during 4 weeks. Pt was added in the form of PtCl2 or PtCl4 in the amounts 0; 0.01; 0.05; 0.10; 0.50; 1.0; 5.0; 10 and 50 mg/kg diet. The Pt supplementation had no influence on life mass gain or food consumption. In the case of 50 mg/kg Pt in the form of PtCl4 the erythrocyte count and hematocrit were reduced by about 13% in comparison with the control group. Dependent on the Pt dose, the application of PtCl4 and PtCl2 induced Pt retention in nearly all tissues especially in kidney. The effects were greater with PtCl4 than with PtCl2. As a result of the higher Pt retention in the kidneys, the serum creatinine was increased for the higher doses of PtCl4.

Animals↗

PubMed1992

Excretion and distribution of injected radiozinc in rats as influenced by the type of carbohydrate.

The aim of this study was to investigate the effect of different dietary sugars on Zn status by measuring the excretion and body distribution of intramuscularly injected zinc-65 in growing rats. Thirty-two weanling rats (39.4 +/- 2.7 g) were allotted to six diets in which starch (56%) was partially substituted for glucose (15%), fructose (15%), sucrose (30%), galactose (15%) or lactose (30%). Diets uniformly supplied 22 mg/kg (dry matter) of Zn. Three days after the start of the dietary regimen each rat was injected with 40 micrograms Zn, labelled with 380 kBq 65Zn, in saline solution. Feces and urine were collected for 15 days; thereafter 65Zn distribution in the liver, pancreas, kidneys, gastrointestinal tract and residual carcass was assessed. Fecal 65Zn excretion was not significantly influenced by the diets, although the gastrointestinal tract of the galactose- and lactose-fed animals contained more 65Zn than did those fed the other diets. 65Zn in the urine and kidneys of the galactose-fed rats was markedly increased as compared with the other groups. Dietary carbohydrate source did not materially affect concentrations of stable zinc in the liver, kidneys, pancreas and residual carcass.

Animals↗

PubMed1991

[The effect of dietary fats on the hemolysis resistance of the erythrocyte membrane during alimentary zinc and calcium deficiency in rats].

In an earlier Zn-deficiency experiment (8) pair-fed-control rats surprisingly showed a 100% increased osmotic fragility of erythrocytes against hypotonic sodium chloride solutions. Because coconut fat, which is very low in essential fatty acids, was used, a deficiency of essential fatty acids was assumed. When the experiment was repeated the diet's coconut fat was replaced by sunflower oil (21% oleic acid, 69% linoleic acid). The erythrocytes of the animals with Zn-deficiency showed an increase in osmotic fragility as against the control groups fed ad libitum. The data of the pair-fed control animals was in between those two groups and did not differ from the other two groups. Using sunflower oil instead of coconut fat decreased the osmotic fragility of the pair-fed animal's erythrocytes in opposition to the preceding experiment up to 100%. Additional Ca deficiency increased the osmotic fragility of the erythrocytes significantly in all three groups. When the Zn and Ca deficiency animals were repleted over 5 days on the basic diet the osmotic fragility of the erythrocytes was decreased significantly. The results show that the use of coconut fat in a restrictive diet causes essential fatty-acid deficiency. It ist also shown that the osmotic fragility of the erythrocytes depends partially on the status of Zn in dietary fat as well.

Animals↗

PubMed1991

[Digestibility, intestinal passage time and energy value of wheat bran in model studies in sows].

An energy metabolism trial was conducted with four sows allocated to each of four levels of wheat bran (7, 14, 21 or 28 g/kg body weight 0.75.day). During 2-week experimental periods half the number of animals received increasing levels of the wheat bran supplementation, the other sows were fed in decreasing order. The basal diet was given constantly at a level of 36 g/kg Bw 0.75. Total digestibility of energy was determined by the collection method. For partioning the digestible energy into a prececal and postileal component the diet was supplemented with 0.3% Cr2O3, and samples of digesta taken by means of a cecum cannula were analyzed for this marker. The rate of passage of food was evaluated by using plastic pellets fed orally as well as inserted into the cecum. During each experimental period a complete energy balance was performed according to the methods of indirect calorimetry. The digestibility and metabolizability of wheat bran energy over the total alimentary tract was 60% and 57%, respectively. As a percentage of the total digestible energy, 70% were found in the prececal site of the digestive tract, and 30% in the hindgut fermentation. The efficiency of utilization of metabolizable energy (ME) for energy retention was 66.2%. Utilization of hindgut energy was lower by about a quarter than utilization of energy digested in the small intestine. The mean contents of ME of wheat bran amounted to 10.1 kJ/g dry matter. The ME of the wheat bran fiber (non-starch poly-saccharides) was calculated to be 5 kJ/g. The excretion of short-chain fatty acids in the feces was only 1-2% of fecal energy. The rate of passage of food decreased from 78 h (basal diet alone) to 52 h with the highest wheat bran supplementation. The prececal retention time was only 20% of the total rate of passage through the alimentary tract.

Animals↗