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Biomedical subjects

M Kirchgessner

Publications and source records attributed to M Kirchgessner.

At least 163 records · Page 9Linked to original sources
PubMed1984

[Energy metabolism in fasting and subsequent refeeding].

A metabolism trial with six adult sows was conducted to study the effect of fasting and realimentation on heat production, energy retention, and utilization of energy. Complete balance measurements by indirect calorimetry (CN-method, RQ-method) were carried out from the 8th to the 10th day of fasting, and thereafter from the 1st to the 7th day and from the 33rd to the 36th day of the realimentation phase. Previous to fasting and during the time of refeeding the energy supply was adapted to maintenance requirement. Heat production rose by 20% after refeeding the animals. This heat increment corresponded to 2.2 MJ/kg feed dry matter, or 12% of the energy intake, respectively. The stimulation of heat production induced by refeeding occurred spontaneously within one day. After the first day of refeeding a plateau was reached, which in the course of the steady energy supply was still present even after the 5th week of realimentation. Residual effects of fasting in the mode of a compensatory heat production were not observed. Therefore, a constant utilization of efficiency of metabolizable energy for maintenance was estimated at 82%. The change of body energy during the entire experimental period resulted in a loss of 198 MJ corresponding to about 5% of the body weight.

Animals↗
PubMed1984

[Fe and Cu content in bones, muscles and whole body of growing rats with different Fe and Cu supplies].

The Fe and Cu contents in the femur and in the skeleton muscle were investigated in a trial series with factorial Fe and Cu supplies of growing rats (0, 25, 250, and 625 micrograms of Fe supply; 0, 10, 100, and 250 micrograms Cu supply per g of the diet). In addition, the reaction of the carcass to the different trace element supply was compared to the changes of the Fe and Cu contents in organs and tissues. In the femur, the Fe contents clearly increase in all grades of the Cu supply with increasing Fe supply. But because of the reduced live weight of the trial animals without Fe supply, this is valid only from 25 micrograms Fe/g diet on. For all Fe levels, the influence of the Cu supply on the concentration and the content of Cu results in a plateau in the range of 10-100 micrograms Cu/g diet; it is not reached with Cu deficiency and exceeded with an excessive Cu supply (250 micrograms/g). A clear increase of the Fe concentration in the muscle occurs only at a supply of 250 micrograms Fe/g diet. A further increase at 625 micrograms Fe/g only occurs at a Cu supply of 250 micrograms/g. Generally, the Fe concentration is reduced in the Cu deficiency. The Cu concentration in the muscle increases in all cases with the Cu supply, and the extent of this increase is strongly influenced by the Fe supply. The Fe contents in the carcass primarily depend on the Fe dosage. For the total contents of copper there are hints of a homeostatical regulation in the range of 10-100 micrograms Cu/g, but it seems to be disturbed if the Fe supply (0 or 25 micrograms/g) is insufficient. The comparison of the Fe and Cu contents in organs and tissues to those in the carcass shows that the reactions to the different supply levels, which are clearly different in the tissues, can be reproduced but insufficiently by the trace element analysis in the carcass.

Aging↗
PubMed1984

[Effect of protein restriction and refeeding on the nitrogen balance in piglets].

In balance trials the effect of a 50% protein restriction with subsequent realimentation on N balance, endogenous N excretion, digestible and metabolisable energy was tested using 36 piglets. The dietary protein content during the restriction period from 5-12 kg live weight was 22.9 (control) and 12.4% of the dry matter and during the realimentation period from 12-18 kg live weight in both groups 17.2%. Protein quality and energy supply were not changed between the groups. Restricted protein supply proportionally reduced N retention with slightly improved efficiency of digestible N from 67 to 70%. During realimentation the previously reduced N supply did not influence N retention but increased the apparent N digestibility by 2% units. The endogenous N losses as well as digestible and metabolisable energy were not different between the groups. It was concluded that compensatory responses of the N metabolism might require a stronger dietary restriction and respectively or a longer restriction period.

Animals↗
PubMed1984

[Content of essential amino acids in prematurely weaned piglets after a qualitatively and quantitatively variable protein diet].

A total of 60 piglets of German Landrace weaned at the age of 2 weeks were fed ad libitum with isoenergetic diets of different proteins (casein + dried skim milk, soybean protein + dried skim milk, only soybean protein) and different protein levels in the diet (20, 27, 34, 40% in D.M.). After 4 weeks the piglets were homogenized and examined for their content of essential amino acids in the whole body mass by ion exchange chromatography. On the fresh and dried material the contents of Thr, Val, Ile, Leu, Lys and Ser increased both with higher supply of protein and milk instead of soybean protein in the diet. The contents of Phe and Arg were only insignificantly changed by protein quality. Referred to the concentration of Met and Cys there were found higher standard deviations and interactions between protein supply and quality. The content of essential amino acids also was influenced by the protein quality of the diet, when related to the whole body protein. On the other hand a significant effect of increasing protein supply only took place if soybean protein was the single protein ingredient of the diet. Related to Lys the contents of Thr and Cys nearly were constant, whereas the amino acid/lysine proportion in the case of Met, Ile and Arg changed considerably.

Amino Acids, Essential↗
PubMed1984

[Nutrient digestibility and nitrogen utilization in lactating cows under restricted protein supply and subsequent refeeding].

The effects of a 17% deficiency of crude protein for four weeks on nutrient digestibility and parameters of N metabolism were investigated using four pairs of monozygotic twin cows. During a period of realimentation of three weeks with slight nutrient oversupply and a further period of three weeks with nutrient supply adjusted to the lactation trend it was examined if residual effects remain. Protein restriction enhanced the excretion of fecal dry matter by 7.7%. Total fecal nitrogen was a high in the restricted group as in the control group. Apparent digestion coefficients for dry matter, organic matter and N-free extracts were lowered by 2 to 3 percent points with deficient protein nutrition. Crude fiber and nitrogen digestibilities declined by 4.5 and 9.8 percent points, respectively. The reduction of urine nitrogen excretion amounted to 47% as consequence of a drastically diminished nitrogen content of urine. Total nitrogen retention (milk-N and body-N) was lowered by 14%. The sum of the relative nitrogen losses via faeces and urine was not different between the protein-deficient and the normal diet. The utilization of feed nitrogen for milk nitrogen excretion was 28.2% in protein deficiency and 25.9% in control feeding. After realimentation no relevant residual effects of the previous protein deficiency were found neither with respect to nutrient digestibility nor to parameters of the nitrogen balance. So far the observed permanent effect in reduced milk yield by 6% of the expected performance can not be explained with changes in digestibility or nitrogen balance.

Animals↗
PubMed1984

[Thermogenesis from the breakdown of a ketogenic diet in an experimental model using swine].

A respiration calorimetry experiment with 10 matures sows was conducted to study the effect of a ketogenic diet on heat production and energy utilization. The ketogenic diet contained no carbohydrates and 85% of its energy as fat. The control diet was a mixed diet with most of its energy as carbohydrates. Both diets provided the same daily protein intake, which was slightly below the calculated protein requirement. The level of energy intake was adjusted to a moderate positive energy balance. Both diets were allocated to the same animal for three weeks each according to a crossover design. Seven-day collection periods and 48-hours measurements of the gaseous exchange (carbon-nitrogen balance method) were conducted on individual sows per diet. The ketogenic diet substantially increased the energy losses in faeces, which resulted in a energy digestibility of 75% compared to 93% with the mixed diet. The methane production was also significantly depressed. In contrast, the urine energy excretion was not influenced by the extremely high fat diet. The nitrogen balance showed lower faecal nitrogen losses and a higher urine nitrogen excretion in the animals with the high fat diet. Because of this compensative response no difference in nitrogen retention was observed between the two dietary treatments. The ketogenic diet caused no detrimental effects on thermogenesis or energy utilization. The results of both criteria could be fully explained by the well accepted ideas of the efficiency of utilization of the energy from fat under balanced nutrition conditions. Overall the results demonstrate that a high fat diet has no regulatory effect on the usually diet-induced thermogenesis.

Animal Feed↗
PubMed1983

[Iron levels of muscle after various iron and protein intakes].

In a 2 X 3 factorial experiment with growing rats (starting weight 32 g) the Fe content (5, 25, 625 mg/kg) and the protein content (5, 25, 45%) of the diet was varied. The diets were fed ad libitum for 35 days. At the end of the experiment the animals were sacrificed. The iron content was determined in a defined sample of musculus supraspinalis after dry ashing with AAS. An insufficient protein supply produced an overall increased iron content and a reduced muscle mass. A deficient iron supply caused a lowered iron content in the muscle in the case of sufficient and excessive protein content of the diet. On the other hand an iron supply exceeding the requirement did not lead to higher iron contents.

Animals↗
PubMed1983

[Influence of picolinic acid and citric acid on intestinal absorption of zinc in vitro and in vivo].

The influence of the ligands picolinic acid and citric acid on the intestinal absorption of zinc was studied in two different experimental trials with Zn-depleted and Zn-supplied pair-fed rats using everted sacs in vitro and the ligated small intestine in vivo. ZnSO4 was applied in water solution (pH 5.8) without ligands or together with picolinic acid at a molar ratio of 1:0.2, 1:2, and 1:20 or together with citric acid at a molar ratio of 1:1, 1:10, and 1:100. The intestinal Zn transfer of the Zn-depleted rats with picolinic acid is significantly increased only at a molar ratio of 1:20 (zinc:ligand) (P less than 0.001). The other in vitro results of Zn absorption were only slightly improved, mainly at the high molar excess of picolinic acid in comparison to ZnSO4 without ligands. Only a tendency for an increased Zn transfer--however, already at a narrow molar ratio of 1:1 or 1:10--could be seen when citric acid was added. The intestinal uptake was not influenced by citric acid. The absorption of zinc in vivo did not vary in dependence of the addition of picolinic or citric acid in different molar ratio in comparison to ZnSO4 addition without ligands. Zn-depleted rats showed a significantly higher Zn absorption rate than Zn supplied pair-fed rats independently of the kind of ligand and the zinc:ligand ratio (P less than 0.001). These results are discussed in detail.

Animals↗
PubMed1983

[Growth and hematological criteria of rats by different protein and iron supply].

In a two-factorial experiment with growing rats, protein content of diet (5, 25, 45%) and Fe supply (5, 25, 625 mg/kg diet) were changed. Both factors as well as their interactions influenced growth (p less than 0.001). The growth was reduced especially by deficient protein supply but although by inadequate iron supply and in a smaller degree by an excessive protein content of the diet. Hematological values as hemoglobin content, counts and volume of erythrocytes, hematocrit, MCH and MCHC - measured after 35 days of the experiment - were influenced by both factors and their interactions, too (p less than 0.001). Again deficient protein supply and insufficient Fe supply have the marked effects. Referring life weight as well as hematological parameters, the deficient protein supply was - independent of Fe supplementation - the limited factor, whereas in the cause of higher protein content (25, 45%) an insufficient Fe supply has negative effects.

Animals↗
PubMed1983

[Effect of different concentrations of various zinc complexes (picolinate, citrate, 8-hydroxyquinolate) in comparison with sulfate on zinc supply status in rats].

12 groups of 8 young male Sprague-Dawley rats received a semisynthetic casein-diet, whose zinc concentration (1.3 ppm) was adjusted to 5, 10 and 15 ppm by supplementation of various Zn complexes or salts like Zn citrate, Zn picolinate, Zn 8-hydroxyquinolate and Zn sulfate. After 24 days all animals were killed and examined on parameters of zinc supply status. The weight gain of the animals with 5 ppm dietary zinc was strongly reduced compared to groups with the higher dietary zinc content. The type of the supplemented Zn compound showed in no way an influence on the live-weight of the animals. The zinc concentration of the tissues, too, was only dependent on the level of the dietary zinc concentration and not on the type of supplemented zinc compound. The activity of the alkaline phosphatase in serum, a zinc metalloenzyme, was altogether reduced in the zinc-deficient animals with 5 ppm dietary zinc content, but showed a significant higher activity in the citrate and 8-hydroxyquinolate group than in the sulfate and picolinate group. Also the percent zinc-binding capacity of serum, a good indicator for estimating the zinc supply status of rats, showed a better zinc supply of the citrate group with 5 as well as 10 ppm dietary zinc, compared with the other groups on the same dietary zinc content. The serum zinc concentration of rats with 5 ppm as Zn citrate was more than twice higher than in animals given zinc as picolinate, 8-hydroxyquinolate or sulfate. The results indicate a better utilization of zinc chelated by citric acid than by picolinic acid, 8-hydroxyquinoline or as salt like sulfate. But the higher bioavailability of zinc in human milk should not only be attributed to the presence of citrate.

Alkaline Phosphatase↗
PubMed1983

[Palatinit--digestibility and energy utilization in model experiments with sows].

A respiration trial with 12 adult sows was conducted as a balanced incomplete block design to study the effect of Palatinit on energy and nitrogen balance. The treatments were the basal diet fed at maintenance level alone or with the addition of sucrose and Palatinit, respectively. The apparent digestibility of the energy of Palatinit was 91.0%, whereas sucrose was completely digested. The fecal excretion of nitrogen after feeding of Palatinit increased about 50% as compared to the group's basal diet and basal diet plus sucrose. The urine energy excretion and the methane losses amounted to 1% of the ingested energy of Palatinit. The efficiency of utilization of metabolizable energy was 68.9% for Palatinit and 75.3% for sucrose. Altogether, the results show that 62% of the Palatinit energy and 74.5% of the sucrose energy were retained as body energy.

Animals↗
PubMed1983

[Iron concentration in various organs of rats following administration of various iron and protein loads].

In a 2 X 3 factorial experiment with growing rats the diet varied for the iron content (5, 25, 625 ppm) and for the protein content (5, 25, 45%). The diets were fed ad libitum for 35 days. At the end of the experiment the iron content of different organs was determined. Both experimental factors and their interactions influenced the iron concentration as well as fresh weight and dry matter dependent on organ. Especially the influence of deficient protein supply and of insufficient iron supply was very marked. Dependent on the iron supply there are different responses between storage and functional compounds of iron.

Animals↗