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L Hoffmann

Publications and source records attributed to L Hoffmann.

At least 73 records · Page 4Linked to original sources
PubMed1992

Comparison of energy deposition and utilization of feedstuffs and rations between growing and adult pigs.

The effect of energy deposition and the utilization of feedstuffs and rations were compared between growing and adult pigs. The good agreement in the data leads to the conclusion, that the energy deposition effect of feedstuffs and rations in growing pigs can be estimated with an equation based on measurements in adult pigs. Exceptions are feedstuffs which are digested bacterially to a relatively high part in the large intestine, as e.g. sugar beet pulp, raw potatoes or similar feed.

Aging↗
PubMed1992

[The energetic utilization of rations with steamed potatoes in growing swine].

The energetic utilization of rations with steamed potatoes (40 and 50% of DM of ration) was measured in 8 growing pigs, live weight 30-70 kg by means of respiration experimental techniques. The experiments were carried out using the difference method (3 periods feeding basal diet and 3 periods feeding basal diet plus potatoes). The digestibility of energy of the steamed potatoes amounted to 94%, that of organic substances 96% and that of crude protein 77%. The metabolizable energy amounted to 16.1 and the energy deposition to 12.0 MJ/kg DM of steamed potatoes, 74.5% utilization respectively. The results in growing pigs are very similar to the results in adult pigs.

Animal Feed↗
PubMed1991

[Energy metabolism of growing rats in relation to the environmental temperature].

8 experiments were carried out with 9 albino rats each (Wistar line, bred at the institute) in the live weight range between 70 and 200 g and at environmental temperatures (ET) of 34, 32, 30, 28, 26, 24, 22 and 20 degrees C. In the course of each individual experiment the rats were alternatively fed for maintenance and weight gain (semi ad libitum) with feed mixtures containing 10, 25 and 40% crude protein (3 animals/variant). Energy metabolism was measured according to the method of indirect calorimetry over a total of 780 metabolism periods. In the temperature range studied there was no compensation between thermoregulatory heat and heat from other processes of the metabolism. The partial utilization of metabolizable energy for energy retention in the body was independent of ET and ranged between 73 and 80% for the 7 experiments with ET between 32 and 20 degrees C. Energy utilization depended on the protein content of the feed and decreased from 81 to 79 or 73 resp. when the protein content increased from 10 to 25% or to 40% resp. Energy requirement for protein retention varied between 1.61 and 2.09 kJ metabolizable energy/kJ and was independent of ET. Energy maintenance requirement (measured at 28, 30 and 32 degrees C) increased with the growing protein content from 415 to 439 and 447 kJ/kg LW0.75.d resp. (regression analysis) and from 411 to 420 and 432 kJ/kg LW0.75.d (measuring at maintenance level). The relative weight gain with the increased protein content of the feed largely corresponds to the expected values according to the efficiency of ATP synthesis in the oxidative degradation of nutrients. The relationship between heat production and ET is parabolic. In the live weight range studied the average thermoneutral temperature (TNT) was 32 degrees C. It decreased during the course of development from 34 to 30 degrees C. TNT decreased with the growing protein content of the feed. Thermoregulatory heat production depended on both environmental temperature and the stage of development. Its average value in the development range studied decreased with an increase of the environmental temperature by 2 K each, starting from 20 degrees C and rising to 32 degrees C, in the following linear sequence: 23.3, 21.0, 16.8, 12.5, 8.3, 4.0 and 0.3 kJ/kg LW0.75.d.K.

Animal Feed↗
PubMed1991

[The energetic utilization of sugar beets, dried chips, cane sugar and apple pectin by growing swine. 2. Nitrogen and energy metabolism].

The energetic utilization of rations with raw and steamed sugar beets, dried sugar beet pulp (16 measured values each), sucrose and apple pectin (8 measured values each) as supplement feed to a basic ration was measured at 4 growing pigs each in the live weight range of between 40 and 130 kg. The utilization of the energy in the rations amounted to 69.1 +/- 5.5, 68.3 +/- 7.1, 60.9 +/- 5.8, 70.5 +/- 4.1 and 69.9 +/- 6.9% (same sequence as above). The utilization values for the supplemented feedstuffs were 69.2 +/- 7.4, 68.0 +/- 10.0, 55.9 +/- 9.7, 72.2 +/- 7.6 and 71.7 +/- 17.3%. The average retention value of the digestible pectin was derived from the test results with dried sugar beet pulp and apple pectin as 5.8 kJ/g. An influence of the ontogenetic development on energy utilization cannot be derived from the comparison of the retention effect of digestible nutrients measured at growing pigs and that derived from adult pigs.

Animal Feed↗
PubMed1991

[The energetic utilization of rations with dried concentrates, potatoes, sugar beets, apple pectin and cane sugar by growing, intact and ileorectostomized swine. 2. Comparison of results].

Results of the measuring of the total metabolism of growing intact pigs (INT) and pigs with ileorectal anastomoses (IRA) are compared. The 16 comparisons are based on studies with rations of dried feedstuffs and rations containing between 30 and 50% of the DM raw or steamed potatoes and sugar beets, sucrose and apple pectin. On an average of all comparisons the relative values for the digestibility of energy, DM and the organic matter as well as for the metabolizability of the energy were between 81 and 82% (values measured at INT animals = 100). The comparison also refers to the crude nutrients, the water-soluble carbohydrates, the starch and the pectin. As a tendency, the IRA utilized the metabolizable energy better than the INT animals. The energy maintenance requirement of the IRA animals was--by 15%--significantly higher than that of the INT animals. There is not yet an answer to the question in how far comparative studies of INT and IRA animals make verified statements with regard to the differences in the energetic utilization of the precaecally and postileally digested nutrients possible. For this, further experiments will be necessary.

Anastomosis, Surgical↗
PubMed1991

[Energy metabolism of growing broilers in relation to the environmental temperature].

7 experiments with 6 chickens each (origin Tetra B) in the live weight range between greater than 100 and less than 300 g and up to 1800 g were carried out at environmental temperatures (ET) of 35, 30, 25 (2 experiments) 20 (2 experiments) and 15 degrees C. In the course of each experiment the chickens alternatively received feed mixtures containing 20 and 40% crude protein (3 animals/variant) for maintenance and weight gain (semi ad libitum). Energy metabolism was measured according to indirect calorimetry over a total of 645 metabolism periods. In the temperature range studied there was no compensation between thermoregulatory heat and heat from other metabolic processes. The partial utilization of metabolizable energy for energy retention in the body was independent of ET and remained in the limits between 71 and 73%. Energy utilization was dependent on the protein content of the feed. It decreased from 75 to 69% with the increase of the protein content from 20 to 40%. Energy requirement for protein retention varied between 1.67 and 1.89 kJ metabolizable energy/kJ and was independent of ET. Energy requirement (metabolizable energy) for the maintenance of the energy balance was independent of the protein content of the feed. It increased from 433 kJ/kg LW0.75.d at 35 degrees C to 693 kJ/kg LW0.75.d at 15 degrees C ET. The relationship between heat production and ET is parabolic. The thermoneutral temperature decreased from 35 to 25 degrees C in the course of development. In the live weight range of 300-500 g thermoregulatory heat production had its maximum with 19 kJ/kg LW0.75.d.K and decreased in the further development to 10-13 kJ/kg LW0.75.d.K.

Animal Feed↗
PubMed1991

[Energy metabolism of growing broiler chickens kept in groups in relation to the environmental temperature. 1. Feed intake, heat production and energy utilization].

In 5 experiments with young broiler chickens kept in groups at environmental temperatures (ET) of 35, 30, 25, 20 and 15 degrees C feed intake, live weight development and heat production were ascertained between their 5th and 57th days of life. Feed intake and live weight were ascertained separately according to sex. With live weight being the same, feed intake increased with decreasing ET. There was no maximum feed intake up to the 57th day of life at between 20 and 25 degrees C. At the end of their 57th day of life the male and the female chickens had achieved the following live weights (in the sequence of decreasing ET 35-15 degrees C): 1342; 2014; 2829; 2946; 2374 and 1367; 1900; 2512; 2496 and 2200 g/animal resp. The highest live weight gain of the chickens was achieved at between 25 and 20 degrees C with 60-70 g/d for male and with 50-60 g/d for female animals. Heat production (HP) increased progressively with age. The highest HP was registered at 20 degrees C ET.

Age Factors↗
PubMed1991

[Energy metabolism of growing broiler chickens kept in groups in relation to the environmental temperature. 2. Heat production, thermoregulatory heat production and thermoneutral temperature (short term measurement)].

In 5 experiments the weekly rhythm of the heat production of growing young broiler chickens kept in groups between their 5th and 57th days of life was measured according to the method of short-time measuring (30-minute measuring periods) in dependence on environmental temperature (ET) between 40 and 5 degrees C in stages of 5 K by means of gas exchange and indirect calorimetry. The keeping temperature ranged from one experiment to the other from 35, 30, 25, 20 to 15 degrees C. The dependence of heat production on ET is parabolic in the medium and high ranges of temperature. As a rule, heat production increases progressively with very low ET. Thermoneutral temperature depends on both, the age (live weight) of the chickens and environmental temperature. Thermoregulatory heat production decreases with growing age. It changed from 24 kJ/kg LW0.75.d.K at the beginning to 8 kJ/kg LW0.75.d.K at the end of the experiments.

Age Factors↗
PubMed1991

[Energy metabolism of growing broiler chickens kept in groups in relation to the environmental temperature. 3. Moderated model description of the efficiency of the utilization of variable energy for body energy retention].

An attempt is made on the basis of extensive studies on the energy metabolism of growing broilers to describe as a model the efficiency of the energetic utilization of the feed. The following parameters are components of the model: metabolizable energy, energy maintenance requirement, thermoneutral temperature, thermoregulatory heat production, heat production from the partial utilization of metabolizable energy for body energy retention, heat production (total), energy retention, utilization of metabolizable energy (total), live weight, environmental temperature. At environmental temperatures of 35, 30, 25, 20 and 15 degrees C resp. the model statement for the total utilization of metabolizable energy amounts to 32.4, 39.4, 39.6, 37.3 and 36.2% resp.

Animal Feed↗
PubMed1991

[The energy metabolism of growing swine in the liveweight range of 10-50 kg. I. Study design, feed intake and digestibility].

Studies of the energy metabolism at maintenance and growth levels after the feeding of rations with a crude protein content of 17-24% and 44-47% resp. were carried out with hybrid pigs of line 150 in the live weight range between 10 and approximately 50 kg. This paper gives information on the methods and the outlay of the experiment and presents results concerning feed intake, live weight development and digestibility. Feed intake increased on average with growing live weight by 30-35 g DM/kg live weight. Feed conversion ranged from 1.2 to 1.8 kg DM/kg live weight gain in the first period and from 2.3 to 3.2 kg DM/kg live weight gain in the last period. The digestibility of the energy in the rations with a crude protein content of between 17 and 24% averaged 80% and that of the rations with a crude protein content of 44-47% averaged 86%. In the course of ontogenetic development the digestibility increased up to about 30 kg LW. The influence of the nutritional level on the level of digestibility was unequal in the experiments. In one experiment a decrease (1% unit) and in two experiments an increase (1-3% units) of the digestibility after the feeding of growth level in contrast to maintenance level could be observed. The change of rations with a varying protein content did not result in an influence on the digestibility level in comparison with the constant feeding of one ration.

Absorption↗
PubMed1991

[Determination of kinetic parameters of protein metabolism in growing rats in conjunction with measurement of energy metabolism. 1. Determination of kinetic parameters of protein metabolism in relation to body weight and protein content of the feed].

The digestibility, the N balance, the rate of protein synthesis and other parameters, characterising the protein metabolism in dependence on live weight, protein- and energy supply are estimated on Wistar rats (4-5 animals/group). These experiments were done in 5 alternating consecutive growth and energy maintenance periods at 4 different levels of protein (6, 10, 17, 26% CP) during the live weight period of 70 to 230 g. The rate of protein synthesis was calculated from the course of renale 15N excretion by means of the end product method after giving a single dose of a mixture of 17 15N labelled amino acids. N deposition, rate of protein synthesis and flux rate increased with the protein level of the ration. During maintenance these data were much lower, but showed the same dependence on the protein level. The absolute protein synthesis (g/d) increased up to the live weight of 130... 180 g and decreased afterwards according to the age. The reutilization rate varied between 44 and 87% and decreased with increasing dietary protein level by 27% and during proceeding age by 8 ... 12%. In contrast to the absolute metabolism rates (g/d) the fractional rates (%/d) clearly decreased with the age of the animals. The stimulation of these rates by the dietary protein level resembled that for the absolute rates of synthesis. The protein deposition showed the typical course of a growing curve according to the N intake and the protein synthesis showed practically the same course but on a higher level. The break down remained constantly (approximately 140 mg N/d) up to an N intake of about 360 mg and afterwards it increased too.

Amino Acids↗
PubMed1991

[Determination of kinetic parameters of protein metabolism in growing rats in conjunction with the measurement of energy metabolism. 2. Determination of the energy requirement for protein retention in conjunction with measurement of the protein synthesis rate at different levels of protein supply].

Energy metabolism-by means of indirect calorimetry-and kinetic parameters of the protein metabolism on the basis of the 3-compartment model were measured with 4 groups of 4 or 5 male Wistar rats in the growth range of between 70 and 230 g live weight in a total of 5 alternately successive periods at the feeding levels growth and energy maintenance as well as 4 different levels of protein supply (6, 10, 17 and 26% crude protein in the feed). The partial energy requirement values for protein retention (bp) for every animal and every period are calculated from the data of energy metabolism. On an average of the 3 growth periods they amounted to 1.75 +/- 0.37 kJ/kJ. A statistically significant linear relation with a slope of approximately 1 could be derived regressively between the protein synthesis rate and the protein retention rate, including all 5 test periods. There was no proven relation between the bp values and the corresponding individual values of the ratio of protein synthesis rate-diminished by the regressively derived protein synthesis rate in the N balance-to the protein retention rate. The results do not permit proven statements on the quantitative relations between protein turnover and energy requirement for protein retention, which is first of all due to methodical shortcomings in measuring both protein metabolism and energy metabolism. They indicate, however, that the heat production from protein synthesis has only a relatively low share in the additional energy expenditure for protein retention and does not considerably surpass the necessary minimal cost for the synthesis of the deposited protein in growing rats.

Animal Feed↗
PubMed1991

[The energy metabolism of growing swine in the body weight range of 10-50 kg. 2. Nitrogen and energy metabolism].

Investigations were carried out about nitrogen and energy metabolism feeding rations with 17-24 and 44-47% crude protein content on maintenance and growing level to castrated male hybrid pigs of line 150. In growing periods the N deposition amounted to 10 g/animal.d (15 kg live weight), 18 g/animal.d (30 kg LW) and 21 g/animal.d (greater than 40 kg LW) on lower protein feeding level. In experiments with higher protein feeding level the corresponding results were 17, 22 and 22 g N deposition/animal.d. The partial utilization of metabolizable energy for deposition amounted to 70% for the rations with 17-24% protein content and to 59% for the rations with 44-47% protein content, without correlation to the animals development and the alternation in the protein feeding level. The results of regression analysis about maintenance requirement were 814, 775 and 806 kJ metabolizable energy/kg LW0.62.d in trials feeding rations with 17-24% crude protein content as well as 764, 846 and 818 kJ metabolizable energy/kg LW0,62.d in trials feeding rations with 44-47% crude protein content. 1,5-1,8 MJ metabolizable energy were used per MJ protein energy deposition and 1,3-1,4 MJ per MJ fat energy deposition respectively. The energy deposition per kg live weight gain amounted to values between 9 (10 kg LW) and 18 MJ (60 kg LW).

Animal Feed↗
PubMed1991

Immunohistochemical detection of renal carbonic anhydrase of patients with recurrent urolithiasis.

In renal exploratory excisions the isoenzyme C of the carbonic anhydrase was detected in 51 operative treated patients with recurrent urolithiasis and in 6 patients with ren mobilis or stenosis of the ureteral pelvic junction by using the immunohistochemical PAP-method. In the distal tubules and collecting ducts there is an alternating occurrence of cells with small and those with strong reactivity. This correlates with the distribution of mean or principal (P-, small reaction) and intercalated (I-, strong reaction) cells. The number of carbonic anhydrase rich cells and the degree of their cytoplasmic reaction to this enzyme seem to correlate with the ability of the urine to acidify. The patients were divided into four groups according to the mean urine pH estimated for a period of two weeks. The third group with predominantly acid urine (pH less than 5.8) showed a significantly increased number of carbonic anhydrase rich cells (mean = 63% +/- 6, n = 18) as compared to the first group (controls) without urolithiasis and normal urine (pH 5.8-6.8, mean = 46% +/- 8, n = 6) or the second group with urolithiasis and normal urine (pH 5.8-6.8, mean = 46% +/- 8, n = 28). The fourth group with predominant alkaline urine (pH greater than 6.8) showed a significantly decreased number of intercalated cells (mean = 42% +/- 16, n = 5) in comparison to the third group. Indeed, the difference with the control group is not significant but the cytoplasmic reaction of I-cells decreases distinctly in comparison to all other groups.

Biopsy↗
PubMed1991

Lonidamine versus high-dose tamoxifen in progressive, advanced renal cell carcinoma: results of an ongoing randomized phase II study.

Sixty patients with metastatic renal cell carcinoma were entered into an ongoing randomized phase II study with lonidamine, 350 mg/m2 orally daily (arm A) and high dose tamoxifen, 150 mg/m2 orally daily for 6 months, afterwards 50 mg/m2 (arm B), until tumor progression. All patients had measurable disease and documented tumor progression prior to treatment. There were 1 complete and 1 partial remission among 19 evaluable patients in arm A (10.5%) and 2 complete and 1 partial remission among 25 evaluable patients (12%) in arm B. Objective responses were observed in pulmonary, nodal, and cutaneous metastases. In addition, in 63% and 64% tumor progression could be stopped in arm A and B, respectively. Median response duration was 100 days (range, 20-361) in arm A and 150 days (range, 28-355) in arm B. One year survival rate was 37.5% with lonidamine and 35% with tamoxifen. In arm A patients with tumor progression within 12 weeks after diagnosis of metastatic disease survived significantly shorter than patients with a longer interval (P less than 0.05). Nephrectomy or number and localization of metastatic sites failed to significantly influence probability of remission or survival. Toxicity was mostly mild to moderate. Four patients in the lonidamine arm had to discontinue treatment because of intolerable myalgias, which were immediately reversible. These data suggest that lonidamine and high-dose tamoxifen are moderately effective in widespread renal cell carcinoma where treatment intention is palliative.

Adult↗
PubMed1990

[Measuring energy turnover in the adult swine during feeding of rations with potato starch, potatoes, beets, pressed shreds and coarse fodder as supplements to a basic ration. 1. Energy turnover and energy utilization].

25 rations with a wide variation of the content of various carbohydrates (crude fibre 36-185; water-soluble carbohydrates 25-306, starch 272-683 g/kg DM) were fed to male castrates (n = 8) of a live weight between 90 and 180 kg, and energy metabolism was measured. The rations were composed of a cereal basic ration and various feed-stuffs (potato starch-raw and soaked) potatoes (raw and steamed), sugar beet and products from it, maize pellets, dried roughage lucerne, clover, lupin, grass, rye straw meal) as supplements. The digestibility and metabolisability of the energy of the rations ranged between 88 and 62 or 86 and 60% resp. Between 2 and 4% of the consumed energy were lost in urine. The partial utilization of the metabolizable energy of the rations varied between 80% (processed supplement of potato starch) and 52% (supplement of rye straw). The rations with supplements of dried roughage were relatively well energetically utilized-between 63 and 70%. A regressively calculated difference of 17%-units was regressively calculated between the utilization of metabolizable energy of either precaecal or postileal origin.

Animal Feed↗
PubMed1990

[Measuring of the energy turnover in adult swine during feeding of rations with potato starch, potatoes, beets, pressed shreds and coarse fodder as supplements to a basic ration. 2. Evaluation and discussion of the results for further development of energetic feed rating for swine].

Energy metabolism measurings of male castrates of a live weight between 90 and 180 kg after feeding rations with a wide variety in the content of various carbohydrates (crude fibre 36-185, water soluble carbohydrates 25-306, starch 272-683 g/kg DM) formed the experimental basis of the considerations. Energy retention depended significantly on the digestibility and metabolizability of the energy, on energy concentration and the crude fibre content of the rations. By means of multiple regression analyses the energetic effect of 1 g digested matter of the carbohydrate fraction was assessed as follows: 12.9 kJ for starch, 12.1 kJ for disaccharides, 11.5 kJ for the remaining water soluble carbohydrates and 10.4 kJ for bacterially fermentable carbohydrates (BFC). There was a difference between the energetic effective value of starch and BFC. This corresponds completely to the difference in the utilization of metabolizable energy between exclusively precaecal and postileal digestion. The following conclusions are drawn for the further development of the energetic feed evaluation for pigs in the framework of the GDR feed evaluation system: --There are to be differentiated fixed values for the retention of digestible carbohydrates for the fractions starch, water soluble carbohydrates (pectin) and bacterially fermentable carbohydrates. --The influence of the digestibility of the energy in the ration on the energetic retention effect of BFC is small. The integration of these variables into an estimation equation for the energetic feed value is therefore not necessary.

Animal Feed↗