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H D Bock

Publications and source records attributed to H D Bock.

At least 19 recordsLinked to original sources
PubMed1988

[Methodologic studies for the measurement of kinetic parameters of the metabolism of whole body protein in association with measurements of energy metabolism in rats].

In 3 successive experiments with growing rats the suitability of pulse labelling with [15N]glycine, linked with a 14C labelling by means of [14C]lysine (experiment 3), was tested for the determination of kinetic parameters of the protein metabolism of the whole body by the application of the compartment model in comparison with pulse labelling with a 15N amino acid mixture (experiment 2) and long-time labelling with 15N with 15N labelled wheat in the feed (experiment 1) under standardized experiment conditions. In simultaneously carried out measurings of energy metabolism with parallel groups of animals the comparability of the metabolic development was studied. The ascertained values of protein synthesis rate, protein catabolism rate and re-utilization rate showed insignificant differences only between the 3 15N tracer variants (with certain limitations for the 'protein turnover' (P)-group of experiment 2) in comparison with errors of the applied methods, from which conclusions can be drawn for the suitability of [15N] glycine as tracer, at least under the experiment conditions tested. The protein synthesis and degradation rates ascertained from 14CO2 excretion in experiment 3 were clearly below those average values ascertained with 15N. The differences in the average heat production between the main periods of the 3 experiments were statistically insignificant.

Animal Feed↗
PubMed1987

[Effect of thermal treatment of potato products on nutrient decomposition in the digestive tract of swine. 1. Passage and digestibility of nutrients in the various portions of the intestine].

In addition to a basic ration (barley, dried green fodder, fishmeal) pigs (castrated males, 100 ... 130 kg live weight) received a supplement of raw potato starch, raw ensiled potatoes, cooked potato starch or steamed ensiled potatoes; nutrient and amino acid passage and digestibility (absorption) were measured in the small intestine, the upper large intestine and the total digestive tract with the help of simple cannulae at the distal ileum and the middle of the hind gut and the estimation of the HCl insoluble ash as an indicator. In addition, the amounts of bacteria in faeces were determined and the influence of raw and cooked potato starch on N retention was ascertained. When raw potato products were fed, distinctly higher amounts of dry matter, organic matter and starch pass the ileum, which get into the colon undigested, i.e. the digestibility of these substances is low at the end of the ileum (raw potato starch 24%, starch of raw ensiled potatoes 36%). Up to the middle of the colon there is intensive bacterial starch degradation so that in this place the difference between raw and thermically treated potatoes is only small. No matter what the previous treatment of the potatoes was, there is hardly any starch in faeces, i.e. it was nearly 100% digested up to the end of the digestive tract. The passage and digestibility resp. of ash and crude cellulose from the basic ration is not influenced by the supplement of raw or thermically treated potato products in the individual sections of the digestive tract. At the end of the ileum there are no differences between the apparent digestibility of the crude protein and absorption of amino acids of supplemented raw or cooked potato starch or steamed ensiled potatoes; after the use of raw ensiled potatoes they are, however, significantly more reduced than the comparison of analyses of faeces shows. In the large intestine the high amount of potato starch stimulates the metabolism and the reproduction of faecal bacteria as is shown by an increase by 20-30% in bacteria N excretion in faeces. Apparent crude protein digestibility and amino acid absorption are diminished by that. The increased N excretion in faeces after the supplement of raw potato starch to the basic ration is-in comparison with the supplement of heated starch-compensated by a commensurately lower N excretion in urine so that N retention practically remains uninfluenced by the supplement of variously treated potato starch.(ABSTRACT TRUNCATED AT 400 WORDS)

Animal Feed↗
PubMed1984

[Absorption and use of amino acids infused into the cecum of growing pigs. 4. Comparative studies on oral or cecal administration of 15N-lysine and 15N-urea, respectively].

12 pigs were divided into 4 groups. All animals received an identical basal diet deficient in lysine and additional isonitrogenous amounts of 66.4 mmol N in the form of 15N-lysine and 15N-urea resp. orally or caecally. Caecal application was carried out as permanent infusion through caecal cannulae. N- and 15N-balances were ascertained of all animals and the remain of the labelled nitrogen was determined. From the comparison of the N-balances the conclusion can be drawn that though caecally applied N-compounds, whether they were infused as amino acids or as non-amino acid-N, disappear in the large intestine, i.e. are digested, do not, however, improve the N-balance but are excreted as additional urine-N. Subsequent to oral application, lysine or urea are almost quantitatively absorbed in the small intestine. Absorbed lysine is used in the synthesis of body protein, absorbed urea, however, is almost completely excreted in urine (83% of the 15N-amount absorbed). 15N-excretion in faeces after the oral application of 15N-lysine and 15N-urea resp. was less than 1% of the 15N-amount applied, after caecal infusion, however, it was approximately 6%, the biggest part of which (70-77%) was incorporated in bacteria protein. After caecal infusion the main quota of the infused 15N-amount (greater than or equal to 80%) was excreted in urine, most of it in the form of urea. After the oral application of 15N-lysine this could be detected in both the TCA-soluble fraction of the serum and the serum protein. After caecal infusion 15N in the TCA-soluble fraction of the serum could mainly be found as NPN, absorption and incorporation of intact 15N-lysine were considerably lower. An calculation showed that the maximum of the absorbed 15N-amount in the form of lysine was 3% and that of the infused amount was 1.8%. It can generally be doubted that the absorption of lysine in the large intestine is significant in the protein metabolism. The absorption of utilizable lysine is practically completed at the end of the ileum. In the large intestine mainly the ammonia by the catabolic activity of the intestinal flora is absorbed and subsequently excreted through the intestines.

Administration, Oral↗
PubMed1984

[Relations between apparent fecal and apparent ileal crude protein digestibility in swine].

The crude protein and lysine digestibility values available in literature and ascertained in comparative investigations at the end of the small intestine (distal ileum) and in the complete digestive tract (faeces analysis method) of pigs were subjected to a correlation calculation in order to find out whether and to what degree there are relations between apparent 'ileal' and apparent 'faecal' digestibility. For both crude protein and lysine the relation between ileal and faecal digestibility is so close (r = 0.73 resp. 0.85 ... 0.98) so that for practical purposes it is not necessary to determine the apparent ileal digestibility for each feedstuff by means of the complicated cannula method. This can be calculated with great reliability from the experimentally ascertained apparent faecal digestibility. The differences between faecal and ileal digestibility are smaller for lysine (conversion factors 0.92 ... 0.99) than for crude protein (conversion factors 0.89 ... 0.93).

Animal Feed↗
PubMed1983

[Methodologic studies on protein metabolism and bioenergetics of protein deposition in growing animals. 4. Energy metabolism in chickens in connection with measurement of parameters of protein metabolism].

In connection with the measuring of parameters of the protein metabolism in parallel experiments, the energy metabolism of 6 chickens (origin Tetra B) in the live weight range between approximately 100 and 1,800 g was determined under conditions of restricted energy supply. 3 animals each received a feed mixture containing 20% (animal group 1) and 38% (animal group 2) crude protein. The amount of feed was daily increased by 1.5 g DM. The digestibility of energy and nitrogen was independent of the age. 66.3 +/- 3.3% and 64.0 +/- 5.0% resp. of the metabolisable energy were utilised for protein and fat retention. The energy maintenance requirement, determined at a live weight of 2,000 g, was independent of protein supply and averaged in the two animal groups 434 +/- 40 kJ metabolisable energy/kg live weight 0.75 . d. The result of multiple regression was, for the growth period investigated, an energy maintenance requirement of 403 +/- 32 kJ metabolisable energy/kg live weight 0.75 . d. 1.77 and 1.38 J metabolisable energy resp. were required for 1 J protein or fat retention. The energy requirement for protein retention was independent of the degree of protein supply. The results from the measuring of energy metabolism are discussed in connection with the kinetic parameters of protein metabolism ascertained in parallel experiments.

Animals↗
PubMed1983

[Effect of graded high-energy-level protein supply on fattening performance and retention and utilization of feed energy, protein and amino acids in female fattening swine. 4. Nitrogen and amino acid content in carcasses and parts].

The slaughtering and cutting up of 7 (6) female pigs in each of 3 groups (live weight approximately 113 kg) fed on approximately 80, 100 and 120% protein (lysine) of the norm as well as the determination of nitrogen and amino acids in the individual parts of the body had--in comparison to 6 reference animals (live weight approximately 36 kg) treated in the same way at the beginning of the experiment--the following results: In the course of growth the quota (in % of the slaughter weight) of bacon, belly fat + intestinal fat tissue is more than doubled; the relative quotas of bones, skin + ears, bristles + claws, blood and entrails, however, decrease. The total meat quota is 54% and remains relatively equal independent of the live weight. The N-quotas (in % of the empty body-N) of muscle and fat tissue and of the skin increase in the course of fattening, those of bones, useable organs and offal decrease distinctly. At the end of fattening the muscle protein of the animals amounted to 59% of the empty body protein and to 87% of the carcass protein. The amino acid content (g/16 g N) hardly changes in the individual parts during growth; the percentage amino acid distribution follows the weight-and N-distribution. The lysine content of the edible parts of the carcass is 8.4 g/16 g N. The chosen grades in the protein (lysine) supply of the test animals did not result in any significant changes with regard to the qualitative parameters (protein and amino acid content of the valuable and less valuable parts of the body as well as their percentage distribution in the empty body). The quantitative parameters (live weight gain, protein (amino acid) retention per day) are diminished in approximately the same relation as the insufficiency of the alimentary supply; by excessive supply, however, they do not significantly increase. The results are compared with corresponding data from literature and discussed.

Adipose Tissue↗
PubMed1982

[Nutrient composition of some newly bred high-protein and/or high-lysine cereal strains and digestibility by growing pigs. 2. Protein quality and digestibility of the amino acids].

After a first report on the nutrient composition and the digestibility of some newly bred varieties of cereals, information on the apparent digestibility of the amino acids in growing female pigs ascertained with the same test material is given. These data serve the evaluation of the quality of such cultivation products and the completion of the data in of feedstuffs tables and tables of the amino acid content. The newly bred barleystrains meet the requirement of digestible protein of pigs, wheat exceeds it whereas the maize samples fall short of it. The content of digestible lysine in the newly bred barleystrain approximate the requirement of growing pigs. There is ample digestible methionine + cystine in all samples. This again proves that newly cultivated barley and wheat rich in protein and lysine if accordingly supplemented with the limiting amino acid lysine can be used as sole feed for fattening pigs. Moreover, it becomes again obvious that the apparent digestibility of the amino acids can, for practical purposes, be sufficiently exactly evaluated with the help of the apparent digestibility of the crude protein of the respective feedstuff.

Amino Acids↗
PubMed1982

[Absorption and utilization of amino acids infused into the cecum of growing pigs. 1. Measurement of N-balance for utilization of lysine and isoleucine; isoleucine requirement for growing pigs].

In N-balance experiments with growing pigs (40-60 kg live weight) investigations were made whether lysine or isoleucine that is infused into the caecum can be absorbed there and to what extent these amino acids in that case can be utilised by the animal for protein synthesis. The pigs either received basic rations with insufficient lysine or isoleucine resp. (negative control group) or the amounts of lysine and isoleucine lacking to meet the requirement were supplemented with the feed (positive control group) or continuously infused into the caecum with the help of caecal infusion cannulae (test group). In the experiments with lysine the animals in the negative control group and in the test group showed considerably lower N-balances than the positive control group. There were no differences as regards the apparent digestibility of lysine between the positive control group and the test group. The urine of the test group contained distinctly more NH3. This shows clearly that lysine that is infused into the caecum cannot be utilised by the pigs, it is, on the contrary, microbially decomposed, the nitrogen is chiefly absorbed as NH3 and excreted in urine. As regards isoleucine, the deficit brought about with the basic ration was insufficient in order to achieve significant differences between the N-balance values of the groups so that unambiguous statements on the absorption and utilisation of isoleucine infused into the caecum cannot be made. Concerning apparent digestibility of isoleucine and the NH3 content of the urine, the results of the isoleucine experiments were similar to those in the lysine experiments. According to our N-balance experiments the isoleucine requirement of pigs indicated in relevant literature as 5.6 g/kg dry matter of the feed is by far too high. It should be limited to 3.5 or a maximum of 4.0 g isoleucine per kg dry matter of the feed.

Ammonia↗
PubMed1982

[Effect of graded protein supply at high-energy level on the fattening performance and the retention and utilization of feed energy, protein and amino acids by female fattening swine. 3. N retention and N and lysine metabolism determined by N balance and N analysis of the carcasses].

The slaughtering of female fattening pigs differently supplied with protein and lysine (nearly constant proportions) showed that a high supply (III) in comparison to the standard supply (II) did not bring about better results. The lower consumption of digestible crude protein and lysine (I) resulted in a prolonged fattening period, lower daily protein retention (by 23%) and a lower content in live weight growth (by 5%). The two feeding variants I and III are therefore ineconomical and not recommendable. There are significant positive correlations between N-retention calculated from 3 N-balance measurings in the first fattening period (up to the 44th fattening day) and N-deposit ascertained after the analysis at the carcasses at the beginning and at the end of fattening. By means of the calculated estimate functions (1) y = 4.724 + 0.5432x and (2) y = 7.850 + 0.4961x the level of the real protein deposition (y) in the total fattening period can be derived from the N-balance (x) both in g per animal and day (1) and in g per kg live weight growth (2). The four complexes of causes for the differences in N-retention according to N-balance and N-deposit according to carcass analysis: 1. high N-deposition in the first fattening period; 2. unascertainable N-losses 3. the difference between slaughtering and total body weight and 4. physiologically caused deviations in the N-storage of the living organism, are discussed. Protein and lysine utilisations are comparable with values from literature achieved under similar conditions. In the group supplied according to standard (II) it is 29.5 and 45.6% resp. or, related to the digested quota, 36.6 and 57.7% resp. Here the protein (10.1 kg) and lysine (1,640 g) assigned for a live weight growth of 80 kg (35-115 kg) in 100 fattening days were consumed, which means that 162 g lysine were needed for 1 kg deposited protein.

Abattoirs↗
PubMed1982

[Absorption and utilization of amino acids infused into the cecum of growing pigs. 2. 15N-labeled lysine].

Over a period of 4 days 15N-labelled lysine was infused into two growing female pigs (live weight approximately 50 kg) through a caecal cannula. The feeding was restrictive (1,400 g dry matter/day) and, with regard to lysine, it didn't meet the requirement. In a 7-day experiment the N- and 15N-content was measured periodically in the excretions (feces and urine), in various fractions of the blood and in selected slaughtering samples. From the infused 15N 3-5% are excreted as lysine in feces, another 5% are in other amino acids of the bacteria protein. The disappearance rate of 15N' from the large intestine makes greater than or equal to 90%. The biggest part of this 15N (78-88%) is excreted with the urine in form of 15N-urea. Obviously the infused amino acid is decomposed to NH3 in the large intestine and then absorbed. The absorbed ammonia is changed into urea in the ornithine cycle and excreted in urine. The recovery rate of the 15N infused as 15N-lysine is 93 and 84% resp. Incorporation of 15N in to serum protein or other body protein could not be detected so that the remaining difference of 7-16% cannot necessarily be interpreted as incorporation rate of 15N into the body protein. Under practical conditions the maximal utilisation of lysine from the feed in the large intestine is 1.6% and should thus be without importance.

Ammonia↗
PubMed1981

[Suitability of coarse rapeseed meals from various procedures for fattening broiler chickens. 2. Goitrogenic effect of rapeseed meals].

In a fattening experiment with rapeseed meals produced by different techniques (cf. Part I) on broiler chickens, each experimental ration contained 10% of a variant rapeseed meal. The thyroid glands of the broiler chickens (allotted to 8 groups according to their diets) were examined for mass gain and submitted to various histopathological, biochemical and morphometric procedures. The variants of rapeseed meal applied to the animals in the groups IV, III and I have been found to be toxic. In contrast, the effects of the other variants of rapeseed meal on the morphology of the thyroid gland have been negligible.

Animals↗
PubMed1981

[Preliminary experiments with rats on alkylresorcinols in rye].

Alkylresorcinols are present in some cereals, mainly in rye. Two feeding, growth and nitrogen balance experiments have been performed on rats to investigate the effects of 5-alkylresorcinols contained in a variety of rye. The results obtained from this investigation, tentative though they are because of the small number of animals, suggest that, in growing albino rats, neither the ingestion of feed nor the live weight gain nor the nitrogen retention is influenced by the application of extracted rye (freed from alkylresorcinols) or the excessive addition of rye oil or resorcinol to the diet.

Animals↗
PubMed1980

[Fistulation technic for the digestive tract of swine for the examination of protein metabolism].

Chyme may be collected quantitatively without grave risk from various sections of the intestinal tract of swine by reentrant cannulae, if such chyme is required for tests in the context of nutritional physiology. Techniques of anaesthesia and surgery for bridge fistula application are described together with the types of syringes needed as well as with aspects relating to presurgical and postoperative attention to the animals concerned.

Animals↗
PubMed1979

[Improving the nutritive value of rapeseed meal, using production process principles].

With regard to studies on production process variants designed to improve the nutritive value of rapeseed meal, the authors describe the principles underlying the modified diffusion extraction procedures used (with and without rapeseed husking). Furthermore, they briefly outline the chemical methods applied to the determination of the nutrient composition and glucosinolate content of rapeseed meal variants as well as the methodology of their feeding and nitrogen balance experiments on growing albino rats and broilers. The results obtained with 13 analytical variants and 8 biological variants confirm once more the beneficial nutritive effects obtained with the reduction of the glucosinolate content of rapeseed meal in monogastric animal species. However, these results do not permit to appraise unequivocally the repercussion of rapeseed husking on the diminution of the content of paraplastic substances in rapeseed meal. The diffusion techniques used for reducing the glucosinolate content in rapeseed meal have been found to be effective.

Animal Feed↗
PubMed1979

[Protein digestability and amino acid absorption in various segments of the digestive tract of pigs. 1. Methods of animal experimentation, protein content and amino acid patterns of the digesta in the small intestine and in feces after feeding different feeds].

Re-entrance cannulae were applied by way of operations at the end of the small intestine of a larger number of growing pigs. After a post-operative phase these animals were fed with various rations (N-free diet, fattening feed for pigs, rations with dried skim milk resp. wheat gluten + lysine and wheat + wheat gluten + lysine). During the main experiment periods the ileum digesta (24 hour-periods of collecting) and the feces were quantitatively registered. The protein and amino acid content ascertained in the feed rations, the digesta and feces samples are reported, comparatively evaluated and discussed. The amount of amino acids (in mg per kg intake of dry matter) contained in the ileum digesta after N-free feeding were statistically calculated with regard to differences occuring between the animals and days. For most amino acids a significant decrease in the ileum digesta could be detected during the course of the N-free feeding period. Moreover, the amount of amino acids in the ileum digesta was compared with the metabolic fecal amino acids, from which conclusions could be drawn concerning the disappearance rate of the individual amino acids in large intestine.

Amino Acids↗
PubMed1979

[Protein digestibility and absorption of amino acids in various segments of the digestive tract of pigs. 2. Protein and amino acid balances at the end of the small intestine and of the whole digestive tract (apparent and true protein and amino acid digestibility)].

Growing pigs with ileum and ileocecal re-entrant canulae were given 5 different rations (pig fattening feed 1 and 2, rations with dried skim milk, wheat gluten + lysine and wheat + wheat gluten + lysine). The crude protein and amino acid excretion was quantitatively determined with ileum chyme and feces. The calculation of the amino acid balances (apparent and true digestibility) at the end of the small intestine, at the end of the wholedigestive tract and the isolated colon showed characteristic differences for the individual amino acids. On ileum level the amino acids with relatively high endogenous quotas, threonine, tryptophane, alanine, aspartic acid and glycine showed a distinctly lower, the amino acids arginine, methionine, phenylalanine, glutamic acid, proline and tyrosine a distinctly higher digestibilityhan crude protein. In comparison of the values on the feces level, including the true digestibility, these differences are largely balanced out. At the end of the small intestine the absorption of the amino acids is in the main completed. The disappearance rate of amino acids from the colon shows large differences with reference to the different rations as well as the individual amino acids. They were particularly high for various rations as far as proline, tryptophane, glycine and cystine are concerned. If wheat gluten + lysine rations were given, a net synthesis of methionine in the colon could be proved.

Amino Acids↗
PubMed1979

[Protein digestibility and amino acid absorption in various segments of the digestive tract of pigs. 5. Results of the application of 35S-methionine].

The intake, excretion and the rate of flow of protein, methionine and 35S were measured at four pigs (live weight 63 kg) with re-entrant cannulae in the duodenum and the ileocecal region after the oral application of 35S-methionine and the feeding with a wheat + wheat gluten + lysine resp. a protein-free diet over a period of 7 days. From the measured values one pattern each for the N- and the methionine metabolism was laid down with the help of the compartment model, and the endogenous and exogenous levels of protein resp. methionine in the duodenum, the ileum and in feces were estimated.

Amino Acids↗