Biomedical subjects

H Bergner

Publications and source records attributed to H Bergner.

At least 37 records · Page 2Linked to original sources

PubMed1991

[ATP in the metabolism of ruminants].

The ATP yield from the carbohydrates of anaerobically living microorganisms in the rumen amounts to only 5-10% of the ATP yield of the intermediary metabolism in the presence of oxygen. Vital functions and thus microbial protein synthesis are due to protein degradation in the rumen. The ATP yield in the intermediary metabolism of ruminants is mainly achieved from propionate and microbial protein by means of gluconeogenesis because the absorption of glucose from digested starch is very low. The relationships between ATP yield in the rumen and the processes of glucose provision for the production of lactose as well as the protein content of the milk are shown. As important processes of ATP production in microorganisms from easily soluble carbohydrates take place in silage preparations before feed intake, the corresponding consequences for the metabolism of high-performance cows fed with silage are shown.

Adenosine Triphosphate↗

PubMed1991

[The determination of a gross utilization of 15N-lysine in laboratory rats. 1. Experiment with normal intestinal flora (without antibiotic supplement)].

Wistar rats of a live weight of about 100 g were divided into 14 groups (5 animals/group). The rations given supplied the animals with 75%, 100% and 125% lysine, which brought about a moderate growth of the animals of approximately 2 g/animal and day achieved by limited feeding. The 3 lysine levels mentioned could be achieved by lysine supplements (L-lysine-HCl) for the following rations: barley (B), wheat (W), and wheat gluten (WG). For isolated soybean protein (assay protein) (S) the lysine levels 100% and 125% and for soybean meal (SM) the levels 116% and 125% could only be achieved. A control group with whole egg ration (W) (with its natural lysine content of 125% of the requirement) were also tested as comparison. During the 10-day period of the main experiment all 14 rations were supplemented with 0.5 g 15N-lysine (alpha amino group, 95% labelled with 15N). The N balance could only be significantly improved by lysine supplements in the rations B, W and SM with the lysine level of 125%. The biologic value of the protein sources was in rations B and WG also significantly improved by the highest lysine supplement. 15N excess (15N') from the deaminated 15N lysine was excreted with diet B rich in crude fibre mainly in faeces (more than 15% of the intake) and only about 10% in urine. With the diets without native crude fibre the excretion quota changed in favour of urine. The following 15N' amounts in per cent of 15N' intake from lysine were excreted in urine and faeces: B 75 = 31.3, B 100 = 30.9, B 125 = 28.0, W 75 = 24.3, W 100 = 32.2, W 125 = 32.6, GW 75 = 18.3, WG 100 = 24.2, WG 125 = 28.1, S 100 = 39.4, S 125 = 50.4, SM 116 = 34.9, SM 125 = 32.9, W 125 = 19.1. 15N excretion in urine and faeces increased in comparable relations in 6 cases of lysine increase levels only. Gross utilization of lysine can only conditionally be quantified by 15N labelled lysine supplement.

Animal Feed↗

PubMed1991

[Detection of microbial protein synthesis in the small intestine of sheep using an intraduodenal 15N-urea infusion].

Sheep (3 animals, 50 kg LW) with reentrant cannulas in duodenum and at the end of the ileum received 700 g hay and 800 g alfalfa pellets per animal and day. In a previous 1st period of three days duodenal digesta and in a 2nd period of four days ileal digesta were collected and stored deep frozen. In the main period the digesta flow was interrupted for 28 hours. The duodenal and ileal digesta were collected quantitatively. The previously collected duodenal and ileal digesta portions were introduced hourly. The duodenal digesta was supplemented with 15N-labelled urea for a 24 hour period. 4.5% of the introduced 15N-excess were detected at the end of the ileum in the 24 hour period. 5.6% of the 15N-excess at the end of the ileum were incorporated in bacterial protein. It was measured that the ileal digesta contained 4.62 g N in the TCE precipitable fraction and 24.4% of the TCE precipitable N-fraction was bacterial nitrogen.

Animals↗

PubMed1990

[Determination of a prececal N-absorption from natural feed by 15N-labeled laboratory rats using the isotope dilution method].

60 Wistar rats (5 animals/group) received 12 different feedstuffs over a period of 7 days and were simultaneously labelled with 15N (orally by means of 15NH4Cl in the feed). In the subsequent 5 days faeces were collected in order to determine the apparent and true digestibility of crude protein. On the 13th experimental day the animals were killed 3 hours after the intake of half the daily ration and the atom-% 15N excess (15N') was determined in the TCA-soluble and TCA-precipitable fractions of the blood plasma and the digesta of the 2nd and 3rd thirds of the small intestine. Precaecal N-absorption was calculated with the help of the quotient [formula: see text] the blood plasma and the digesta The following values (in %) were registered in comparison to true N-digestibility (in the following in brackets): casein = 95.8 (99.2), whole egg = 92.1 (97.5), fish meal = 85.8 (93.4), dried skimmed milk = 98.4 (96.1), soybean meal = 79.6 (90.6), assay protein = 94.2 (98.9), wheat = 92.9 (90.7), barley = 84.3 (84.8), yeast, grown on molasses = 85.6 (87.2), yeast, grown on whey = 86.1 (88.5), biomass of liquid manure = 43.6 (68.9), activated sludge = 54.4 (64.1). One can conclude that the isotope dilution technique demonstrated here as an evaluation method is very well suited for the characterization of the N-digestibility of a feedstuff in the small intestine.

Animal Feed↗

PubMed1989

[Nitrogen metabolism in the large intestine of ruminants. 6. Metabolism of intracecally administered 14C and 15N urea in sheep with simultaneous intracecal doses of heat-damaged hay].

Two wethers (28 kg and 33 kg) were supplied with ileocaecal re-entrance cannulae and received a straw pellet ration rich in crude fibre (70.5% straw, 12% chopped sugar beet, 10% cereals, 2% urea, 3% NH4HCO3 and 2.5% of a mineral mixture). In a preliminary period 50% of the digesta flow was collected on 6 successive days for 18 h each. An amount of digesta sufficient for 24 h was apportioned for hourly application and stored at a temperature of -20 degrees C for the main trial. In the main trial the two animals received intracaecally the collected digesta with a supplement of ca. 6 g hay damaged by heat/kg LW(0.75) in hourly portions over 24 h (hay made up ca. 15 and 20% resp. of the DM amount). In addition, each digesta sample was supplemented with 14C and 15N labelled urea (19.7.10(6) Bq 14C urea and 364 mg 15N excess from 15N urea). About 9% of the applied 15N amount was microbially utilized; the utilization quota was thus lower than after the application of partly hydrolyzed straw meal (16% in a previous trial). The 14C activity from 14C urea was quickly eliminated in the form of CO2 in the respiratory gases (at the 18th hour after the end of the infusion 70% excreted as CO2). The half-lives for the urea resulting from the semi-logarithmic decrease of the atom-% 15N excess in the blood plasma were 7.9 and 7.7 resp. 23% and 34% resp. of the applied 15N excess were excreted in urine. The excretion of radioactive carbon in urine, however, was at 2.8% and 4.3% resp. of the applied amount very low 120 h after the beginning of the trial (96 h after the end of the infusion). On the whole one can conclude from this trial that hay damaged by heat has only a low stimulating effect on microbial activity in the large intestine.

Animal Feed↗

PubMed1988

[The significance of fiber for swine nutrition with special reference to HCl-treated straw meal].

The term crude fibre according to the Weend analysis method is insufficient for the nutrition of pigs as it does not comprise pentosanes. During the cooking process they are hydrolysed with diluted acid and do not remain in the crude fibre fraction. As stomach HCl can also hydrolyse pentosane (probably in shorter chains), they are well utilized by the microorganisms in the digestive tract (production of volatile fatty acids). Cereal bran and straw meal contain a particularly high quota of pentosanes in their fibre. The fibre fraction of the plant materials fulfills several functions in the digestive tract: absorption of water at the hydroxyl groups of cellulose and hemicellulose (higher absorption capacity of the digesta and improved passage rate); formation of volatile fatty acids (VFA) by the intestinal bacteria due to the fermentation of pentosanes and cellulose (positive influence of VFA on the mucosa of the intestinal walls); absorption of protein decomposition products (including amines) in the cavities of native plant scaffold substances and absorption of aromatic toxic substances (tyramine, phenol, cresol, tryptamine, indole, skatole, histamine etc.) in the lignin by means of VAN DER WAALS forces and further transport of the toxic substances until they are excreted in faeces. HCl treated straw meal is either a mixture of HCl and straw meal at a ratio of 20 kg half concentrated HCl (17% HCl) and 100 kg straw meal with or without heat treatment (steaming for ca. 30 min). The unsteamed product is called HCl straw meal, the steamed product partly hydrolysed straw meal (PHS). 5-10% HCl--straw meal was successfully used in the rearing of piglets after weaning. In addition to the above-mentioned significance of the scaffold substances for the digestive tract, the HCl improved the pH status in the stomach and the upper region of the small intestine. PHS neutralized with CaCO3 (up to pH 6-7) is suitable for breeding sows, boars, young sows and fattening pigs. PSM contains 25% reducing substances (reducing sugars) in the DM and serves the intestinal bacteria in the production of VFA. In the feeding of breeding sows in the phase of gestation 20-30% of the DM intake could be covered by PSM. The number of viable and rearable piglets was significantly higher than after conventional feeding. HCl--SM and PSM also provide advantages with regard to hygiene. They are not congested by fungi and can well be stored without neutralization.

Animal Feed↗

PubMed1987

[Methodological studies of the metabolism-oriented determination of the lysine requirement in broiler chickens. 1. Influence of the lysine content of the diet on the lysine oxidation rate in short-term food withdrawal before 14C-lysine injection].

For the estimation of lysine requirement 128 male broiler chickens were used at an age of 7 to 21 days posthatching. They received a lysine deficient diet composed of wheat and wheat gluten. To this basal diet L-lysine-HCL was supplemented successively resulting in 8 lysine levels ranging from 5.8 to 23.3 g lysine per kg DM (2.2 to 8.7 g lysine per 16 g N). At the end of the two-week feeding period of the experimental diets 14C-lysine was injected intravenously 1.5 and 5.5 hours after feed withdrawal. During the following 4 hours the excretion of CO2 and 14CO2 was measured. This 4 hours absorption period for 14CO2 was regarded as sufficient according to a preliminary experiment. The highest daily gain of 21.5 g was observed in animals fed 13.3 g lysine/kg DM. Lysine concentrations exceeding 18.3 g/kg DM depressed body weight gain. The CO2-excretion was not influenced by lysine intake. The 14CO2-excretion was low with diets low in lysine content and increased 3 to 4 times with diets meeting the lysine requirement. Based on measurements 1.5 to 5.5 hours after feed withdrawal the saturation value for lysine was reached at 13.3 g/kg DM. This value was lowered (10.8 g/kg DM), however, if the estimation was carried out 5.5 to 9.5 hours after feed withdrawal. These results suggest a higher metabolic lysine requirement during the earlier period after feed intake. Both, reduced weight gain and non linearity in 14CO2-excretion with diets exceeding a lysine content of 18.3 g/kg DM indicate a limited capacity of the organism to degrade excessive lysine. According to the results of this experiment for broiler chickens 3 weeks posthatching a lysine requirement between 10.8 and 13.3 g/kg DM (27% CP and 660 EFUhen/kg DM) was concluded. The range of estimated requirement data could be narrowed by the use of diet with other lysine content.

Animals↗

PubMed1987

[Methodologic studies on the metabolically-oriented determination of lysine requirements in broiler chickens. 2. Effect of the lysine content of the diet on the lysine oxidation rate in a 15-hour feed withdrawal before 14C-lysine injection].

This experiment was designed to narrow the estimated range for lysine requirement of broiler chickens determined by isotopic techniques. In addition the influence of a long-term feed withdrawal previous 14C-lysine-injection on the lysine catabolism was investigated. 120 male broiler chickens 7 to 21 days posthatching received a diet based on wheat and wheat gluten. Lysine content was varied from 8.3 to 16.0 g/kg DM (3.2 to 6.3 g/16 g N) at 8 levels by supplementing the basal diet with L-lysine-HCl. After the feeding period animals of each group were labelled with 14C-L-lysine by intravenous injection 5.5 and 15.5 hours after feed withdrawal, respectively. During the following 4 hours the excretion of 14CO2 and CO2 was measured. Highest body weight gain was observed in the group with 13.8 g lysine/kg DM. In case of 14CO2 excretion measurements starting 5.5 hours after feed withdrawal an increase of 14CO2 excretion was observed if the lysine content of the diet exceeded 11.6 g/kg DM. This estimated range for lysine requirement (11.6 to 12.7 g/kg DM with 26% CP in the DM) was lower compared with the lysine requirement estimated by the growth curve (12.7 to 13.8 g/kg DM). This discrepancy could be explained by the fact that the results of the metabolism oriented determination of lysine requirement represent the requirement at the actual age, while the feeding experiment reflects a mean lysine requirement of the previous period of 14 days. If the animals were labelled with 14C-lysine 15.5 hours after feed withdrawal no clear response in 14CO2 excretion and specific radioactivity of CO2 on the dietary lysine content was observed.

Animal Feed↗

PubMed1987

[Methodologic studies on the metabolism-oriented determination of methionine requirements of broiler chickens].

In a preliminary experiment the time course of 35S-excretion following a single injection of 35S-methionine in male broiler chickens was measured for 5 days. Within 2 days 65 to 69% of the amount of 35S excreted during the whole 5-day-period were recovered. Therefore, in the main experiment excrements for 35S measurement were collected only 2 days. During the main experiment starting 7 days posthatching 48 male broiler chickens received diets based on peas and wheat. The basal diet was supplemented with DL-methionine at 8 levels increasing the methionine content from 3.3 to 7.5 g/kg DM or 1,51 to 3.42 g/16 g N and the content of sulphur containing amino acids varied from 6.8 to 11.8 g/kg DM or 3.11 to 5.02 g/16 g N, respectively. Daily body weight gain was followed up to day 30 posthatching and N-balance was estimated during the 21st to 26th day posthatching. Up to day 26 a methionine content of 3.9 g/kg DM was sufficient for maximum weight gain. However, during the last period of the experiment highest weight gains were observed in animals receiving diets with 4.5 or more methionine/kg DM. Highest N-retention (1.2 g N/d) was measured if the diet contained 3.9 g methionine/kg DM or more. At day 28 posthatching 35S-methionine was injected intravenously and the subsequent 35S-excretion was measured. The 35S-excretion started to increase at a methionine content in the diet of 4.5 g/kg DM and continued to rise up to the highest methionine content of 7.5 g/kg DM. The metabolism oriented methionine requirement determination indicates for male broiler chickens at the beginning of the 5th week posthatching a methionine requirement of 3.9 to 4.5 g/kg DM (1.78 to 2.05 g/16 g N) and a requirement of S-containing amino acids of 7.4 to 8.0 g/kg DM (3.38 to 3.65 g/16 g N). The method used is potential in studying the age-dependent changes in methionine requirement.

Animal Feed↗

PubMed1987

Estimation of the endogenous N proportions in ileal digesta and faeces in 15N-labelled pigs.

Four 40 kg castrated male pigs fitted with simple 'T' cannulas in the terminal ileum were given 15N-labelled ammonium salts, added to a low protein diet, for 6 days. Excretion of 15N in urine and faeces was monitored daily throughout the labelling and subsequent experimental periods. During the experimental period the pigs were given a diet based on wheat and fish meal, supplemented with varying levels of partially hydrolysed straw meal to give crude fibre contents ranging from 40 to 132 g/kg. After adaptation to the particular levels of straw meal, faeces and ileal digesta were collected during successive 24 h periods. N digestibility values were determined by the chromic oxide ratio method. The retention of 15N labelled non-specific N was 0.46 of the dose given. The validity of using urine values as a measure of 15N abundance in endogenous N was demonstrated by the similarity of 15N abundance in urine immediately before slaughter at the end of the experiment and in the digestive secretory organs thereafter. The average amount of endogenous N passing the terminal ileum was 3.4 g/day or 0.30-0.50 of total ileal N flow. This was not affected by dietary fibre level. The proportion of faecal N which was of endogenous origin was similar to that in ileal digesta, suggesting similar utilization of endogenous and residual dietary N by hindgut bacteria. Half the endogenous N entering the large intestine was reabsorbed there. Increasing dietary crude fibre from 40 to 132 g/kg increased faecal endogenous N excretion from 1.3 to 2.0 g/animal and day.

Animals↗

PubMed1987

[Influence of the physical properties of straw pellets on their digestibility and passage rate of Cr2O3 in sheep].

By means of pelleting them one to four times (press G 600) and adding 20% sugar beet chips and 3% ammonia hydrogen carbonate at varying loose density (357-561 kg/m3) 4 straw pellet charges were produced. Significant differences could be ascertained for these pellets with regard to the fineness coefficient (I-IV 1.67; 1.30; 1.19; 0.83), hardness of pellets (5.4; 8.8; 9.4; 18.6 N/m2/10(5) and partly the loose volume. After testing four wethers per group, an energy concentration in the same sequence was ascertained as follows: 409, 388, 377 and 382 EFUcattle/kg dry matter. Apart from a higher crude fibre digestibility of groups I and II compared to III there were no significant differences in the digestibility. The measuring of feed passage time with the help of Cr2O3 did not result in directed differences. On an average of all groups, 80% of the Cr2O3 excretion was achieved after 70.5 +/- 0.7 h. The mean retention time of Cr2O3 in the digestive tract in all four groups was in average 53.3 +/- 1.2 hours. The different fineness degrees and values of the hardness of straw pellets remained without significant effects on the feed value of the straw pellets in the experiments with sheep.

Animal Feed↗

PubMed1986

Studies on the secretion of amino acids and of urea into the gastrointestinal tract of pigs. 3. Secretion of urea determined by continuous intravenous infusion of 15N-urea.

Three pigs, of 34 kg live weight, were each fitted with re-entrant cannulas both in the duodenum and terminal ileum and catheters in the jugular vein and in the carotid artery. Pigs received a diet based on wheat and dried skimmed milk in equal amounts at 12 h intervals. During the preliminary period the digesta flowing from both duodenal and ileal cannulas were collected over 12 h after feeding on two consecutive days and half of them were reintroduced into the gut and half were stored at -20 degrees C. During the experimental period 15N-urea was infused into the jugular vein for 12 hours starting with the morning meal. Total amount of urea infused was 5 g containing 1.22 g 15N-excess. The digesta from both proximal duodenal and ileal cannulas were collected and stored, while the digesta from the preliminary period were reintroduced into the respective distal cannulas. Blood samples were taken at different time of infusion. At the end of infusion period the animals were sacrificed and samples of the contents of the digestive tract and tissues were taken. Urea flux calculated according to atom-% 15N-excess of urea N in plasma was 1.23 to 2.37 g/kg body weight/day. In the duodenal digesta 94.5 +/- 0.2 and in ileal digesta 57.1 +/- 7.39 per cent of 15N were in the TCA soluble fraction. The total amount of 15N in the duodenal digesta was 1.7 to 6.3 times greater than in the ileal digesta. Only small amount of 15N was found in the caecum and almost none in the contents of colon and rectum. It is concluded that urea is secreted into all parts of the digestive tract, the main sites of urea secretion being pancreatic juice and/or bile as well as the small intestine. The total amount of urea secreted is assumed to be similar to the daily urea excretion.

Amino Acids↗

PubMed1986

Studies on the secretion of amino acids and of urea into the gastro intestinal tract of pigs. 1. Secretion of leucine into the stomach and upper part of the duodenum during continuous intravenous infusion of 14C-leucine.

Three pigs of 34 kg live weight were fitted with a re-entrant cannula in the duodenum, and with two catheters placed in the jugular vein and carotid artery. They were fed 1.2 kg/d of wheat-dried-skimmed milk diet. Digesta from the proximal duodenal cannula were collected for 12 h on 2 consecutive days; 50% were reintroduced into the respective distal cannula and 50% were stored at -20 degrees C. Three days later 14C-leucine was infused into the jugular vein for 12 h, starting with the morning meal. During this period the digesta from the proximal cannula were collected and stored for analysis while the digesta collected previously were reintroduced into the distal cannula. Blood samples were taken from the carotid artery. The total flow of duodenal digesta in 12 h was 5760 +/- 530 g. On average 70 percent of the radioactivity in digesta was associated with the TCA-precipitable fraction. During hours 0-3 and 11-12 of infusion 60-70% and 96-98% of the radioactivity in the TCA precipitable fractions was in leucine. In the TCA soluble fraction only 30-40 per cent of the radioactivity was associated with leucine. At the plateau 2.1 and 3.3% of infused 14C-leucine and of radioactivity were recovered in the duodenal digesta. The calculated amount of endogenous protein passing the duodenum was 20.4 g/d/pig. The results are discussed in relation to previous studies on protein synthesis and secretion in which 14C- and 15N-amino acids were used.

Amino Acids↗

PubMed1986

Studies on the secretion of amino acids and of urea into the gastro intestinal tract of pigs. 2. Net secretion of leucine into the small and large intestines.

The experiment was carried out on 3 pigs of 34 kg body weight equipped with re-entrant cannulas both in the duodenum and terminal ileum. Furthermore, catheters were inserted into the external jugular vein and into the carotid artery. During a preliminary period digesta from both cannulas were collected and stored. This digesta was than reintroduced during a 12 hours period of intravenous infusion of 14C-leucine while outflowing digesta from the proximal parts of the cannulas were collected, stored and analyzed for leucine content, 14C-radioactivity and specific radioactivity of leucine. This paper reports the net secretion of 14C-activity and of 14C-leucine by the small intestine and the recovery of both in the content of the digestive tract at the end of the infusion. It was concluded that endogenous leucine enters the lumen of the small intestine through the intestinal wall mainly in a protein bound form. Free leucine is secreted, however, only in small amounts. Metabolites of leucine were also secreted into or formed in the lumen of the small intestine. A proportion of endogenous leucine was reabsorbed during the passage of digesta along the small intestine.

Amino Acids↗

PubMed1986

[Nitrogen metabolism in the large intestine of ruminants. 2. Metabolism of i.v. infused 15N-urea by additional supply of fermentable material to the large intestine of bulls].

The experiment was carried out on 3 bulls with body weights of 201, 168 and 190 kg, respectively. The animals were equipped with a ileo caecal re-entrant cannula and with catheters in the jugular veins on both sides. The pelleted ration was composed of straw 70-72%, cereals 10%, molasses 12-41%, ammoniumhydrogencarbonate 3%, urea 2% and mineral mixture 1%. During a preliminary period ileal digesta were collected, deep-freezed and stored. During the main experiment 15N-urea was infused intravenously for 24 hours. In this period and during the following 6 hours outflowing ideal digesta were collected quantitatively. At the same time precollected, unlabelled digesta together with a supplement of partly hydrolysed straw meal were reintroduced into the caecal part of the cannula. Plasma urea-N, urinary-N as well as several N-fractions of faeces and digesta were analysed for 15N abundance. A urea flux rate of 27.9 +/- 3.4 mumol per minute per kg 0.75 was estimated. It was calculated that 52% of this amount of urea was transferred into the digestive tract. In both, digesta and faeces NH3-N was highest 15N-labelled indicating a direct urea entry and degradation in both segments of the digestive tract. The amounts of 15N-excess found during the period of digesta replacement were in faeces 0.25 and in ileal digesta 4.02% of the infused amount of 15N. Although the microbial utilization of endogenous urea-N was generally low in the large intestine there was a clear stimulation of this process due to the additional supply of the large intestine with a fermentable source.

Animals↗

PubMed1986

[Nitrogen exchange in the large intestine of ruminants. 4. Exchange and isotope balance of intracecally administered 14C- and 15N-urea in sheep with simultaneous intracecal dose of a partly hydrolyzed straw meal].

Two experiments were performed with wethers (Body weight 34 to 44 kg) receiving a ration rich in crude fibre at maintenance level. The animals were fitted with ileocaecal cannulas into which 14C-, 15N-labelled urea together with digesta was introduced hourly for a 24 hours period (V1; 2 animals). In experiment two (V2; 3 animals) in addition HCl-partly hydrolysed straw meal was introduced. After ureolytic degradation the intracaecal applied urea entered mainly the intermediary metabolism. The resulting ammonia was resynthesized to urea without any time lag. The rate constant for the increase in 15N labelling of urea was 3.2 d-1 in both experiments. Urea leaves the plasma with half lives of 10.6 (V1) and 5.2 (V2) hours. More than 60% of the applied urea were excreted with urine. Formed 14CO2 appeared at proportions of 66% (V2) and 71% (V1) in the respiration gases. Both, the decline of the 14C-activity in blood plasma and the specific 14C-activity of CO2 in the respiration gases after the end of the labelling period do not follow a kinetic of first order. The 15N-labelling of the NH3-N in ileal digesta was very high and reached plateau values similar with those of plasma urea (2.54 vs. 2.56 atom-% 15N-excess). A direct entry of plasma urea into the small intestine was concluded.

Animals↗

PubMed1986

[Nitrogen metabolism in the large intestine of ruminants. 3. Microbial utilization of intracecally administered 14C- and 15N-marked urea in the large intestine of sheep in simultaneous intracecal administration of partially hydrolyzed straw meal].

Two experiments were performed on sheep, receiving on maintenance level a pelleted straw ration high in crude fibre (straw, 70.5%; dried sugar beet pulp, 12%; cereals, 10%; urea, 2%; ammonium hydrogen carbonate, 3%; minerals 2,5%). The animals were fitted with ileo-caecal re-entrant cannulas. The effects of the introduction of HC1-partly hydrolysed straw meal into the digesta of the large intestine on the digestion processes in that segment were studied. Under these conditions the metabolism of 14C and 15N labelled urea, which was given into the caecum, was estimated. In experiment 1 (E 1; 2 animals) unlabelled, precollected digesta were hourly reintroduced together with 14C and 15N labelled urea via the caecal cannula. In experiment 2 (E 2; 3 animals) the digesta were supplemented with partly hydrolysed straw meal (10% of the mean daily DM-intake with the ration). The supplement of partly hydrolysed straw meal caused an increase of the 15N excretion with faeces from 13.4% (E 1) to 19.8% (E 2) of the dose. The 15N was mainly incorporated in the bacterial fraction (98% E 1; 96% E 2). As a reason for the increased 15N incorporation into the bacterial fraction of 106.4 mg15N' in E 2 vs. 67.3 mg15N' in the experiment without straw meal supplement the higher supply of energy as fermentable carbohydrates was assumed.

Animals↗

PubMed1985

[Rearing of female cattle twins using complete feed pellets in comparison to straw pellets plus concentrate mixture. 1. Weight gain performance and feed expenditure as well as rumen fermentation conditions during the 4th-12th months of life].

The investigations with young female cattle (twin cattle, n = 30) the applicability of straw as sole roughage after the end of the suckling period was tested. Completely (I) and partly (II) pelleted rations of dried feed with a straw component of 65% each in the total rations were used. Feed intake, development of body weight, feed expenditure as well as indexes of rumen fermentation and of the concentration of some metabolism parameters in the blood serum were measured. In the complete test period (between 5th and 12th months of life, 243 days) there were not any significant differences between the groups in all registrations. Average daily weight gains of 570 g were achieved with an overall high dry matter (2.6 kg/100 kg live weight) and roughage (straw) intake (1.6 kg dry matter/100 kg live weight). The standard expenditure of energy and protein given for the stage of development was differentiatedly undercut. The energy expenditure being below the standard (ca. 10%), the total energy expenditure (kEFUcattle) was by 20 (II) and 25% (I) below standard expenditure. Energy expenditure aimed at weight gain reached very satisfactory values with 3.68 (I) and 3.79 kEFUcattle/kg weight gain (II). Protein expenditure fell short of the standard for the development stage by 14 (II) and 20% (I) resp. All parameters ascertained of the rumen and intermediate metabolism were in the physiologic standard range, as is characteristic of feeding regimes with a relatively high quota of roughage.

Age Factors↗