Biomedical subjects

W Jentsch

Publications and source records attributed to W Jentsch.

At least 37 records · Page 2Linked to original sources

PubMed1994

[Energy and nitrogen metabolism of pregnant and lactating sows and suckling piglets. 5. Energy and nitrogen metabolism of pregnant sows].

The energy and nitrogen metabolism of pregnant sows was measured with the method of indirect calorimetry in dependence on the number of gestation (1,2 and 4), on the energy supply (120, 100 and 80% of the requirement recommendation) and on the gestation stage. Values of maintenance requirement and of energy and nitrogen utilization for body deposition were calculated on the basis of results of energy and nitrogen metabolism. The energy maintenance requirement increased from 389 to 435 and 473 kJ metabolizable energy per kg LW0.75.d with rising number of gestation. The heat production increased from 85th to 115th day of gestation by 6%. The efficiency of the partial energy utilization for the energy deposition amounted to 66% on the average. The efficiency of the partial utilization of digestible nitrogen for the nitrogen deposition was calculated to 75%. The nitrogen maintenance requirement values amounted to 0.5 and 0.4 g digestible nitrogen per kg LW0.75.d in the 1st and 2nd half of gestation.

Animal Feed↗

PubMed1993

[The effect of the phosphorus supply on the energy metabolism of growing swine].

In growing barrows (live weight 17-30 kg) 3 g P/kg DM feed resulted in comparison to 6 g P/kg DM in 8% lower live weight gain. The lower live weight gain had no relation to N- and energy retention. The lower P feeding has only low effect on energy excretion in faeces and urine (1% of gross energy). A submarginal P feeding has no influence on N- and energy metabolism of growing pigs.

Animal Feed↗

PubMed1993

[The effect of starch sources barley, corn and potatoes and their ration proportions on nutrient digestibility and energy utilization in ruminants. 2. Fractions of ruminally and postruminally digested nutrients in cattle].

The investigations of this paper are part of a complex research project to develop energetic feed evaluation within the Net Energy Fat System. The aim was to obtain new results to estimate the relation between place as well as kind of nutrient digestion and energetic utilization of rations in cattle. The ruminal nutrient digestibility was measured in adult oxen on feeding level 1.7 by means of duodenal reentrant cannula for 9 rations including the starch sources barley, maize and potatoes and with their energy parts of 50, 25 and 10%. The intake of starch ranged from 484 to 2573 g/animal.d and the amounts of ruminal and postruminal digested starch from 444 to 2336 as well as 10 to 284 g/animal.d. For the organic matter, starch, water soluble carbohydrates and N free residual substances high relative parts of ruminal digested from apparent digested nutrients were measured with values between 78 and 88, 83 and 98, 93 and 97 as well as 88 and 100% respectively.

Animal Feed↗

PubMed1993

[Comparative studies of the parameters of rumen fermentation and the digestibility of feed rations in cattle and sheep. 1. Parameters of rumen fermentation].

The results from 283 studies of rumen liquid, taken by means of oesophagus probe, from different species of cattle (ox, cow, male and female young cattle) and sheep (adult wether) are compared. In the rumen liquid the parts of volatile fatty acids (VFA), total VFA content, pH value and the content of NH3 and urea were analysed. In the cattle's rumen liquid the part of acetic acid is on average 2 Mol-% and the content of total VFA up to 28 mmol/l (middle of the cow--sheep comparisons) higher than in that of wether. The contents of NH3 and urea are lower in cattle than in wether. Relations between the amount of difference of characteristic rumen fluid numbers of cattle and sheep and the crude fibre content of the rations, the live weight of the young cattle and the nutrition level are considered.

Ammonia↗

PubMed1993

[Comparative studies of the parameters of rumen fermentation and the digestibility of feed rations in cattle and sheep. 2. The digestibility of feed rations].

The results from 283 comparisons of digestibility in cattle (ox, cow, male and female young cattle) and sheep (adult wether) are presented. The crude protein content of the applied rations ranged from 90 to 340 and the crude fibre content from 80 to 430 g/kg DM. Within the range of rations with 200-350 g crude fibre per kg DM the differences between adult cattle and wether in the digestibility of energy and organic matter don't exceed 1%-unit (mean -0.5 +/- 2.5), that of crude protein is 5%-units lower in adult cattle than in adult wether. In young cattle digestibility is altogether lower than in wether; in young cattle with 120 to 200 kg live weight 4 to 6 and in more developed cattle 3 to 4 digestibility units for energy. In the metabolizability of the energy in comparison between adult wether and the different animal categories of cattle the difference don't exceed 1.5%-units. Relations between the live weight of cattle, the crude fibre of the rations as well as the nutrition level and the amount of difference of digestibility between cattle and sheep are considered.

Age Factors↗

PubMed1993

[Dependence of gross energy, digestive energy and metabolizable energy of feed and the energy disposition on the content of digestible nutrients in relation to starch and sugar. The progress of energetic feed evaluation. 1. Results from studies on swine].

On the basis of an analysis of energy metabolism measurements on adult pigs, fed on 92 ratios with very heterogeneous nutrient composition, the following prediction equations for gross energy (y1), digestible (y2) and metabolizable energy (y3) as well as for energy deposition effect of ratios (y) (kJ) are presented: y1 = 23.6z1 + 39.8z2 + 17.3z3 + 16.0z4 + 18.9z5 y2 = 23.6x1 + 39.8x2 + 17.3x3 + 16.0x4 + 17.2x5 y3 = 20.5x1 + 39.8x2 + 17.3x3 + 16.0x4 + 17.0x5 y = 11.0x1 + 34.0x2 + 12.7x3 + 11.6x4 + 5.0x7 + (12.0-0.14(80-x6))(x5-x7) [table: see text]

Animal Feed↗

PubMed1993

[Dependence of gross energy, digestible and metabolizable energy of feed and the energy onset on the content of digestible nutrients in regard to starch and sugar. A contribution to the further development of energetic feed evaluation. 2. Results from studies of cattle].

On the basis of an analysis of energy metabolism measurements on adult cattle (oxen), fed on 110 rations with very heterogeneous nutrient composition, the following prediction equations for gross energy (y1), digestible (y2) and metabolizable energy (y3) as well as for energy deposition effect of rations (y) (kJ) are presented: y1 = 23.6z1 + 34.0z2 + 17.3z3 + 16.0z4 + 19.1z5 y2 = 23.6x1 + 34.0x2 + 17.3x3 + 16.0x4 + 18.0x5 y3 = 17.3x1 + 34.0x2 + 15.9x3 + 15.1x4 + 15.4x5 y = (6.5x + 26.6x2 + 10.1x3 + 7.5x4 + 8.9x5) (-0.5574 + 0.04050x6 - 0.0002633x6(2)) [table: see text]

Animal Feed↗

PubMed1993

[Effect of the starch sources barley, corn and potatoes and their ration portions on nutrient digestibility and energy utilization in ruminants. 3. Energy utilization in cattle].

With investigations on the influence of different starch origins (barley, maize and raw potatoes) and different portions of the starch origins in the rations (50, 25 and 10% of the net energy fat, cattle (NEFr) content of the rations) on the energy utilization of rations a contribution was made to the development of the energetic feed evaluation within Rostock NEF-system. The experiments were carried out with fattened oxen using the methods of total metabolism technique and duodenal passage measurement by means of reentrant fistula. The nutrition levels amounted to 1.7 and 1.1 of energy maintenance requirement. The utilization of metabolizable energy for deposition of the 9 rations-including 3 variants of starch origins barley, maize and raw potatoes with parts in the rations of 50, 25 and 10%--was measured as 65, 61 and 59%, 61, 60 and 58% as well as 59, 61 and 55%. The energy maintenance requirement amounted to 526 kJ ME/kg LM 0.75.d. The gradations of energy utilization are caused by the connection between energy concentration and utilization of rations in ruminants. With comparable parts of the rations the different starch sources had no relevant influence on the energy utilization of the rations. Despite a wide range of starch plus water soluble carbohydrates (WSC) intake between 896 and 3426 g/animal.d no correlation between the kind of digestion (fermentative or enzymatic) of starch and WSC and the energy utilization of the rations was measurable, because the part of the ruminal digestion amounted to 86.0 and 97.2%. The result presented for the energy and nitrogen metabolism measurements are in good agreement with results of former experiments with 92 rations.

Animal Feed↗

PubMed1993

[The energy and nitrogen metabolism of pregnant and lactating sows and suckling piglets. 1. Experimental plan and results concerning the live weight development of pregnant, non-pregnant and lactating sows and the reproductive performance during gestation and lactation].

The aim of the experiments was to work out new results for a factorial derivation of energy and protein requirement. The experiments were carried out according to a 3 x 3 factorial experimental plan with 3 variants of litter number (1, 2 and 4, age of sows) and 3 variants of energy supply (120, 100 and 80% of the norm of pregnancy, continued in lactation with 80, 100 and 120%). Methods of the indirect calorimetry and the slaughtering technique were used. The mean cumulative live weight changes of the sows for the 9 experimental variants amounted from 13.1 to 63.2 kg for the 115 days of pregnancy and from -17.0 to 6.8 kg for the first 26 days of lactation. The chosen variation of energy supply of pregnant and lactating sows had no relevant effect on the reproductive performances, measured by litter size, weight of conception products, litter weight at birth and the quantity of milk per sow and day respectively. In comparison with the sows of litter number 1 the sows of litter number 2 and 4 had higher litter weights at birth and higher milk quantities.

Amino Acids↗

PubMed1993

[The energy and nitrogen metabolism of pregnant and lactating sows and suckling piglets. 2. Chemical composition and energy content of the animal bodies of pregnant, non-pregnant and lactating sows].

The influence of litter number (1, 2 and 4, age of sows) as well as gestation and lactation stage of sows on the chemical composition and on the quantities of protein and fat of their bodies was investigated. The slaughter of 46 pregnant, 18 non-pregnant and 17 lactating sows were carried out at the 1st, 56th, 84th, 98th, 105th and 113th day of gestation, 113th day of experiment (non-pregnant sows) and 26th day of lactation. The results were related to the sows' energy supply (120, 100 and 80%) with equal supply of protein, vitamins and minerals. Within the tested litter numbers the chemical composition of the bodies was nearly constant during the whole time of gestation and lactation. A good agreement existed for the chemical composition of the sows' bodies of litter number 1 and 2. In comparison to them the bodies of litter number 4 contained more protein and less fat per kg dry matter. The quantities of body protein and fat increased in the gestation and decreased in the lactation period, in each case the quantities of fat exceeded than the quantities of protein. The quantities of body protein increased with higher litter number. The quantities of body fat increased from litter number 1 to 2 and were nearly equal in the sows of litter numbers 1 and 4. Within one litter number the amounts of body protein and fat attained the same level in pregnant, non-pregnant and lactating sows.

Animals↗

PubMed1993

[The effect of starch sources barley, maize and potatoes and their ration portions on the nutrient digestibility and energy utilization in ruminants. 4. Nitrogen metabolism in the rumen].

In 9 experimental periods on four adult bulls (LW 550 kg) fitted with re-entrant cannulae in the proximal duodenum isoenergetic rations were used on feeding level 1.7 with ground barley, ground maize or fresh potatoes as starch sources. The net energy parts of these concentrates in the ration amounted to 50, 25 and 10%. 50 to 80% of the ration DM consisted of dried grass and about 10% of sugar beet pulp. The dried grass supplied on an average 87, 79 and 62% of the feed crude protein. The intake of DM was 7.74 +/- 0.42 (mean +/- SD) kg/d. The energetic efficiency of microbial N synthesis in the rumen (g N/kg organic matter true fermented in the rumen, TFOM) was averaged 16.4 with a range of 10.6 to 21.4. The microbial efficiency achieved a maximum when the ratio of nitrogen-free extract to crude fibre in the diet was 1.7 and 2.1 with barley, 1.8 with potatoes and 2.1 and 3.3 with corn as starch source. Changes in the microbial efficiency were positively correlated with the rate of passage of non-microbial organic matter from the rumen (g/d) and with the duodenal flow rate (kg digesta/kg DM intake). The relation to the rate of carbohydrate fermentation in the rumen (in %) and to the amount of TFOM (g/d) was negative. The duodenal flow of microbial N and non-ammonia N (g/d) correlated negatively with the organic matter apparently fermented in the rumen (AFOM) and positively with the non AFOM. The amino acid (AA) profile of the duodenal protein was affected by the starch source. It was concluded that the metabolism of nitrogen in the forestomachs of cattle is affected by the source of starch and the ratio of forage to concentrate. There exists a relationship between both factors. The net synthesis of microbial protein in the rumen is not only the result of substrate fermentation. The passage of non-AFOM from the rumen significantly affects the energetic efficiency of microbial nitrogen synthesis and the duodenal supply of AA.

Amino Acids↗

PubMed1993

Investigations on the influence of Clenbuterol and recombinant porcine somatotropin on nitrogen and energy metabolism in growing pigs.

The effect of Clenbuterol and recombinant porcine Somatotropin (rpST) on the N and energy metabolism was tested by means of the respiration trial technique and compared with a control. In one experiment Clenbuterol was given per os on the nutrition level of three times energy maintenance requirement and in two experiments on the nutrition level 3.2 and 2.4 times energy maintenance requirement, rpST was injected s.c. The live weight gain of the treated animals was 9% (Clenbuterol), 18 and 24% (rpST) higher than that of the controls, protein energy deposition was 21% (Clenbuterol), 45 and 46% (rpST) higher and fat energy deposition was 14% (Clenbuterol), 33 and 37% (rpST) lower than that of the controls.

Aging↗

PubMed1993

[Energy and nitrogen metabolism of pregnant and lactating sows and suckling piglets. 3. Chemical composition and energy content of the animal body fractions as well as portions of the animal body fractions of empty body of nonpregnant, pregnant and lactating sows].

The study is based on the results obtained from the slaughter of 5 sows on the first day of pregnancy and the first day of the experiment respectively (pregnant and non-pregnant sows resp.), of 43 pregnant sows on the 56th, 84th, 98th, 105th and 113rd day of gestation as well as 17 lactating sows on the 26th day of lactation. The animal bodies of pregnant sows were divided in 15 fractions and those of non-pregnant and lactating sows in 12 fractions. The investigations were carried out with 3 x 3 variants of litter number (1, 2, 4) and energy supply (120, 100, 80% of requirement recommendation). The chemical composition and the energy content of the animal body fractions as well as their relative portions of the empty body were largely constant during the course of gestation with the exception of the reproductive organs and the conception products. The physiological stage of lactation connected with limited mobilization of body reserves resulted in a reduction in fat content of some body fractions as well as a limited increase of the portions of body organs contrary to the portions of body tissues of the empty body. In comparison with sows of litter numbers 1 and 2 the sows of litter number 4 were characterized by higher portions of bones and meat, valuable parts as well as by smaller portions of depotfat and meat from head and belly of empty body. The raising of the energy supply of the pregnant sows increased the portion of the depotfat and decreased the portion of the meat, valuable parts of the empty body. The chemical composition of the reproductive organs and the conception products as well as the portions of these fractions of the empty body were influenced strongly from the course of the gestation and lactation resp. The portions of the reproductive organs and of the conception products are small (related to energy < or = 5.7 and < or = 2.6% resp.)

Abattoirs↗

PubMed1992

[The energy metabolism of growing swine in a live weight range of 10-50 kg. 3. Energy maintenance requirement of growing swine].

Investigations into the energy maintenance requirement yielded the following results: For the energy maintenance requirement (EMR) in dependence on live weight (LW) using the relation EMR = aLWb from 13 experiments, an exponent of the live weight of 0.647 +/- 0.054 (0.57 to 0.73) was found out. Increasing the protein content in the feed from approximately 17 to approximately 45% in 6 experiments lowered the energy maintenance requirements about 14, 4, 6, 2, 6 and 12% respectively. The animals' development had no influence on the difference. The amount of the energy maintenance requirement varied greatly between the experiments. Exclusively in the experiments with barrows, a lowest value of 634 and a highest value of 931 kJ metabolizable energy per kg LW0.62.d was measured. On average of 19 comparisons the energy maintenance requirement derived from growth and maintenance periods by means of regression analysis was significant (alpha = 0.05), about 4% higher than the energy maintenance requirement measured on maintenance level directly.

Animal Feed↗

PubMed1992

[The energetic utilization of rations with molasses, dried sugar beets, apple pectin and lucerne leaves by adult swine].

The energetic utilization of 6 rations with molasses, dried sugar beets, apple pectin and lucerne leaves was measured in 8 adult pigs by means of the respiration test technique. The energy digestibility of the rations ranged from 74 to 88%, the partial utilization of the metabolizable energy from 66 to 78%. From the results with apple pectin a mean energy deposition value of 7.2 +/- 12.5 kJ/g digestible pectin was derived. Taking into consideration results from previous recorded experiments and the high standard deviation for estimation of the energetic feed value as deposition effect of digestible pectin, 5 kJ/g are proposed.

Animal Feed↗

PubMed1992

[Effect of the starch sources barley, corn, potatoes and their ration fractions on the nutrient digestibility and energy utilization in ruminants. 1. Comparative studies of nutrient digestibility in cattle and sheep].

Rations with energy parts of 50, 25 and 10% from barley, maize and potatoes were investigated comparatively by means of total metabolism experiments with oxen with a view to arriving at a more precise estimation equation of net energy fat for cattle. Parallel to the investigations with oxen the energy and nutrients digestibility of the rations in wethers was measured. The crude fibre content of the rations ranged from 166 to 271 g and the starch content from 69 to 330 g/kg DM. The daily starch intake of the oxen ranged from 575 to 2739 g on nutrition level (NL) 1.7 and from 365 to 1804 g on NL 1.1. The energy digestibility of the rations in oxen with energy parts of 50% barley, maize and potatoes was on average 73.5, 73.9 and 75.3%, of the rations with energy parts of 25% on average 72.2, 71.6 and 72.4% and of the rations with energy parts of 10% on average 68.8, 69.5 and 69.8%. The digestibility of energy and nutrients in cattle and sheep was in good agreement excepted crude protein and crude fat; these were digested 4-5%-units lower from cattle than from sheep. The increase of the nutrition level by one unit lowered the digestibility of rations with energy parts of 50 and 25% from concentrates in cattle about 3-6 units and of rations with energy parts of 10% from concentrates about one %-unit. Information about rumen physiological data is given comparatively between cattle and sheep.

Animal Feed↗

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↗