Zur Schätzung des energetischen Futterwertes anhand von analytisch bestimmbaren Kriterien

Methane production in cattle calculated by the nutrient composition of the diet

In this study data originating from complete metabolic trials with cattle of both sexes, fed 337 rations at feed intake levels between one to three times maintenance energy requirement were used to regress the total CH4 emission to the level of DM intake and to the nutrient composition, respectively. A major component of the measured CH4 emission cannot be explained by DM intake but is rather due to differences in dietary nutrient composition. The amount of digestible nutrients especially of the carbohydrate fraction (starch, sugar, N-free residuals) are reliable to estimate CH4 release with high precision (r2 = 0.885). Its production rate increased to 1.9-fold higher levels (range 1.8-2.1) per g of N-free residuals compared to that induced per g of protein, starch or sugar, respectively. Furthermore, diets rich in fat reduced CH4 formation in the rumen. The regression equations fit a wide range of diets and diet compositions, and more importantly, they are applicable to various types of production systems.

Inulin alters the intestinal microbiota and short-chain fatty acid concentrations in growing pigs regardless of their basal diet

Inulin stimulates intestinal bifidobacteria in humans and rodents but its effect in pigs is inconsistent. We assessed the effect of inulin on the intestinal microbiota by fluorescent in situ hybridization in growing pigs (age 9-12 wk). Pigs (n = 64) were assigned to 2 types of basal diets [wheat and barley (WB) or corn and wheat gluten (CG)] with or without 3% inulin (WBI or CGI) for 3 and 6 wk (n = 8/group) to test whether naturally occurring dietary fibers influence the inulin effect. Intestinal organic acids, pH values, and residual inulin were determined. The composition of the microbiota was highly individual. The duration of feeding did not affect any of the variables tested; therefore, data for the 2 periods were pooled. Bifidobacteria were detected in less than half of the pigs. Inulin did not stimulate lactobacilli and bifidobacteria numbers irrespective of the basal diet, although 20-50% of inulin was degraded in the jejunum. The number of pigs with colonic bifidobacteria was higher in those fed diets containing inulin (40 vs. 13%; P < 0.05). Total colonic short-chain fatty acid (SCFA) concentrations were lower in both inulin-fed groups due to reduced acetate (P < 0.05). Proportions of colonic butyrate were higher in pigs fed inulin-supplemented diets (P < 0.05). Colonic pH tended to be lower in the WB groups (WB; 6.6 +/- 0.6), and was higher due to inulin (CGI, 7.1 +/- 0.1; P < 0.05). In conclusion, inulin affected intestinal SCFA and the number of pigs harboring bifidobacteria; this effect was independent of the basal diet.

Influence of Nutrition Level on Digestibility in High Yielding Cows and Effects on Energy Evaluation Systems

The objective of the study was to determine the effect of nutrition level (NL, multiples of maintenance energy requirement) on the digestibility of nutrients for dairy cows regarding the energy supply of the animal. The digestion of nutrients and energy was investigated in two trials using lactating dairy cows. The NL varied from 2.7 to 5.0 using diets similar composition. In addition, sheep were given the same feed with a NL of 1.4. Digestibility of dry matter (DM) and all specific measures of dietary components declined significantly as NL increased. Digestibility of energy decreased by 4.1% for each increase in NL. The metabolizable energy, the ability to metabolize energy (metabolizable energy/gross energy), and the content of net energy for lactation (NE(L)) per kilogram of DM intake were calculated for NL from 1 to 6 on the basis of these relationships and as well as the gross energy, methane energy, and urine energy. Accordingly the NEL content declined by 0.11 MJ/kg of DM intake or 1.6% as the NL increased by one unit. It means that the NE(L) requirement above the maintenance requirement increased by 0.07 MJ of NE(L) per kilogram of fat-corrected milk, if the NL increased by one unit.

Energy metabolism of cocks and broiler chickens fed on diets with different carbohydrate sources

Energy balances of cocks and chickens were measured using the nitrogen-carbon-balance method. In Experiment 1 twelve adult White Leghorn cocks were fed alternately on a basal ration or on a supplemental ration composed of 75% basal diet and 25% carbohydrate source as a supplement. In Experiment 2 six groups of 12 male broiler chickens were fed successively on two diets each with different carbohydrate sources (40% of DM) and on two energy levels. The investigated carbohydrate sources were glucose, fructose, sucrose, maize starch, raw and steamed potato starch, dried sugar beet pulp, tapioca, wheat, maize, rye and barley. In both experiments the energy digestibility of the diets with raw potato starch, beet pulp and barley was significantly lower compared to the other diets. Digestibility of those ranged from 88 to 81%. By simple linear regression no significant differences in efficiency of utilisation of ME of the diets between the carbohydrate sources sugars, starches and cereal grains could be proved. The corresponding MEm values agreed very close among the diets (411 to 429 kJ.kg BW-0.75.d-1).

[Energy metabolism in laying hens of different body weight genotypes]

Energy metabolism and some performance parameters were investigated in laying hens of 3 different body weight-genotypes: 6 x 7 (normal-sized, crossbred from normal-sized male and female lines, group 1), 47 x 38 (dwarf-sized, breeding from a dwarf-sized male line and a normal-sized female line, group 2) and 44 x 47 (dwarf-sized, breeding from dwarf-sized male and female lines, group 3). Energy balance was measured by indirect calorimetry through C- and N-balances in 12 animals of each group during 10 consecutive days at production peak, within the period between the 27th and the 37th week of age. Hens were caged individually at 23 degrees C environmental temperature and fed ad libitum on a laying mash. The mean body weight in the dwarf-sized groups 2 and 3 was 32% lower than in the normal-sized group 1 during the energy balance period. The daily gross energy intake in group 2 and 3 was decreased by 33 and 34%, respectively. There were no significant differences in digestibility and metabolizability of gross energy between the groups. The energy requirements for maintenance [kJ ME/kg0.75.d] derived from the energy balances were lower by 4% (P > 0.05) and 14% (P < 0.05) in the dwarf-sized groups 2 and 3 as compared with the normal-sized group 1, when equal coefficients of partial efficiency of metabolizable energy utilization for energy retention in body and eggs are assumed for the 3 body-mass genotypes. There were no relevant differences in body composition at the end of the energy balance periods as well as in egg composition between the 3 experimental groups.

[Results from measurements of nitrogen and energy metabolism in adaptive different cattle]

In experiments with Galloway (G), Highland (H) and Black-White Dairy (B) cattle no significant differences between the breeds were measured in the energy and nutrient digestibility and energy metabolizability of rations with high variation in the nutrient composition. In H and B cattle no differences existed in digestibility in relation to the environmental temperature (30, 18 and 3 degrees C). Lowering the environmental temperature from 18 to 12 and 4-6 degrees C resulted in no changes of heat production in G and H but in B heat production increased about 6% and 20% respectively.

[Effect of the convertibility of energy (Q) on energy maintenance requirement and utilization and convertible energy for the assessment of ruminants. 1. Digestibility of energy and nutrients]

The energy metabolism was measured by means of indirect calorimetry in growing bulls with mean live weights of 290-420 kg and in wethers with mean live weights of 40-60 kg. The animals were fed 12 (bulls) and 8 rations (wethers) with high variation in the nutrients composition and with a range of energy metabolizability (q) between 0.74 and 0.47 on 3 steps of nutrition level (deposition, maintenance, underfeeding) as a rule. The energy digestibility of the 12 rations tested in growing bulls on the nutrition level maintenance was measured between 81.9 and 56.4% and that of the 8 rations tested in wethers was measured between 82.6 and 55.6%. On the high and middle nutrition levels the data of energy and nutrients digestibility in growing bulls and wethers were in good agreement, except the significant lower digestibility of crude protein in cattle. On the low nutrition level digestibility of energy, crude protein, crude cellulose and N free residual substances in wethers was 3-5 digestibility units lower than in bulls. The increase of nutrition level by 1 unit lowered the energy digestibility in bulls by 4.2 and the nutrients digestibility about 4-8%-units (0.7 for starch). In sheep the effect was not so high as in cattle. There were differences in the rumen physiological parameters between the animal species. In the growing bulls' rumen liquid the part of acetate was higher and the parts of propionate and butyrate were lower. The content of NH3 was higher in sheep. The increase of nutrition level caused higher amounts of volatile fatty acids in the two animal species with lowering the part of acetic acid and raising the parts of propionic and butyric acid.

[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]

[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]

[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.

[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.

[Effect of exogenous factors on prececal nutrient and amino acid reabsorption, ascertained in swine with ileorectal anastomoses. 1. Effect of the degree of grinding up of grain]

Pigs fitted with ileo-rectal anastomoses (IRA) and in parallel experiments intact (INT) pigs were used to estimate the influence of the different grinding fineness of barley and wheat (coarse, medium, fine) on the apparent and true precaecal and total digestibility resp. absorption of various N free and N containing nutrients, among them crude protein and the indispensable and dispensable amino acids. Coarse grinding (25 ... 50% of the particles greater than 2 mm) resulted in significantly lower digestibility values than medium and fine grinding--with more striking differences in barley than in wheat. Precaecally most nutrients and amino acids are distinctly less digestible than at the end of the total tract. The precaecal lysine absorption determined with IRA pigs is remarkably low. The results are discussed. In order to attain a good utilization of the protein contained in cereals grains should be ground in hammermills with maximal sieve meshes of 3 mm. It is proposed to tabulate crude protein and amino acids in future on the basis of a standardized true precaecal digestibility resp. absorption.

[Effect of thermal treatment of potato products on nutrient decomposition in the digestive tract of swine. 2. Nutrient content and bacterial activity in various parts of the intestine]

Dry matter (DM), starch, crude protein (CP), amino acids (AA) and diaminopimelic acid (DAPA) were estimated in the contents of the digestive tract of slaughtered pigs, which were fed a basal diet with raw (rKSt) or with cooked (QuSt) potato starch. When fed rKSt, there was larger quantities of starch and DAPA in the content of the distal small intestine and also of DM, CP, AA and DAPA in the contents of caecum and proximal colon, compared to QuSt. The bacterial breakdown of the raw potato starch granules in the proximal large intestine is shown by microscopic examinations. It is suggested, that the quantity of bacterial protein excreted in the faeces did not allow to quantify the extent of the bacterial activity in the different segments of the digestive tract.

[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)

[Methodologic studies of ileal flow measurement using large lumen intestinal cannulae in swine]

A special operation method and intestinal cannulae were developed for the ascertainment of the ileal nutrient digestibility of roughage and root crops. The presented method has proved reliable over a period of 2 years. The possibility of ascertaining the chyme flow directly (by total collection) or indirectly (with an inert marker) is described. The reduction of the expenditure of labour by cutting down the collecting period is suggested for routine studies.

[Protein and amino acid metabolism in the digestive tract growing young bulls. 1. Flow of bacterial raw protein in the duodenum determined by 2,6-diaminopimelic acid as a marker]

The influence of the composition of the rations on the content of diamino pimelic acid (DAP) and N in the bacteria dry matter and on the flow of bacteria crude protein into the duodenum, determined with DAP as marker, was determined on the basis of experimental investigations with young bulls provided with duodenal cannulae and with 28 different rations whose details are described. At a production level corresponding to dry matter intake and a variation range of the crude fibre content of between 11.3 and 29.1% in the DM, a content of N-free extractives between 50.9 and 77.4% in the DM, a content of soluble carbohydrates ibetween 5.3 and 6.4% in the DM, a crude protein content of between 6.4 and 17.1% in the DM and a pure protein content of between 4.9 and 15.5% in the DM, the DAP content of the bacteria DM amounts the 0.350 g 100 g DM +/- 0.090 the N-content of the bacteria DM amounts to 7.37 +/- 1.08 g/100 g DM, there are no relations between DAP- and N-content in the bacteria DM and the content of the individual carbohydrate fractions of the ration, there are positive relations between DAP- and N-content of the bacteria DM, the flow of bacterial crude protein into the duodenum amounts to 133 +/- 14 g/kg truly fermentable organic matter or 130 +/- 14 g/kg apparently digestible organic matter, there is a negative relation between bacteria crude protein at the duodenum (BCPD)/kg truly fermentable organic matter and the crude fibre content of the ration, there is a positive relation between BCPD/kg truly fermentable organic matter and N-free extractives and soluble carbohydrate content as well as the digestibility of the organic matter of the ration, there is no specific influence of the flow rate (kg digesta/kg intake of org. matter) or the dilution rate (g bacteriafree org. matter D/kg LW075/b) on BCPD/kg truly fermentable org. matter, there is a dependence of BCPD/kg truly fermentable org. matter on crude protein concentration in the ration in the concentration range of 6.4-9.0% crude protein in the ration (provided endogenous CP equivalents are used).

[Proposal for an efficient crude fiber determination in routine analysis]

On the basis of the method described in the standard TGL 21875/07--method II in GDR--and proved effective in practise, a rationalised method of the determination of crude fibres has been worked out. This method is described in detail; it makes greater than 60 individual determinations of crude fibre per worker and day possible. In contrast to the conventional determination of crude fibres (standard 21875/07--method I) this method is more efficient and its degree of standardisation is considerably higher. The results achieved on the basis of the conventional method of the determination of crude fibres (standard TGL 21875/07--method I Lepper-method) and the suggested method of determination with various feedstuff samples at the Zentralstelle für Futtermittelprüfung und Fütterung (Central Institution for Feedstuff Investigation and Feeding) Halle-Lettin and Department of Animal Nutrition of the Forschungszentrum für Tierproduktion (Research Centre for Animal Production) Dummerstorf-Rostock show that there are no statistically significant differences between the crude fibre values ascertained according to the two methods. Method II of the standard TGL 21875/07 should be replaced by the suggested method of determination because this method directly registers the crude fibre content.