The apparent precaecal crude protein digestibility and amino acid absorption as well as the total digestibility of the nutrients organic matter, crude protein, crude fat and crude carbohydrates were determined of rations consisting of barley plus oilmeals of two rapeseed varieties of double quality (DQ) from Canada (Canola) and the GDR as well as of one variety of single quality (SQ) with 10 female pigs weighing between 120 and 140 kg with ileorectal anastomoses (IRA) and 4 intact (INT) female pigs weighing between 150 and 160 kg. The three rapeseed meals (RSM) were furthermore fed to IRA pigs as sole protein source together with protein-free feed. Based on the digestibilities of the crude nutrients determined with INT pigs and calculated with the difference method the energy content of RSM DQ "Canola", DQ GDR and SQ GDR could be calculated as 495, 633 and 500 EFU(pig)/kg DM (average: 543 EFU(pig)). The precaecal digestibility of the crude protein of the above mentioned RSM sorts determined with IRA pigs and calculated with the difference method amounts to 73, 76 and 75 % resp. and is thus lower than the average absorption of all amino acids. The precaecal digestibilities of crude protein and essential amino acids for the mixtures calculated from the digestibility values of the individual feedstuffs barley and the above mentioned RSM largely agree with the experimentally determined digestibility values, i.e. there is additivity. On an average of the values known from literature for DQ RSM (including our own results), the precaecal digestibility of crude protein amounts to 70, of lysine to 74, of methionine to 82, of cystine to 82, of threonine to 69, of tryptophan to 72 and of isoleucine to 74 %.

: The apparent precaecal (pc) digestibility of crude protein (CP) and the apparent pc absorption of the key amino acids (AA) lysine, methionine, cystine, isoleucine, threonine and tryptophan from two yellow sweet lupine (L. luteus) varieties (Bornova, Borluta) and one narrow-leafed sweet lupine (L. angustifolius) were determined with ileorectostomized pigs. When the influence of the basal diet (barley or protein free rations) was checked with regard to absorption there were significant differences in a few cases only. In comparison to soybean meal (SBM) the methionine of the lupines was significantly worse, the cystine significantly better absorbed. The CP and the other key AA of the lupines showed approximately the same or even slightly higher pc absorption than those of SBM. With the example of the pc-absorbable AA amounts it was shown that sweet lupines with an approximately equally high CP content as in SBM cannot completely substitute the latter even after lysine and methionine supplementation because the absorbable tryptophan is by far insufficient, and isoleucine and threonine make up only 75% in comparison to SBM. On the basis of the content of pc-digestible CP and pc-absorbable AA it becomes possible to substitute high-grade imported protein concentrates according to their ability of AA supply in the feeding of pigs completely or partly by home-made protein feeds.

The objective of this study was to explore whether the C and N content can be used to estimate the fat content of animal carcasses. Considering the mean C and N contents of body fat and body protein, the fat content (EE) [%] can be predicted from C and N values [%] according to the generally valid equation EE = 1.3038 x C - 4.237 N. The application of this equation to estimate the total fat content of all animal carcasses results in significant differences in fat content between predicted and measured values. Therefore, we derived specific equations for rats, pigs, cattle, sheep, broilers and mice to predict the fat content by dual linear regression analysis (y = EE [% DM], x1 = C [% DM], x2 = N [% DM]) based on measured fat, C, and N contents of animal body samples. The specific equations for different animals showed residual standard deviations of 1.55, 1.63, 1.12, 1.35, 1.85 and 0.92% fat for rats, pigs, cattle, sheep, broilers and mice, respectively.

At the time of weaning, major quantitative and qualitative changes occur in the composition of the intestinal microbiota of piglets, influenced by diet, environmental factors, and the host. Within a short period of time, the intestinal microbiota must ultimately develop from a simple, unstable community into a complex and stable one. Here we present data on the development of the intestinal microbiota based on 16S rRNA gene sequence diversity. In addition to a PCR-based analysis of the 16S rRNA gene by cloning and denaturing gradient gel electrophoresis (DGGE), data on fluorescent in situ hybridisation ( FISH) are presented to quantify the total bacterial communities, major Lactobacillus populations and specific Lactobacillus species. The results reported here indicate that the addition of non-digestible, fermentable carbohydrates (= prebiotics) leads to an enrichment of lactobacilli in the small intestine, and increased stability and diversity of the bacterial community in the colon. The data support the hypothesis that changes of the diet can modulate the composition of the microbiota in the intestine. These findings may have potentially major implications for the development of dietary strategies aiming to improve animal health during the weaning process.

The work aimed to determine the apparent and true ileal digestibility of the amino acids of tropical tree foliage (Trichanthera gigantea) or aquatic plant (Azolla filucoides) in pigs. The incorporation of 100 or 200 g/kg of either tree foliage or aquatic plant in the pig diet significantly reduced both ileal and fecal digestibilities of the dietary nitrogen and amino acids of the diets (P < 0.05). The results are discussed according to the pig digestive physiology and the forage properties.

To characterize ileal microbial flora in weaning piglets a slaughter trial was conducted. 384 German Landrace piglets of both genders were allocated to four different feeding regimes (with/without antibiotic; 3% or 8% crude fibre content). Pre- and postweaning piglets were sacrificed at defined times, the whole intestinal tract was removed and its content collected, for each section separately.The microbial community was examined applying classical plate counting (selective agar plates) and molecular techniques (DGGE, 16S rDNA-sequencing, FISH). Furthermore a range of microbial metabolites was determined. Pre- and postweaning alterations in the microbial community of the small intestine - rather due to age than to diet - were observed.

Results of respiration trails, including complete protein (amino acids) and nutrient balances, with two strains of high productive laying hens (Lohmann BROWN and Lohmann LSL) were described with recommendations and conclusions for requirements and feeding strategies.

Dietary fibre is defined as a heterogenous mixture of structural and non-structural polysaccharides and lignin. A large number of investigations have been carried out to study the effect of dietary fibre on digestibility and endogenous losses in pigs. Most of the authors reported that fibre content of the diet can impair apparent ileal digestibility of dietary nutrients, endogenous nitrogen and amino acid secretion and losses. Investigations during the last few years have shown that the effects of dietary fibre differ with the source and nature of fibre and relate to their chemical composition as well as to their physico-chemical properties. The effect of pure cellulose is rather low in contrast to other types of fibre (i.e. hulls, bran, endosperm fibre or pectin). In experiments, the endogenous nitrogen losses were almost twice as high after feeding barley endosperm fibre as compared to barley hulls (331 versus 180 mg N per 100 g dry matter intake (DMI)). It is difficult to ascertain which physical or chemical properties are responsible for the effects. The data presented in the review illustrate that dietary fibre solubility, viscosity and water-holding capacity seem to be the most important factors influencing ileal digestibility of nutrients and endogenous losses in pigs. The latter is also affected by protein level of the diet and protein sources.

Ileal endogenous N losses (ENL) were measured, using the15N isotope dilution technique, in piglets (17 kg) fed different barley genotypes (naked, spring, winter with low/high beta -glucan content) or diets containing 330, 530, 730 or 930 g of a blend of barleys/kg diet. The apparent protein and amino acid digestibilities of the naked variety and the winter variety with a high beta -glucan content were, on average, significantly higher than those for the other two varieties. The ENL were inversely correlated (p<0·01) with the apparent digestibilities but the difference between each of them was not significant (p>0·05). The ENL increased linearly with the inclusion level of barley in a N-free basal diet (2 mg endogenous N/g barley). Isolated hulls added to a N-free diet at the rate of 100 or 200 g/kg diet exerted no significant effect on the ENL (1·80 g endogenous N/kg diet in both cases vs. 1·76 g for the basal level). On the contrary, the effect of isolated bran, measured under similar conditions, was significantly higher and dependent on fibre intake (2·59 and 3·31 g N/kg diet, respectively). It is concluded that the ENL are affected by the insoluble bran fibre but not by the hulls, nor by the level of beta -glucan.

Summary Protein turnover, efficiency of growth and body composition were investigated in N balance experiments with growing male mice (26‐36 days of age) which were long‐time selected for high carcass protein amount (DU‐6P) or for high body weight (DU‐6) and in the unselected randomly bred control (DU‐Ks). In total 12 mice per line were housed singly in metabolic cages and had free access to a commercial stock diet (crude protein 267 g, gross energy 19 MJ/kg dry matter). N balance, whole body protein synthesis (PS, end‐product method, single dose of 15 N‐labelled amino‐acid mixture), fractional myofibrillar muscle breakdown rate (FBR, 3‐methylhistidine method) and N distribution in the body were measured. Additionally, the maintenance nitrogen requirement (MNR) and the maximum possible rate of N accretion (MNA) of the different lines was estimated after feeding semi‐synthetic diets with increasing protein levels. Body weight of both selection lines was about twice that of the control mice at the same age. The DU‐6P mice synthesized and deposited more protein and less fat per unit metabolic BW, than the DU‐6 mice did. However, scaled to the corresponding body protein pools, the rates of protein synthesis were not significantly different between both selection lines in contrast to the deposition rate. Selection for high body weight resulted in higher body fat content, higher muscle FBR and a lower proportion of carcass N compared to DU‐6P mice. The protein synthesis (13‐14 g protein/kg BW 0.75 per day) and MNR values (290‐305 mg N/kg BW 0.75 per day) of the selected mice were higher than those of control mice (11 g protein and 265 mg N/kg BW 0.75 , respectively) and may be due to selection‐linked enlargments of visceral organs. The MNA of DU‐6P and DU‐6 mice amounted to 6 and 5 g protein/kg BW 0.75 , respectively, and the MNA of the controls was between these values. Compared to DU‐6, the higher protein accretion rate of DU‐6P mice seems to be due more to a lower muscle protein breakdown rate than an increased protein synthesis rate. Zusammenfassung Proteinumsatz von Mäusen, die auf hohen Körperproteingehalt oder auf hohes Körpergewicht selektiert wurden An je 12 wachsenden männlichen Mäusen, die über 80 Generationen am 42. Lebenstag entweder auf hohen Proteingehalt im Schlachtkörper (DU‐6P) oder auf hohe Lebendmasse (DU‐6) selektiert worden waren, wurden Proteinstoffwechsel, Wachstumseffizienz und Körperzusammensetzung im Vergleich zur unselektierten Kontrollinie (DU‐Ks) untersucht. Die Tiere wurden einzeln in Stoffwechselkäfigen bei freiem Zugang zu Wasser und Altromin‐Zuchtfutter (Rohprotein 267 g/kg TS, Bruttoenergie 19 MJ/kg TS) gehalten. Neben der N‐Bilanz wurden Gesamtkörper‐Proteinsynthese (PS, Endproduktmethode, einmalige Gabe einer 15 N‐Aminosäurenmischung, Auswertung mittels Kompart‐mentmodell), fraktionelle Muskelprotein‐Abbaurate (FBR, 3‐Methylhistidin‐Methode), Verteilung des Körperstickstoffs, N‐Erhaltungsbedarf (MNR, regressiv nach Fütterung semi‐synthetischer Rationen mit steigenden Proteinniveaus) sowie maximales N‐Ansatzvermögen (MNA) der Mauslinien gemessen. Die mittleren Lebendmassen (LM) der selektierten Tiere waren bei gleichem Alter etwa doppelt so hoch wie die der unselektierten Kontrolle. Pro kg metabolischer LM synthetisierten und deponierten DU‐6P‐Mäuse täglich mehr Protein als DU‐6‐Mäuse. Bei Bezug auf die entsprechenden Körperprotein‐gehalte waren die Unterschiede in den täglichen Proteinsyntheseraten beider Selektionslinien im Gegensatz zur Proteinansatzrate nicht mehr signifikant. Die Selektion auf hohe LM (DU‐6) führte zu höheren Körper‐Fettgehalten, zu höheren FBR und damit zu niedrigeren Körper‐N‐Gehalten im Vergleich zur Selektion auf hohen Proteingehalt (DU‐6P). Proteinsynthese (13–14 g Protein/kg LM 0.75 .d) und MNR (290–305 mg N/kg LM 0.75 .d) der selektierten Mäuse waren höher als die der Kontrolltiere (11 g Protein bzw. 265 mg N/kg LM 0.75 .d) und können mit den selektionsbedingten Vergrößerungen der relativen Organgewichte zusammenhängen. Die MNA‐Werte lagen zwischen 5 (DU‐6) und 6 g (DU‐6P) Protein/kg LM 0.75 .d. Der im Vergleich zur Linie DU‐6 höhere Proteinansatz der DU‐6P‐Tiere scheint mehr durch eine verminderte Muskelprotein‐Abbaurate als durch eine höhere Proteinsyntheserate bedingt zu sein.

Five pigs were each surgically prepared with end-to-side (E.t.S.) and end-to-end (E.t.E.) ileorectal anastomoses (IRA). The ileo-caecal valve was preserved in both modifications. The animals were fed diets with maize or solvent extracted oil seed meals from sunflower, cottonseed, linseed or soybean and maize in combination with one of these oil seed meals. The aim of the experiment was to estimate the influence of both IRA-techniques on the precaecal nutrient digestibility and amino acid (AA) absorption. The crude carbohydrate digestibility in two of the five single protein diets and in three of the four blends were significantly higher in the E.t.S.--than in the E.t.E.--IRA group. There were no significant differences between the two IRA-modifications in crude protein (CP) and crude fat digestibility. No differences were observed in AA absorption for the single components maize, sunflower- and cottonseed meal. The absorption values of isoleucine, leucine and valine from linseed meal were significantly more than 5%-units higher in the E.t.S.-group than in E.t.E.-animals. There were similar results in soybean meal for four essential AA but with differences below 5%-units. Accordingly the two IRA-modifications did not influence the AA absorption to a practically important extent.

Five pigs were each surgically prepared with end-to-side (E.t.S.) and end-to-end (E.t.E.) ileorectal anastomoses (IRA). The ileo-caecal valve was preserved in both modifications. The animals were fed diets with maize or solvent extracted oil seed meals from sunflower, cottonseed, linseed or soybean and maize in combination with one of these oil seed meals. The aim of the experiment was to estimate the influence of both IRA-techniques on the precaecal nutrient digestibility and amino acid (AA) absorption. The crude carbohydrate digestibility in two of the five single protein diets and in three of the four blends were significantly higher in the E.t.S.--than in the E.t.E.--IRA group. There were no significant differences between the two IRA-modifications in crude protein (CP) and crude fat digestibility. No differences were observed in AA absorption for the single components maize, sunflower- and cottonseed meal. The absorption values of isoleucine, leucine and valine from linseed meal were significantly more than 5%-units higher in the E.t.S.-group than in E.t.E.-animals. There were similar results in soybean meal for four essential AA but with differences below 5%-units. Accordingly the two IRA-modifications did not influence the AA absorption to a practically important extent.

The apparent precaecal nutrient digestibility and amino acid (a.a.) absorption of 10 diets were estimated in pigs with end-to-side ileorectal anastomoses (IRA) as well as with ileocaecal re-entrant cannulae (IZB). The digestibilities of organic matter and crude carbohydrates were significantly higher in IRA pigs than in IZB pigs in two resp. three diets only. There were no practical important differences for the digestibilities of crude protein and crude fat in all diets. Out of the 180 a.a. absorption comparisons only 20 (i.e. 11%) showed differences larger than 5%-units. The absorption rates of several a.a. were lower in IRA than in IZB pigs and of some other a.a. on the contrary. The methionine absorption of five legume diets and one barley + lysine diet were up to 15% resp. 4%-units lower in IRA pigs. Possibly this was due to the activity of microbes in the rectum in connection with a small intake level of protein bound methionine. In order to minimize such a falsification it is proposed to use the end-to-end anastomosis. The deviations in the apparent a.a. absorption between IRA and IZB pigs can be explained partly by differences in the quantity of precaecally excreted endogenous a.a. per 100 g DM intake.

In a series of experiments in two ileo-rectostomized pigs the precaecal apparent and true digestibilities for crude protein of seven 15N-labelled feedstuffs were studied using the mobile bag technique. True digestibility values of crude protein calculated with the help of isotope dilution were 4-14 units higher than the corresponding apparent digestibility values. This is caused by the infiltration of the bag residues with endogenous unlabelled nitrogen. In dependence on the kind of feedstuff the endogenous N portion in the bags amounted to 25-70% of the total N. In addition, the contamination is influenced by differences between the animals (mean 4-7%) and by different treatments of bags after gut passage (3-10%).

The mobile bag technique (MBT) was used in two ileorectostomized and two intact pigs with duodenal cannulae, in order to estimate the precaecal and total crude protein digestibility and amino acid (lysine, methionine, cystine, threonine, tryptophan) absorption of ten single feedstuffs (field bean, lupin, rapeseed meal, fish meal, barley, wheat) and three diets. For each feed 36 bags were applied per animal. After a peptic predigestion in vitro, application of the bags through the duodenal cannula into the intestine and their passage through the gut, the residues remaining in the bags were pooled to collective samples and just as the original feed material analysed on dry matter, nitrogen and amino acids. The directly determined MBT-digestibilities (BV) and the values obtained by regressive calculations (BVb) have been compared with apparent digestibilities (sV) conducted from conventional digestion experiments. 74 per cent of all BV data was higher than the corresponding sV values. Similarities of BV with sV showed in 58 per cent, those of BVb with sV only in 17 per cent. In all cases differences of > +/- 4 digestibility units showed. Checking additivity of diet-BV by means of calculations from the BV of their single ingredients did not generally lead to the same results as the directly estimated diet-BV; in some cases the results were contrary. Therefore the use of MBT for mixed feed diets has to be further investigated. For single feedstuffs the MBT can be used successfully as a rapid and simple technique when regressive calculations are employed.

The mobile bag technique (MBT) was used in two ileorectostomized and two intact pigs with duodenal cannulae, in order to estimate the precaecal and total crude protein digestibility and amino acid (lysine, methionine, cystine, threonine, tryptophan) absorption of ten single feedstuffs (field bean, lupin, rapeseed meal, fish meal, barley, wheat) and three diets. For each feed 36 bags were applied per animal. After a peptic predigestion in vitro, application of the bags through the duodenal cannula into the intestine and their passage through the gut, the residues remaining in the bags were pooled to collective samples and just as the original feed material analysed on dry matter, nitrogen and amino acids. The directly determined MBT-digestibilities (BV) and the values obtained by regressive calculations (BVb) have been compared with apparent digestibilities (sV) conducted from conventional digestion experiments. 74 per cent of all BV data was higher than the corresponding sV values. Similarities of BV with sV showed in 58 per cent, those of BVb with sV only in 17 per cent. In all cases differences of > +/- 4 digestibility units showed. Checking additivity of diet-BV by means of calculations from the BV of their single ingredients did not generally lead to the same results as the directly estimated diet-BV; in some cases the results were contrary. Therefore the use of MBT for mixed feed diets has to be further investigated. For single feedstuffs the MBT can be used successfully as a rapid and simple technique when regressive calculations are employed.