The prececal and total intestinal nutrient digestibility and amino acid absorption of food yeasts in swine

In a difference experiment the apparent precaecal (pc) and total intestinal (tot) nutrient digestibility and amino acid (AA) absorption of 5 yeasts (n-alkane yeasts Fermosin and Paprin, molasses/molasses distillers residue yeast, two sulfite waste liquor yeasts) were studied. The two n-alkane yeasts were very highly digested pc, the difference to tot digestibility is only small in most cases. In contrast to this, the pc and tot digestibility values of molasses/molasses distillers residue yeast differed considerably more. The probable reason for this is too hot drying due to which pc digestibility, particularly of the crude protein, and pc AA absorption are considerably reduced. In the two sulfite waste liquor yeasts, sulfite waste liquor residues containing lignin impair especially the crude carbohydrate digestibility and the energetic feed value; the better processing conditions of origin A, however, reduced considerably the negative effects. The results confirm that each yeast origin has its specific particularities, which have to be taken into consideration when they are used in feeding.     

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.     

Physiologic nutrition studies in swine with ileorectal anastomoses. 2. The effect of nourseothricin on nutrient digestibility, amino acid absorption, protein utilization and mineral balance of a rye diet

The supplement of nourseothricin (NT) to a rye diet did not have an influence on the precaecal and total apparent digestibility of the crude nutrients or the total digestibility of the amino acids (AA). NT produced significantly higher absorption of some AA in pigs with ileo-rectal anastomoses (IRA) which were orally supplied with electrolyte solution (ES). In general, IRA pigs showed the same results with regard to precaecal apparent AA absorption influenced by the AA pattern of endogenous protein as pigs with ileal cannulae. Functions in the large intestine seem to be important for the effect of NT supplements, as NT supplements to the diet of intact animals tendentially had a positive effect on N, Ca and P balances, IRA animals, however, showed a contrary effect. In comparison with the intracaecal infusion of ES, the oral supply of the IRA pigs resulted in higher N, Ca and P balances. The level of N utilization (N balance in % of the digested N) of the IRA pigs supplied orally was equally high as that of the intact animals (both groups without NT). As derives from literature and the available N, Ca and P balances--significantly influenced by ES supplements--an additional supplement of rations poor in crude fibres of 1 g Na/animal and day seems sufficient for covering the requirement of IRA pigs of a weight of 30...40 kg. After 18 days a P supply below the requirement resulted in a significantly reduced P level (inorganic) in the serum in both animal groups, with the level of the IRA pigs being significantly below that of the INT animals. For this reason, the P requirement of fattening pigs should be fully covered in experiments with IRA pigs. Although the IRA pigs supplied caecally with ES showed typical appearances of Na deficiency, their Na level in the serum did not differ from that of the other animals.     

The effect of exogenous factors on prececal nutrient and amino acid absorption, ascertained from swine with ileo-rectal anastomoses. 3. The effect of crude fiber-rich coarse meal supplements to a basic ration

In digestion trials using pigs fitted with ileo-rectal anastomoses and parallel intact pigs the influence of wheat straw meal (WSM) or grass meal (GM) supplemented on two different levels to a basal diet was examined with regard to nutrient and amino acid digestibility resp. absorption. Both roughages reduced, obviously because of their high cell wall contents, nearly at equal amounts and partly significantly the precaecal as well as the total digestibility of dry matter, organic matter, carbohydrates (= crude fibre + NFE), crude fibre and hemicelluloses (arabinose, xylose). By the roughage supplementations the crude protein digestibility at the terminal ileum was less reduced than at the end of the total digestive tract, the starch digestibility was hardly influenced and that of ether extract mostly increased. In comparison with precaecal glucose and fructose digestibilities it could be shown that the anthrone method is not suitable for determinations of the precaecal digestibility of water soluble carbohydrates. Beside these compounds other substances in the ileum digesta must evidently be dyed by anthrone too. The crude protein digestibility and the amino acid absorption were precaecally hardly or not reduced by WSM supplementations, therefore it can be concluded that it is possible to dilute the energy concentration in diets (e.g. for sows) by addition of WSM without impairing protein digestion and amino acid absorption. The GM supplementations, however, impaired protein digestibility and amino acid absorption of the whole diet, probably caused by the encrusted, possibly heat damaged protein present in the GM itself. When the roughage supplemented diets were fed, the excretion of nitrogen compounds in the faeces was enlarged due to the more intensive bacterial activity in the hind gut and the additional sorption effects to cell wall substances, so that a too low apparent and also true digestibility is made believe. The applicability of the difference method to the calculation of protein and amino acid digestibilities in roughages is very questionable because of their low contents and the missing additivity. The crude fibre and hemicellulose digestibility values calculated by the difference method demonstrate for the both roughages--in spite of high standard deviations--that the precaecal digestibility of crude fibre is about zero and that of the hard lignified hemicellulose fraction in contrast to the predominantly endospermic hemicelluloses of the basal diet is very low. The faecal crude fibre and hemicellulose digestibilities of WSM--especially on the lower supplementation levels--are markedly worse than those of GM.     

The apparent prececal and fecal crude protein digestibility and amino acid absorption of coarse animal feed in fattening pigs

Digestibility experiments were made with nearly full-grown female fattening pigs supplied with large-scale T-cannulae implanted in the distal ileum to collect the digesta in order to test 11, mainly dried and pelleted, kinds of forage plants (9 samples of lucerne cut at different times as well as green rye and whole plants of maize) as supplements to a basic diet. All samples were analysed to their content of HCl-insoluble ash as marker and their content of amino acids (AA). The calculation of the apparent precaecal and faecal crude protein (CP) digestibility and of the absorption values of the essential AA lysine, methionine, cystine, isoleucine, threonine and tryptophan as well as of glutamic acid was carried out according to the difference method. CP digestibility of the experimental diets was precaecally reduced by 5 to 20 and faecally by 3 to 13 units by supplements of at least 25% of the dry matter; for some of the AA the reduction was even bigger and dispersion between the values of the individual animals was essentially increased in comparison with the basic ration. Faecally, the precaecal differences of CP digestibility and AA absorption caused by the various alfalfa samples, are largely blurred. The CP and AA digestibility of the forage plants partly showed very big individual differences between the animals. Precaecally, a CP digestibility of more than 48% could not be ascertained. Similarly to the lysine content, precaecal lysine absorption from the kinds of roughage showed big differences. Whereas the absorption values for methionine of between 60 and 87% were relatively high, those for cystine were mostly very low, often in the negative range. This underlines that normal digestion processes are strongly influenced by high supplements of forage plants so that the constancy of the digestibility of the basic ration must be doubted under these conditions. The bacterial processes in the large intestine greatly level out the differences found precaecally between the various kinds of feedstuffs. The faecal digestibility and absorption values were considerably above those measured precaecally; methionine digestibility only was mostly considerably diminished in comparison with precaecal values due to synthesis in the large intestine. A significant positive correlation could be calculated between the lysine content of the 9 alfalfa samples (4.0 to 6.6 g/16 g N) and the apparent precaecal values of lysine absorption (2.2 to 67.6%).(ABSTRACT TRUNCATED AT 400 WORDS)     

Comparison of the prececal protein digestibility of feed in swine using an "in vitro method"

In vitro determination of protein digestibility by treating feedstuffs with pepsin-HCl yields results that differ considerably from the precaecal protein digestibility figures. Comparable results were received when the largest polypeptides in the solution obtained after peptic und tryptic treatment were precipitated with CuSO4 + NaOH.     

Prececal protein and amino acid digestibility and total crude nutrient digestibility of extracts of three rapeseed varieties, ascertained in ileorectostomized and intact swine

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 EFUpig/kg DM (average: 543 EFUpig). 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%.     

Prececal crude protein digestibility and absorption of amino acids from lupines in swine

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 use of the mobile bag technique in swine. Determination of the apparent crude protein digestibility and amino acid absorption of feed and rations]

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.     

Total amino acid level affects the results of standardized ileal digestibility assays for feed ingredients for swine

It has been demonstrated that the fiber content of oilseed meals and total amino acids(AA) in distillers’ grains products affects standardized ileal digestibility(SID) values from swine assays and that total protein concentration affects the AA digestibility in assays using chickens. This analysis was conducted to test the hypothesis that the total AA content of test samples affects the SID assay results. Databases containing total AA profiles and SID values of 20 feedstuffs commonly fed to pigs...     

Nutrition physiologic studies of swine with ileorectal anastomoses. 1. Surgical method, biochemical and morphologic findings

For the purpose of studying nutrient digestion and absorption in the small intestine, pigs were provided with ileo-rectal anastomoses. The anaesthetic and operation method is described. X-ray examinations do not show a significant backflow of digesta into the from colon cranially open towards the anastomosis as well as a totally intact sphincter ani. With the help of additional doses of highly digestible, N-free nutrients rich in energy (starch + saccharose), the operated animals achieved a growth development corresponding to that of intact control animals. For the assessment of the physiologic state of the animals, the concentrations in the serum of the total protein, of albumin, urea, glucose, calcium, inorganic phosphorus and creatinine as well as the activities of aspartate amino transferase and alkaline phosphatase were determined. These showed for the respective criteria changes conditioned by age and dependent on feed intake. The fixing of the anastomoses did not result in disturbances of nutritional or organic damages. Histologic studies of the mucosa of stomach, duodenum and jejunum did not show pathologic changes. The weight of stomach, duodenum and jejunum, determined in 2 live weight ranges, is identical for operated and intact animals in relation to the weight of the empty body of the animals. The weight of ileum, caecum and colon of the operated animals is significantly lower, due to inactivity atrophy. The tissue amount available for the intake of a volume unit (weight-volume index) is nearly identical for operated and intact animals in the duodenum and the jejunum. The index functionally increasing for intact animals from the jejunum to the ileum (stenosis due to temporary digesta congestion in the ileum) remained the same with anastomosis animals for 29 or 26 weeks resp. after the operation. As a result of the biochemical and morphological studies it was shown that animals with an ileo-rectal anastomosis are suitable for the determination of nutrient digestibility at the end of the ileum.     

Ileal amino acid digestibility assay for the growing meat chicken--comparison of ileal and excreta amino acid digestibility in the chicken

1. The apparent and true amino acid digestibilities in sorghum, wheat, soyabean meal, meat-and-bone meal, fish meal and blood meal for growing meat chickens were determined using an assay based on the collection of digesta from the terminal ileum and comparison was made with digestibility values determined using an excreta-based assay. 2. Five-week-old meat chickens were given maize-soyabean meal basal diet or mixtures of the basal diet and test diets containing the 6 ingredients as the sole source of dietary protein (50:50 on weight basis). Apparent amino acid digestibility values of assay diets at ileal and excreta levels were calculated using chromic oxide as the indigestible marker. True digestibility values were calculated using endogenous outputs determined by feeding a protein-free diet. Amino acid digestibilities of the ingredients were calculated by difference. 3. The site of measurement had no influence on endogenous amino acid output, the exceptions being aspartic acid and glutamic acid. The output of these two amino acids was higher in the excreta. 4. Significant differences were found between ileal and excreta-based digestibility of certain amino acids in some ingredients, with excreta values being usually higher than the ileal values, indicating a net catabolism of amino acids in the large intestine. The degree of net amino acid disappearance was found to be variable among amino acids and ingredients. In general, threonine had the lowest digestibility at the ileal level and, compared with other amino acids, the highest degredation during passage through the hindgut. 5. The results showed that digestibility determination based on excreta collection will overestimate the uptake for some amino acids in some feeds. The degree of overestimation was often considerable, ranging from 8.9% (apparent digestibility of threonine in soyabean meal) to 56% (apparent digestibility of aspartic acid in wheat). It is concluded that digestibility values measured at the terminal ileum provide a more reliable measure of amino acid availability than those measured in the excreta.     

Effect of soybean meal particle size on amino acid and energy digestibility in grower-finisher swine

A study was conducted using the ileal digestibility technique with grower-finisher pigs to evaluate the effects of particle size reduction of soybean meal (SBM) on amino acid and energy digestibility. Soybean meal was processed through a hammer mill to achieve average particle sizes of 900, 600, 300, and 150 microm. The treatments included the use of two soybean meal sources and soy protein concentrate. One source of SBM was ground to four different particle sizes (i.e., 949, 600, 389, 185); a second source was a common SBM source used in other trials (i.e., 800 microm). The soy protein concentrate had an average particle size of 385 microm. A low-protein (5% casein) diet was fed to determine endogenous amino acid losses. This experiment was conducted in a 7 x 7 Latin Square design in two replicates using 14 crossbred barrows ([Landrace x Yorkshire] x Duroc) that averaged 28 kg BW and 60 d of age. Animals were surgically fitted with a T-cannula at the distal ileum. Treatment diets were fed in meal form, initially at 0.09 kg BW(0.75) and at graded increases at each subsequent period. Pigs within replicate were fed a constant quantity of their treatment diet for a 5-d adjustment period followed by a 2-d collection of ileal digesta samples. Apparent and true digestibility of amino acids was calculated by use of chromic oxide (0.5%) as an indigestible marker. Apparent digestibility of isoleucine, methionine, phenylalanine, and valine increased linearly (P < 0.05) as particle size decreased. True digestibility of isoleucine, methionine, phenylalanine, and valine increased linearly (P < 0.05) as particle size decreased. When the essential amino acids were averaged, apparent digestibility increased (P < 0.10) from 83.5% to 84.9% as particle size decreased, whereas, nonessential amino acid digestibility increased only slightly (P > 0.15). Essential amino acid true digestibility increased numerically from 91.0% to 92.4% as particle size decreased. Energy digestibility was not affected by particle size (P > 0.15). These results suggest that a reduction in particle size of soybean meal resulted in a small increase in the digestibility of its amino acids with the essential amino acids being affected more than the nonessential amino acids. The largest improvement in digestibility, however, was obtained when the particle size was reduced to 600 microm.     

Nitrogen and amino acid absorption in swine. 3. Endogenous secretion and absorption of nitrogen

The endogenous nitrogen in the duodenum and the distal segment of the small intestine of 3 fistulated pigs fed a 15-N-labelled feed protein was determined using the isotope dilution technique. Over 24 hours, the endogenous N secretion was found at least 12.5 g at the end of the duodenum. For the upper segment of the small intestine, a statistically secured correlation between endogenous nitrogen and chyme amount was found to exist. It was possible to determine the true and apparent absorption of the nitrogen for both individual segments of and the whole digestive tract.     

合作猪肌肉氨基酸含量测定及营养价值评价

采用氨基酸自动分析仪测定不同月龄合作猪及对照组八眉猪肌肉氨基酸含量,并通过考察蒸煮处理对氨基酸含量水平的影响,评价合作猪肌肉营养价值。结果表明,合作猪肌肉氨基酸含量高于FAO/WHO的模式标准,可以判断合作猪肉是优质蛋白质来源。蒸煮后,合作猪肌肉中总氨基酸、必需氨基酸、非必需氨基酸以及鲜味氨基酸含量均有所下降,但EAA/TAA、EAA/NEAA上升。多数氨基酸含量在蒸煮后下降,降幅7.61%~78.39%,但丙氨酸、缬氨酸、组氨酸含量有所增加。     

Nitrogen and amino acid absorption in the small intestine of growing pigs. 2. Apparent and true crude protein digestibility and amino acid absorption to the end of the small intestine

Studies of the apparent and true ileal digestibility of crude protein and the apparent and true amino acid (AA) absorption were carried out with 7 female pigs in the live weight range between 22 and 34 kg after ileorectostomy. Protein sources of varied quality with regard to the method of treatment (toasted) and untoasted soybean oilmeal) and to the AA composition (vital gluten or vital gluten + L-lysine X HCl) were used. Distinct differences regarding the apparent ileal digestibility of crude protein and the apparent absorption of amino acids were discovered between the protein sources, the cause of which is to be seen in the different amounts of endogenous N. The true ileal digestibility of crude protein and amino acid absorption were partly distinctly higher than the values of the apparent ileal digestibility of crude protein and AA absorption. On the whole one can say that the results of the investigation gained by means of ileorectostomy can be compared to the values gained from cannulated animals. Thus the experimental method used is suitable for studying the absorption process to the end of the small intestine of pigs.     

Comparison of amino acid digestibility using the ileal digesta from growing chickens and cannulated adult cockerels

Meat-and-bone meal (MBM), which had been heated (150 degrees C) for 0, 1.5, 3 or 5 h, was used along with an indigestible marker in four diets which were fed to young growing chickens and adult cockerels fitted with ileal cannulae. The ileal digesta from each group of birds were sampled and the apparent amino acid digestibilities of the four diets containing MBM were determined. The apparent digestibility values from growing chickens were higher (P less than 0.05) than those from cannulated cockerels. Differences in apparent digestibility of amino acids between diets as a result of heat treatment were consistent for all amino acids when comparing both techniques, with the exception of glutamic acid and arginine.