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1.
Experiments were conducted to determine the effect of the physiological condition of swine on standardized ileal digestibility coefficients (SID). The apparent ileal digestibility coefficients were determined for crude protein and amino acids in six feed ingredients (corn, barley, wheat, soybean meal, canola meal, and meat and bone meal) in growing pigs and in gestating and lactating sows. Growing pigs and lactating sows were given free access to their diets, whereas gestating sows were allowed to consume only 2 kg of feed daily. The nonspecific (basal) endogenous losses of protein and amino acids were determined under similar feeding regimens after feeding a protein-free diet. The SID for crude protein and amino acids were calculated by correcting the apparent ileal digestibility coefficients for the nonspecific endogenous losses of protein and amino acids. With a few exceptions, there were no differences (P > 0.05) in the SID for crude protein and amino acids between growing pigs and lactating sows. Overall, gestating sows had higher (P < 0.05) SID for crude protein and all amino acids, except for tryptophan and aspartate, compared with growing pigs. Likewise, the SID of most amino acids obtained by gestating sows were higher (P < 0.05) than those obtained by lactating sows. Interactions (P < 0.05) between animals and diets were observed for gestating sows compared with growing pigs as well as gestating sows compared with lactating sows. As a consequence, it is not possible to extrapolate data from one feed ingredient to another. On most occasions, the lowest SID among the indispensable amino acids was calculated for threonine, valine, and lysine. It is concluded that gestating sows fed 2 kg of feed per day have higher standardized digestibility coefficients than do growing pigs and lactating sows given free access to their diets. This difference may be due to differences in daily feed intake rather than to the physiological status of the animals. 相似文献
2.
An experiment was conducted to investigate the effects of BW, feed intake, and the physiological condition of the animal on the loss and amino acid composition of endogenous protein in swine. Ten growing barrows and five multiparous sows were equipped with a T-cannula in the distal ileum for digesta collection. A protein-free diet was fed to all animals. The barrows were given free access to the experimental diet. The sows also were allowed to consume the diet on an ad libitum basis, and digesta were collected during lactation and in the following gestation period. In addition, digesta from the gravid sows were collected after restricting the sows to 2 kg of feed per day. For each animal group, the endogenous losses of protein and amino acids were calculated in relation to DMI, and the amino acid composition of endogenous protein was calculated. The total endogenous gut protein loss at the distal ileum of growing pigs, lactating sows, and gestating sows, given free access to feed, was 12.4, 9.4, and 11.2 g/kg DMI, respectively. These values were not different (P > .10). However, when gestating sows were fed only 2 kg/d, 17.8 g of endogenous protein was lost per kilogram of DMI, which was higher (P < .05) than for any of the other groups. This difference was mainly caused by higher (P < .05) losses of glycine, proline, and serine. There were no differences (P > .05) in amino acid composition of endogenous protein between growing pigs, lactating sows, and gestating sows given free access to feed, but restricted-fed gestating sows had an amino acid composition of endogenous protein that was significantly different from that of the other groups. The results from the experiment showed that age, BW, and the physiological condition of the animal have little or no effect on the amount of endogenous protein and amino acids lost at the distal ileum of hogs if calculated in relation to DMI. Likewise, the amino acid composition was not affected by the BW or physiological condition of the animal. However, DMI had a significant effect on endogenous protein losses in sows as well as on amino acid composition of endogenous protein. 相似文献
3.
Effect of fumaric acid and dietary buffering capacity on ileal and fecal amino acid digestibilities in early-weaned pigs 总被引：2，自引：0，他引：2
Experiments were conducted to determine the effect of fumaric acid supplementation and buffering capacity of the diet on ileal and fecal digestibilities of CP, GE, and amino acids in early-weaned pigs. In two experiments, 12 pigs each were weaned at 14 d of age and fitted with a simple T-cannula at the distal ileum between 15 and 17 d of age. In both experiments, the pigs were fed four diets, based on wheat and soybean meal without (control) or with 1, 2, or 3% fumaric acid according to a balanced two-period change-over design. In Exp. 2, the buffering capacity of the diets was increased by supplementation of 3% sodium bicarbonate. The pigs were fed three times daily: equal amounts at 8-h intervals. The diets were supplied at a rate of 5% (wt/wt) of body weight. The inclusion of fumaric acid to the diet with a low buffering capacity increased (P < .05) the ileal digestibilities of CP, GE, and the majority of amino acids. The highest responses were found at an inclusion level of 2% fumaric acid. The improvements in apparent ileal amino acid digestibilities ranged from 4.9 to 12.8 percentage units. Supplementation of fumaric acid to a diet with a high buffering capacity led only to numerical increases in ileal digestibilities of CP, GE, and amino acids. In both studies, fumaric acid supplementation had no effect (P > .05) on the fecal digestibilities of CP, GE, and amino acids, except histidine. A high buffering capacity of the diet decreased the ileal amino acid digestibilities by 1 to 10 percentage units compared with diets with the low buffering capacities. In both experiments, ileal and fecal digestibilities were higher (P < .05) in Period 2 (on d 24 after weaning) than in Period 1 (on d 11 after weaning). A positive correlation (P < .05) between ileal digestibilities and fumaric acid supplementation to the diets with the low buffering capacities was observed in Period 1 (on d 11 after weaning), but not in Period 2 (on d 24 after weaning). No relationship (P > .05) between ileal digestibilities and fumaric acid supplementation to the diets with a high buffering capacity could be established. In conclusion, supplementation of fumaric acid to starter diets during the first 3 to 4 wk after weaning increases the ileal digestibilities of GE, CP, and amino acids. 相似文献
4.
The effect of source of fiber on ileal and fecal amino acid digestibility and bacterial nitrogen excretion in growing pigs. 总被引：4，自引：0，他引：4
Studies were carried out with six barrows (initial BW 50 kg) to determine the effect of two fiber sources on the apparent ileal and fecal N and amino acid digestibilities and bacterial N excretion in feces. The pigs, fitted with a simple T-cannula at the distal ileum, were fed three cornstarch-based diets formulated to contain 16% CP from soybean meal according to a repeated 3 x 3 Latin square design. Diet 1 did not contain additional fiber. Diets 2 and 3 contained 10% powdered cellulose and 10% barley straw (ground through a 2-mm mesh screen), included at the expense of cornstarch, respectively. The pigs were fed 900 g at each meal twice daily, 0800 and 2000. Feces were collected for 48 h after a 10-d adaptation period. Thereafter, ileal digesta were collected for 24 h. Chromic oxide was used as a digestibility marker. With the exception of leucine, the inclusion of fiber did not affect (P greater than .05) the ileal digestibilities of the indispensable amino acids. The values for the average of the ileal digestibilities of the indispensable amino acids were 85.3, 82.9, and 83.2% for diets 1, 2, and 3, respectively. On the other hand, the inclusion of fiber decreased (P less than .05) the fecal digestibilities of all the indispensable amino acids. The values for the average of the fecal digestibilities of the indispensable amino acids were 91.7, 87.4, and 89.1% for diets 1, 2, and 3, respectively. These decreases resulted from an increase (P less than .05) in the excretion of bacterial N, which was measured using 2,6-diaminopimelic acid as a marker. In conclusion, as measured with the ileal analysis method, the inclusion of fiber had little effect on the digestible amino acid supply. 相似文献
5.
Apparent digestibility of nitrogen and amino acids in protein feedstuffs by growing pigs 总被引：3，自引：0，他引：3
D A Knabe D C LaRue E J Gregg G M Martinez T D Tanksley 《Journal of animal science》1989,67(2):441-458
Eight digestion trials were conducted with pigs fitted with ileal T-cannulas to determine the apparent digestibilities of N and amino acids in common protein feedstuffs. Trial-to-trial variation was minimal as determined by the variation in digestibilities for soybean meal, which was evaluated in each trial. Apparent digestibilities varied widely; ileal N digestibility ranged from 88 to 63%, and ileal lysine digestibility ranged from 93 to 40%. In general, ring-dried blood meal, corn gluten meal, Menhaden fish meal, poultry-by-product meal and extruded whole soybeans were the most digestible, followed by canola meal, sunflower meal, peanut meal and meat and bone meal. Cottonseed meal and feather meal were the least digestible. Mean values for each feedstuff agree well with published data. Variation in digestibilities among samples of the same feedstuff was greater for the meat and bone meals. Regression of ileal essential amino acid digestibilities on ileal and fecal N digestibility indicated that amino acid digestibilities can be predicted more precisely from ileal N digestibility than from fecal N digestibility. However, neither ileal nor fecal N digestibility could be used with a high degree of certainty to predict ileal amino acid digestibilities. 相似文献
6.
Growth trials with starter (n = 120, 6.8 kg initially, 28 d of age, Exp. 1) and finisher (n = 70, 59 kg initially, Exp. 2) pigs were conducted to compare quality protein maize (QPM, .40% lysine) and normal corn (.31% lysine) in simple corn-based diets containing the same levels of soybean meal. In Exp. 1, pig performance was similar (P greater than .10) on all diets, regardless of the level of soybean meal, suggesting that QPM and normal corn have similar feeding value in lysine-adequate (.99 to 1.11%) diets. In Exp. 2, less soybean meal was needed in QPM than in normal corn diets to maximize performance; increasing soybean meal from 10.8 to 13.8% improved rate (P less than .05) and efficiency (P less than .01) of gain of pigs fed normal corn diets but had no effect on performance of pigs fed QPM diets. A QPM-based diet containing 6% soybean meal and supplemental lysine and tryptophan failed to maximize feed efficiency, but growth rate was equal to that obtained on the normal corn diet with 13.8% soybean meal. The apparent fecal digestibility of GE and ileal digestibility of N were similar for QPM and normal corn, but apparent ileal digestibility of most essential amino acids was slightly higher for QPM (Exp. 3). Experiment 4 compared apparent digestibilities of QPM, conventional opaque-2 corn and two high-protein corns. Digestibilities differed (P less than .05) among the corns, but the absolute differences were small and were likely due to differences in amino acid content of the corns.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
7.
Eight male Holstein calves (body weight 68 +/- 5 kg; age 75 +/- 6 d), each with a permanent re-entrant pancreatic cannula and T-type ileal and duodenal cannulas, were used in a crossover design with four animals per group to determine amino acid kinetics and digestibilities in the digestive tract of calves fed soybean meal (SBM) and canola meal (CM) protein. The SBM and CM diets were fed twice daily at a level of 900 g at each feeding time (air-dry basis). With the exception of methionine, crude protein and amino acid flows at the proximal duodenum, expressed as a percentage of intake, were not influenced by dietary protein source. Apparent ileal and total tract digestibilities of CP and amino acids were reduced (P less than .05) by feeding CM compared to SBM, but apparent ileal digestibility of methionine was not affected by dietary protein source. Except for methionine, net disappearance of all amino acids in the small intestine, relative to the amount fed, was higher for the SBM diet than for the CM diet. Net disappearance or synthesis of amino acids in the large intestine were not affected by dietary protein source. Similarly, dietary protein source did not affect (P greater than .05) the secretion of pancreatic juice or concentrations of protein, chymotrypsin and trypsin in pancreatic juice. Soybean meal protein has higher ileal and total gastrointestinal tract digestibility than CM protein for young, growing calves. 相似文献
8.
The apparent ileal digestibilities of amino acids and rate of passage were evaluated in pigs (BW = 78.3 +/- 7.4 kg) fed a semipurified diet. The pigs were fed 1.82, 2.73, or 3.65 kg DMI/d. The highest level of feed intake was considered to be ad libitum feeding. The pigs were fed according to a 3 x 3 Latin square design and were allowed to adapt to each experimental diet for 5 d. This was followed by 1 d of continuous collection of ileal digesta and a 2nd d of continuous collection separated into six 2-h postprandial time blocks. Ytterbium chloride hexahydrate was used to determine rate of passage. The ileal digestibilities of amino acids and rate of passage were unaffected (P > 0.05) by level of feed intake. The use of correction factors to more accurately express amino acid concentrations in the diet and digesta affected (P < 0.05) the apparent ileal digestibility coefficients of some amino acids. 相似文献
9.
1. The apparent ileal and excreta digestibilities of amino acids in 15 samples representing 12 food ingredients were determined using 5-week-old male broiler chickens. The ingredients included 3 samples of cereals (wheat, maize and sorghum), 6 samples of plant protein meals (soyabean meal, cottonseed meal, canola meal and sunflower meal) and 6 samples of animal protein meals (meat meal, meat-and-bone meal, feather meal and fish meal). 2. The test ingredients were incorporated as the sole source of dietary protein in assay diets. Each diet was offered ad libitum to 3 pens (4 birds/pen) from d 35 to d 42 post-hatching. Total collection of excreta was carried out during the last 4 d. All birds were killed on d 42 and the contents of the lower half of the ileum were collected. Apparent ileal and excreta amino acid digestibilities were calculated using acid-insoluble ash as the indigestible marker. 3. The influence of site of measurement was found to vary among food ingredients, among samples within an ingredient and among different amino acids within an ingredient. Ileal amino acid digestibility values were similar in some ingredients, but significantly lower or higher in others than the corresponding excreta values. 4. Average ileal and excreta amino acid digestibilities in sorghum and maize were similar, but significant differences were observed for individual amino acids. In contrast, ileal amino acid digestibility values were higher than the corresponding excreta digestibility values in wheat. 5. The average ileal and excreta digestibilites of amino acids in the 3 soyabean meal samples were similar although small, but significant differences were noted for individual amino acids. Site of measurement had no effect on the digestibility of amino acids in canola meal. Digestibilities of valine, isoleucine, phenylalanine, histidine, glutamic acid, alanine and tyrosine in sunflower meal and those of valine, methionine, isoleucine, leucine, lysine, glutamic acid and alanine in cottonseed meal were lower by excreta analysis. 6. Digestibilities in animal protein meals, with the exception of blood meal and fish meal, were consistently higher by excreta analysis. Ileal-excreta differences in individual amino acid digestibilities were more evident in feather meal, meat meal and meat-and-bone meal. 7. Threonine and valine were the indispensable amino acids that were more frequently influenced by the site of measurement. Of the dispensable amino acids, aspartic acid, serine, glutamic acid and alanine were the most affected. 8. Differences determined between ileal and excreta digestibilities in the present study clearly demonstrate that amino acid metabolism by hindgut microflora in chickens may be substantial and that digestibilities measured in the terminal ileum are more accurate measures of amino acid availability than those measured in the excreta. 相似文献
10.
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. 相似文献
11.
Forty crossbred barrows (initial average BW of 20 kg) were fitted with T-cannulas in the distal ileum to determine the effects of extrusion of soybean meal on the apparent ileal and fecal digestibilities of lysine, N, and GE. A basal corn-soybean meal diet was formulated to contain .525% lysine. Nonextruded soybean meal (SM), extruded soybean meal (ESM), and L-lysine.HCl (LLH) replaced cornstarch in the basal diet to make diets containing .60, .675, and .75% total dietary lysine for each lysine source. Treatments were arranged as a 3 x 3 factorial with the basal diet as an additional treatment. Ileal and fecal digestibilities of lysine were not affected (P greater than .05) by source of lysine. However, linear increases (P less than .05) occurred in ileal lysine digestibilities with increasing concentrations of dietary lysine provided as LLH, but not when lysine was provided as SM or ESM. Apparent ileal and fecal retention of N as percentages of N absorbed or consumed were greater (P less than .05) for diets containing LLH than for diets containing SM, and diets containing ESM were intermediate. Linear increases (P less than .05) occurred in ileal and fecal N retained as percentages of N absorbed or consumed with increasing concentration of dietary lysine provided as LLH or ESM, but not when provided as SM. Fecal DE and ME (kilocalories per gram of diet) for diets containing LLH and ESM were similar and greater (P less than .05) than the values obtained for diets containing SM.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
12.
Effects of protein and carbohydrate sources on digestibility and digesta flow rate in weaned pigs fed a high-fat, dry diet 总被引：1，自引：0，他引：1
Two trials were conducted to evaluate the effects of protein source (48% CP soybean meal or casein) and carbohydrate source (25% dextrose or 25% lactose) on digestibility and digesta flow rate in early-weaned pigs. Diets contained 10% crude soybean oil and were formulated to contain 3.5 g lysine, 2.3 g Ca and 2.0 g P per 1,000 kcal DE of diet. In Trial 1, nutrient digestibility was greater for older than for younger pigs. Apparent digestibilities for energy, DM, CP and fat were lower (P less than .08) for younger and older pigs fed soybean meal rather than casein. Digestibility of soluble carbohydrates was less (P less than .02) for younger pigs fed soybean meal rather than casein as a protein source. Fat digestibility was lower (P less than .05) in younger pigs fed dextrose than in pigs fed lactose. A protein X carbohydrate source interaction (P less than .01) existed for fat digestibility by older pigs. In Trial 2, pigs were euthanatized, and digestibilities anterior to the ileum and the colon (pre-ileal and pre-cecal) were determined. At the ileum, fat digestibility was lower (P less than .05) for pigs fed soybean meal, whereas CP digestibility was lower (P less than .05) for pigs fed either soybean meal or dextrose. A protein X carbohydrate interaction was observed for ileal digestibilities of DM (P less than .06) and total carbohydrates (P less than .03) with lowest values obtained for the soybean meal plus dextrose diet. For casein diets, digestibility values were similar between the two carbohydrate sources.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
13.
The apparent digestibility of nitrogen and amino acids was measured by the ileal and faecal methods in pigs fed nine barleys differing in nitrogen content (from 1.73 to 2.16 per cent/DM). A positive (r = 0.87) and significant relationship was found between the apparent nitrogen digestibility at the end of the ileum and the crude protein content of barley. Generally, the higher the protein of the grain, the higher the ileal digestibilities of the amino acids. For most amino acids the faecal values were greater than the ileal ones. This being specially so for threonine, tryptophan, histidine and cystine belonging to the nutritionally important amino acid group. When the relationship between the amino acid and nitrogen digestibilities at the level of ileum is considered, the values were found to be similar to that of nitrogen in the case of tryptophan, higher for isoleucine, valine (both 2-3 units), cystine, histidine, leucine, methionine (all 5-6 units) and phenylalanine (10 units) and lower only for lysine and threonine (7-8 dig. units). 相似文献
14.
妊娠母猪中黑麦草粉常规养分的消化率研究 总被引：2，自引：0，他引：2
黑麦草在盛花期刈割,自然风干,营养物质含量为：总能１６．３６ＭＪ／ｋｇ,干物质８９．４３％,粗蛋白质１０．４７％,粗纤维３７．２１％,钙０．３３％,总磷０．２２％,平均必需氨基酸为０．２７％,其中赖氨酸、蛋氨酸、苏氨酸和色氨酸含量分别为０．３４％、０．１９％、０．３５％和０．０５％。试验选用４头妊娠母猪。以玉米－豆粕型日粮为基础日粮,分别用黑麦草粉替代１０％、２０％和３０％的基础日粮作为试验日粮。采用４×４拉丁方设计。结果表明０％、１０％、２０％和３０％黑麦草粉组饲料总能的消化率分别为７９．３８％、７４．６９％、６５．１８％和５９．８８％;粗蛋白质消化率分别为７８．９３％、７６．３７％、７２．４３％和６９．１６％;干物质的消化率分别为７７．３０％、７４．５１％、６６．１６０％和６１．６０％。经回归分析得出黑麦草粉总能、粗蛋白质、干物质的消化率依次为１１．５４％、４７．６５％、２２．３０％。黑麦草粉的总氨基酸、总必需氨基酸和总非必需氨基酸的平均粪表观消化率分别为３７．９８％、３７．７８％和３８．２３％;赖氨酸、蛋氨酸、苏氨酸、色氨酸的粪表观消化率为１８．４９％、２５．０８％、１３．９５％、５６．３４％。 相似文献
15.
Real ileal protein and amino acid digestibilities in feedstuffs for growing pigs as determined with the 15N-isotope dilution technique 总被引：3，自引：0，他引：3
Twelve gilts, with an average initial BW of 38 kg, were fitted with a simple T-cannula at the distal ileum and two catheters in the external jugular veins. The animals were fed 700 g of one of the experimental diets, twice daily at 0800 and 2000. Diets 1 and 2 were cornstarch-based diets formulated to contain 16% CP from soybean meal and canola meal, respectively. Diets 3 and 4 contained 93.9% wheat and barley, respectively. Chromic oxide was included to determine nutrient digestibilities. Following recovery from surgery, 15N-leucine was infused continuously via a jugular catheter for 9 d at a rate of 40 mg.kg BW-1.d-1. Blood samples were taken at every feeding. Ileal digesta were collected for 24 h on d 7 and 9 of the infusion period. Assuming that the 15N-enrichment excess in the trichloroacetic acid-soluble fraction of the blood was similar to that in endogenous N, the contribution of endogenous to total N in ileal digesta was calculated. The amount of endogenous protein (N x 6.25) recovered in digesta collected from the distal ileum were 25.5, 30.5, 27.4 and 27.7 g/kg DM intake for the pigs fed diets 1, 2, 3 and 4, respectively. In the same order for the diets, the real ileal protein digestibilities were 97.5, 84.1, 99.0 and 94.2%, respectively. In addition, the real ileal amino acid digestibilities were calculated. The recoveries of endogenous protein in ileal digesta and the real ileal protein and amino acid digestibilities were higher than those determined by feeding protein-free diets for determining the recovery of endogenous protein and amino acids in ileal digesta. 相似文献
16.
Thirty primiparous sows were individually penned in a thermoneutral (20 degrees C) or hyperthermal (32 degrees C) environment and fed a high-starch (corn-soybean meal basal), high-fiber (48.5% wheat bran) or high-fat (10.6% choice white grease) diet from d 100 of gestation through a 22-d lactation to determine the effects of thermal environment and dietary energy source on energy and N digestibility in lactating sows. Voluntary feed intake and total feces and urine output were determined from d 12 through d 14 postpartum. Heat exposure (32 degrees C) depressed (P less than .05) voluntary feed, ME and N intake and lowered (P less than .05) apparent daily N retention. Heat exposure did not alter (P greater than .15) digestibility, expressed as percentage of intake, of dietary energy or N. Dietary additions of wheat bran depressed (P less than .05) the proportion of gross energy retained as ME by 12 and 14 percentage units and the apparent digestibility of N by 2.5 and 4.5 percentage units at 20 and 32 degrees C, respectively, compared with those of the basal diet. Dietary additions of choice white grease did not alter (P greater than .15) energy digestibility but increased (P less than .05) the proportion of N digested and retained in both environments. Apparent ME of the wheat bran, corn-soybean meal mix and choice white grease (determined by difference) was 2.72, 3.70 and 8.43 Mcal/kg DM and was independent of thermal environment. Digestibility of fibrous and starchy feedstuffs was similar in lactating sows and growing pigs allowed to consume feed ad libitum, whereas fat was more digestible in the sows. 相似文献
17.
18.
This study was designed to quantify the effect of soyhulls on N and AA digestibilities of soybean meal for growing pigs. Soyhulls were incorporated into 17% CP diets containing 33.25% soybean meal (SBM) at 0, 3, 6, or 9% (as-fed basis) and fed to 35-kg barrows to determine their effect on apparent and true digestibility of DM, GE, N, and AA measured at the terminal ileum. Positive and negative control diets containing 1.05% lysine were formulated with 35% SBM and 27% soy protein concentrate (SPC), respectively. A low-protein, casein-based diet was used to estimate endogenous AA losses. Soyhulls were incorporated into experimental diets at the expense of cornstarch, and SBM levels were adjusted to accommodate the contribution of CP from soyhulls. Fourteen pigs were surgically fitted with simple T-cannula at the distal ileum and fed the seven semipurified cornstarch diets based on a replicated 7 x 7 Latin square design. Each period lasted 7 d, with diet acclimation from d 1 to 5 and ileal sample collection for 12 h on d 6 and 7. Feed was offered at a level of 90 g/kg BW(0.75) in two equal portions at 0800 and 2000. Apparent ileal digestibilities of DM and GE decreased approximately six percentage units with the addition of soyhulls (linear, P < 0.05), whereas N was not affected. Both apparent and true ileal digestibilities of arginine, histidine, lysine, phenylalanine, aspartic acid, serine, and tyrosine also exhibited a decrease (linear, P < 0.05) of up to five percentage units with the addition of soyhulls. True ileal lysine digestibility of SBM decreased from 90.3 to 87.7% with the addition of 9% soyhulls. The endogenous nutrient fraction measured at the distal ileum was rich in proline, glutamic acid, and glycine, with losses greater than 1,000 mg/kg of DMI for each AA, and contained minimal amounts of tryptophan, methionine, and cystine. The current data suggest that a 0.2% decrease in some true ileal indispensable AA digestibilities may result with each 1% increase in soyhull inclusion in semipurified diets containing SBM as the sole source of AA as fed to growing pigs. 相似文献
19.
Comparison of amino acid digestibility using the ileal digesta from growing chickens and cannulated adult cockerels 总被引：1，自引：0，他引：1
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. 相似文献
20.
Evaluation of the homoarginine technique for measuring true ileal amino acid digestibilities in pigs fed a barley-canola meal-based diet 总被引：2，自引：0，他引：2
Nyachoti CM McNeilage-Van de Wiele EM de Lange CF Gabert VM 《Journal of animal science》2002,80(2):440-448
The homoarginine technique has been suggested as a means to determine true ileal amino acid digestibilities in nonruminant animals fed protein-containing diets. Conditions for guanidinating lysine to homoarginine in barley and canola meal and the effect of this process on nutrient composition and ileal digestibilities in the resulting material were investigated. Conditions tested were methylisourea concentration (0.4, 0.5, or 0.6 M) and reaction time (4 or 6 d) at pH 10.5. Using 0.4 methylisourea M solution for 4 or 6 d gave guanidination rates of 72.5 and 78.5% for barley and 72.3 and 75.2% for canola meal, respectively. Using 0.5 M gave 88.0 and 84.6% guanidination rates in barley and canola meal, respectively, after a 6-d reaction time. Under these conditions, guanidination did not change the nutrient composition of barley (P > 0.10), whereas it increased CP (38.4 vs 49.0%), crude fiber (10.2 vs 16.0%), acid detergent fiber (30.0 vs 43.4%) and neutral detergent fiber (29.8 vs 49.4%) levels in canola meal (P < 0.05). Four 33.6-kg barrows fitted with a simple T-cannula at the terminal ileum were fed a 16% CP unguanidinated barley and canola meal-based diet for four consecutive 14-d periods. Ileal digesta were collected continuously for 24 h on d 12 and 14 to determine apparent nutrient digestibilities. On the morning of d 14, pigs were fed a diet in which half of the barley and canola meal was replaced with guanidinated material for determining true ileal amino acid digestibilities. Digesta samples were pooled by pig and by 24-h period to give 16 observations per diet. Apparent ileal digestibilities of DM, CP, and AA in the unguanidinated and guanidinated barley-canola meal diet were similar (P > 0.10) despite the changes observed in canola meal. Apparent ileal lysine digestibility was 73.9 and 74.5% in the unguanidinated and guanidinated diet, respectively. The true ileal lysine digestibility was 88.1%. The present results show that guanidination does not interfere with digestion and further support the use of the homoarginine method for determining true ileal amino acid digestibilities in pigs fed practical diets. A methylisourea solution of 0.5 M and a 6-d reaction time are recommended for converting lysine to homoarginine in barley and canola meal. 相似文献