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1.
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   

2.
The digestibility of AA in dry extruded-expelled soybean meal (DESBM) and regular, solvent-extracted soybean meal (SBM) were determined in pigs and poultry. In the pig assay, 4 Cotswold barrows (average initial BW of 80.4 kg) fitted with a T-cannula at the distal ileum were allotted to 4 semipurified diets in a 4 x 4 Latin square design. Diet 1, a low protein diet (5% casein), was used to quantify endogenous CP and AA losses. Diets 2, 3, and 4 were formulated to contain 35% regular, solvent-extracted SBM; batch 1 of DESBM (DESBM-1); and batch 2 of DESBM (DESBM-2), respectively, as the sole source of protein. The DESBM samples were obtained from 2 different batches but were subjected to the same processing conditions. Chromic oxide (0.3%) was included as a digestibility marker in all diets. Compared with DESBM-1 and DESBM-2, apparent ileal digestibility of DM in SBM was greater (P < 0.05). Apparent and true ileal digestibilities of AA in SBM were greater (P < 0.05) compared with DESBM-2. In the poultry assay, 4 dietary treatments were each assigned to adult cecectomized roosters in a completely randomized design. Treatment 1 was a nonnitrogenous diet (NND; 90% sucrose and 10% vegetable oil) used to estimate endogenous N and AA losses. Treatments 2, 3, and 4 contained SBM, DESBM-1, and DESBM-2 as the only source of protein. Each of these diets was fed in 25-g quantities formulated to provide 5 g of CP from the respective soybean meal source. The SBM had greater (P < or = 0.05) true digestibility for isoleucine, leucine, cysteine, proline, serine, and tyrosine compared with DESBM-1. The results indicate that, relative to regular, solvent-extracted soybean meal, AA digestibilities of different batches of dry extruded-expelled soybean meal varied in pigs and poultry.  相似文献   

3.
This experiment was designed to evaluate the effects of selected soybean (SB) processing byproducts (gums, oil, soapstock, weeds/trash) when added back to soybean meal (SBM) during processing on the resulting nutrient composition, protein quality, nutrient digestibility by swine, and true metabolizable energy (TMEn) content and standardized AA digestibility by poultry. To measure ileal DM and nutrient digestibility, pigs were surgically fitted with a T-cannula in the distal ileum. The concentration of TMEn and the standardized AA digestibility by poultry were determined using the precision fed cecectomized rooster assay. Treatments in the swine experiment included SBM with no by-products; SBM with 1% gum; SBM with 3% gum; SBM with 0.5% soapstock; SBM with 1.5% soapstock; SBM with 2% weeds/trash; SBM with a combination of 3% gum, 1.5% soapstock, and 2% weeds/trash; SBM with 5.4% soybean oil; and roasted SB. A 10 x 10 Latin square design was utilized. The experiment was conducted at the University of Illinois, Urbana-Champaign, and at The Ohio State University, Columbus. In the swine experiment, apparent ileal DM, OM, CP, and AA digestibilities were reduced (P < 0.05) when pigs consumed the combination by-product diet compared with the diet containing no by-products. Apparent ileal digestibilities of DM, CP, and total essential, total nonessential, and total AA were lower (P < 0.05) for any diet containing by-products compared with the diet with no by-products. Apparent ileal digestibilities of DM, OM, CP, and AA were lower (P < 0.05) for the roasted SB-compared with the SB oil-containing diet. In the rooster experiment, TMEn values were greater (P < 0.05) for roasted SB compared with SBM with no by-products and increased linearly as the addition of soapstock increased. Individual, total essential, total nonessential, and total AA digestibilities were lower (P < 0.05) for roosters fed roasted SB versus SBM devoid of by-products. Gums, soapstock, and weeds/trash reduce the nutritive value of the resultant meal when they are added back during processing.  相似文献   

4.
An experiment was conducted to measure the effect of adding soybean oil to soybean meal (SBM) and soy protein concentrate (SPC) on apparent (AID) and standardized (SID) ileal digestibility of CP and AA by growing pigs. A second objective was to compare AID and SID of AA in a new high-protein variety of full fat soybeans (FFSB) to values obtained in other soybean products. Commercial sources of FFSB (FFSB-CV), SBM, and SPC, and of a new high-protein variety of FFSB (FFSB-HP) were used in the experiment. Four diets were prepared using each soybean product as the sole source of CP and AA in 1 diet. Two additional diets were formulated by adding soybean oil (7.55 and 7.35%, respectively) to the diets containing SBM and SPC. A nitrogen-free diet was also used to measure basal endogenous losses of CP and AA. The 2 sources of FFSB were extruded at 150 degrees C before being used in the experiment. Seven growing barrows (initial BW = 26.2 kg) were prepared with a T-cannula in the distal ileum and allotted to a 7 x 7 Latin square design. Ileal digesta were collected from the pigs on d 6 and 7 of each period. All digesta samples were lyophilized and analyzed for DM, CP, AA, and chromium, and values for AID and SID of CP and AA were calculated. The addition of oil improved (P < 0.05) the SID of most indispensable AA in SBM and SPC. The SID for 6 of the indispensable AA in FFSB-HP were greater (P < 0.05) than in FFSB-CV, and the SID for all indispensable AA except Met was greater (P < 0.05) in FFSB-HP than in SBM. However, the SID for most AA in FFSB-HP was similar to SBM with oil and SPC, but these values were lower (P < 0.05) than in SPC with oil. In conclusion, the addition of oil improved the SID of most AA in SBM and SPC fed to growing pigs, and the SID of AA in FFSB-HP were greater than in SBM and similar to the SID of AA in SBM with oil and in SPC.  相似文献   

5.
This study sought to determine whether fermentation could increase apparent ileal digestibility (AID) of dry matter (DM), nitrogen (N), energy (E) and amino acids (AA) in fermented soybean meal (FSBM) greater than that of soybean meal (SBM) in weaned pigs. Four weaned pigs (10.00 ± 0.30 kg) were surgically equipped with T‐cannulas and randomly followed a 4 × 4 Latin square design of treatments (SBM, FSBM, fish meal and spray‐dried plasma protein). Overall, the fermentation process was able to reduce the amount of anti‐nutritional factors (ANF), including trypsin inhibitors, raffinose and stachyose, in the FSBM diet, which were significantly reduced by 39.4, 92.2, and 92.9%, respectively, as compared to the SBM diet. As a consequence of ANF reduction in FSBM, the AID of DM, N and E as well as AA was significantly greater with FSBM than SBM. Taken all together, the fermentation process improved the nutritional quality of SBM, due to ANF reduction, leading to improvement of digestibility of AA. As such, FSBM can be potentially used as a specialized feed ingredient, especially for young animal diets in an attempt to reduce diet costs.  相似文献   

6.
Ileally cannulated pigs were used to assess the effects of four dietary levels of microbial phytase (Natuphos) on the apparent and true digestibility of Ca, P, CP, and AA in dehulled soybean meal. Fourteen pigs (25 kg initial BW) were surgically fitted with T-cannulas at the terminal ileum and assigned to diets in a replicated 7 x 7 Latin square design. Following a 14-d recovery, four diets consisting of 30.5% soybean meal with 0, 500, 1,000, or 1,500 units of phytase/kg of diet were fed. Diets 5 (1.05% lysine, 0.90% Ca, and 0.75% P) and 6 (1.05% lysine, 0.90% Ca, and 0.75% P) contained 35.25% soybean meal and 27.0% soy protein concentrate, respectively. Diet 7 (0.37% lysine, 0.03% Ca, and 0.05% P) was a low-CP, casein-based diet used to estimate the nonspecific endogenous losses of Ca, P, CP, and AA in order to estimate the true digestibility of these nutrients. All diets contained cornstarch and dextrose and were fortified with vitamins and minerals. Chromic oxide was used as an indigestible indicator. The diets were fed daily at 9% of metabolic BW (BW0.75). Apparent and true ileal digestibility of P increased quadratically (P < 0.01) and true digestibility of Ca increased linearly (P < 0.07) with increasing levels of phytase. Apparent digestibility of Ca was unaffected (P = 0.15) by phytase level. Apparent and true ileal digestibility of CP and most AA increased slightly with the addition of 500 units of phytase/kg of diet, but not at higher levels of phytase supplementation (in most cases, cubic effect, P < 0.05). Apparent and true ileal nutrient digestibility coefficients were unaffected by soybean meal source (Diet 1 vs Diet 5), except for arginine and Ca. The apparent and true digestibility coefficients for most of the AA tended (P < 0.10) to be lower in diets containing soy protein concentrate vs the common source of soybean meal used in Diet 5, but ileal digestibilities of Ca and P were unaffected (P = 0.15). In this study, supplemental microbial phytase did not improve the utilization of AA provided by soybean meal but was an effective means of improving Ca and P utilization by growing swine fed soybean meal-based diets.  相似文献   

7.
Ten 56-d-old, 15-kg barrows were surgically fitted with a postvalvular T-cecum cannula at the ileo-cecal junction to evaluate the effect of microbial phytase on apparent and true ileal AA digestibility and N utilization. A semipurified cornstarch- and soybean meal-based diet was formulated to contain 3.4 Mcal of DE/kg, 17.0% CP, 0.8% Ca, and 0.6% P but had a low phytate-P concentration (0.13%; all on an as-fed basis). Chromic oxide and dysprosium chloride were used as indigestible markers. The basal diet was supplemented with 0 or 1,000 phytase units/kg of microbial phytase. Postprandial plasma urea N and alpha-amino N concentrations, excretion of Ca, P, and N in feces and urine, and ileal AA digestibilities were determined 3 times at 4-wk intervals beginning at 70 d of age. The homoarginine (HA) method was used to determine endogenous AA flow by replacing 50% of the basal protein with guanidinated protein. Microbial phytase had no effect on apparent ileal digestibility (AID) or on true ileal digestibilities of N and most AA but did increase AID for arginine (P = 0.006) and methionine (P = 0.037). However, in HA diets, phytase increased the AID of CP (P = 0.01) and several AA. Addition of microbial phytase had no effect on the postprandial alpha-amino N concentrations in plasma but increased overall plasma urea N concentrations (P = 0.035). Barrows fed phytase-supplemented diets had decreased P in feces (P = 0.003) and greater P in urine (P = 0.001) but comparable total P excretion compared with barrows fed no phytase-supplemented diets. In conclusion, the addition of phytase to a semi-purified soybean meal-based diet did not affect the AID of several AA. In addition, differences between the basal and HA diets in N digestibilities indicated that that guanidination may limit the use of the HA method in determining endogenous protein losses.  相似文献   

8.
An experiment was carried out to determine the ileal digestibility values of NDF, CP, and AA associated with NDF in different samples of wheat shorts consisting of different proportions of wheat bran, shorts, and flour, hereafter referred to as wheat fractions. Six barrows (average initial BW 37.2 kg, and fitted with a simple T-cannula at the distal ileum) were fed one of six experimental diets, formulated to contain 17% CP (as-fed basis), according to a 6 x 6 Latin square design. Diets A, B, C, D, and E contained 17.53% soybean meal (SBM), which contributed 50% CP to these diets. The diets contained shorts, bran, or flour alone or in combination, contributing the remaining 50% CP to these diets. The proportions of shorts, bran, and flour in the wheat fractions were 70% shorts and 30% bran in diet A, 85% shorts and 15% bran in diet B, 100% shorts in diet C, 85% shorts and 15% flour in diet D, and 70% shorts and 30% flour in diet E. Diet F contained 35.05% soybean meal, which provided the sole source of dietary CP. Chromic oxide was used as a digestibility marker. During the first experimental period, the daily dietary allowance was provided at a rate of 5% (wt/wt) of the average BW. Thereafter, the allowance was increased by 100 g at each successive period. Each experimental period comprised 12 d. Following a 7-d adaptation period, feces were collected for 48 h and ileal digesta for a total of 24 h. The contribution of CP and AA associated with NDF gradually decreased from wheat fraction A to E, reflecting a decrease in NDF content from 42.3 to 29.5%. Of the indispensable AA in wheat fraction A, the contributions ranged from 12.9 to 15.9%. In wheat fraction E, these values ranged from 9.0 to 11.3%. The ileal digestibility values of NDF ranged from 11.8% in diet E to 17.1% in diet C (P > 0.05). There were usually no differences (P > 0.05) in the ileal digestibilities of AA associated with NDF between the wheat fractions. However, with the exception of lysine and tyrosine, there were negative correlations (P < 0.05) between the apparent ileal AA digestibilities and the content (%) of CP associated with NDF in the wheat fractions. Furthermore, there was no effect (P > 0.05) of the diets containing wheat fractions on the recovery of bacterial protein and mucin in ileal digesta.  相似文献   

9.
An experiment evaluated the ileal apparent and standardized AA and apparent energy digestibilities in grower-finisher pigs of 5 sources of distillers dried grains with solubles (DDGS) from corn. The 5 DDGS sources were analyzed for AA, GE, NDF, ADF, and color score. Diets were formulated to contain 15% CP from the test DDGS sources (approximately 60% of the diet). A low-protein (5% casein) diet was used to estimate basal endogenous AA losses. The experiment was conducted in 2 replicates of a 6 x 6 Latin Square design, with 6 treatments and six 1-wk periods. The experiment used 12 crossbred barrows [(Yorkshire x Landrace) x Duroc], averaging 28 kg of BW and 60 d of age, and surgically fitted with a T-cannula in the distal ileum. After a 10-d recovery period, treatment diets were fed in meal form, initially at 0.09 kg . BW(0.75). Feed intake was equalized between pigs within each period and increased for each subsequent period. Periods included 5 d of diet acclimation followed by two 12-h ileal digesta collections, one on d 6 and one on d 7. Apparent and standardized digestibility of AA was calculated using chromic oxide (0.4%) as an indigestible marker. The results demonstrated that apparent and standardized lysine digestibilities ranged from 24.6 to 52.3% and 38.2 to 61.5%, respectively. Average apparent essential AA digestibility was lower (P < 0.05) in sources 1 and 5, the 2 sources that were darkest in color. Apparent and standardized digestibility of the averaged nonessential AA were lower (P < 0.05) in source 5 than in all other sources. Source 5, the darkest colored DDGS, had a 10% lower (P < 0.05) average apparent and standardized essential AA digestibility and was more than 15% lower (P < 0.05) in lysine digestibility than the 3 lightest colored sources. Apparent ileal energy digestibility did not differ among the 5 sources. Lysine content and digestibility seemed to be reduced to a greater extent by the darker colored DDGS than the other essential AA, suggesting that the Maillard reaction reduced total lysine content and lowered its digestibility. These results, therefore, imply that darker colored DDGS sources may have lower (P < 0.05) analyzed lysine contents, as well as lower (P < 0.05) lysine and essential AA digestibilities, than lighter colored DDGS sources.  相似文献   

10.
Growing conditions and processing technologies to which soybeans (SB) are exposed have an effect on digestibilities of AA found in the resultant soybean meals (SBM). This study evaluated SBM from five major SB-producing countries (Argentina, Brazil, China, India, and the United States). An industry representative in each country collected samples of unprocessed SB and SBM subjectively determined to be of high, intermediate, or low quality. The SB from each country were processed into SBM under uniform conditions in the United States. Five experiments (each examining the three SBM and the SB processed in the United States from a single country) were conducted to determine true ileal AAd digestibilities. In addition, a standard SBM purchased on the open market in the United States was used in all experiments as a control. Data from pigs fed a low-protein casein diet in each study were used to calculate true AA digestibilities. Pigs were fitted with simple T-cannulas at the terminal ileum and allotted to treatments in Latin square design experiments. Duplicate experiments were conducted at the University of Illinois and at The Ohio State University. Within each country comparison, pigs fed the SBM processed in the U.S. from SB grown in the five countries had lower (P < 0.05) true total amino acid (TAA) digestibilities than did pigs fed any of the SBM prepared within the country of origin, except the United States. This indicates that processing conditions used at the U.S. pilot plant were not ideal when using SB from other countries. True TAA digestibilities of the diets containing the high-, intermediate-, and low-quality SBM did not differ, except for China, where the low-quality SBM (83.5%) had a lower (P < 0.05) digestibility than the intermediate- (89.6%) or high- (89.0%) quality meals. Soybean meal produced in Argentina (average, 87%) and Brazil (average, 82%) had lower (P < 0.05) true TAA digestibilities than did the standard SBM (91%), indicating that the processing plants in those countries may produce a less digestible SBM than that available on the open market in the United States.  相似文献   

11.
Plant-based protein sources are generally less variable in chemical composition than animal-based protein sources. However, relatively few data are available on the nutrient digestibilities of plant-based protein sources by companion animals. The effects of including selected soybean protein sources in dog diets on nutrient digestion at the ileum and in the total tract, as well as on fecal characteristics, were evaluated. Six protein sources were used: soybean meal (SBM), Soyafluff 200W (soy flour), Profine F (traditional aqueous-alcohol extracted soy protein concentrate [SPC 1]), Profine E (extruded SPC [SPC 2]), Soyarich I (modified molecular weight SPC [SPC 3]), and poultry meal (PM). All diets were extruded and kibbled. Test ingredients varied in CP and fat contents; however, diets were formulated to be isonitrogenous and isocaloric. Nutrient intakes were similar, except for total dietary fiber (TDF), which was lower (P < 0.01) for dogs fed the PM diet. Apparent ileal digestibilities of DM, OM, fat, and TDF were not different among treatments; however, CP digestibility at the terminal ileum was higher (P < 0.01) for diets containing soy protein sources than for PM. Total tract CP digestibility was greater (P < 0.01) for soy protein-containing diets than for PM. Apparent total tract digestibilities of DM, OM, fat, and TDF were not different among treatments. Apparent amino acid digestibilities at the terminal ileum, excluding methionine, threonine, alanine, and glycine, were higher (P < 0.01) for soy protein-containing diets than for PM. Dogs fed SPC diets had lower (P < 0.01) fecal outputs (g asis feces/g DMI) than dogs fed the SF diet, and dogs fed SBM tended (P < 0.11) to have lower fecal outputs than dogs fed the SF diet. However, dogs fed the PM diet had lower (P < 0.03) fecal outputs than dogs fed SPC-containing diets. Fecal outputs and scores reflected the TDF and nonstructural carbohydrate contents of the soy protein fraction. Soy protein sources are well utilized by the dog prior to the terminal ileum, and SPC offers a viable alternative to PM as a protein source in dry, extruded canine diets.  相似文献   

12.
The objective of this experiment was to determine whether the digestibility of CP and AA in a mixed diet fed to growing pigs is better predicted when based on standardized ileal digestibility coefficients (SID) or apparent ileal digestibility coefficients (AID). Eight growing pigs (initial BW = 92.1 +/- 3.19 kg) were surgically equipped with a T-cannula in the distal ileum and arranged in an 8 x 8 Latin square design with eight diets and eight periods. Three of the diets contained corn, soybean meal (SBM), or canola meal (CM) as the sole source of CP and AA. Four mixed diets also were formulated using corn and soybean meal (CS); corn and canola meal (CCM); soybean meal and canola meal (SCM); or corn, soybean meal, and canola meal (CSCM). A N-free diet was used to measure the basal ileal endogenous losses (IAAend) of CP and AA. Pigs were fed each of the eight diets during one 7-d period, and ileal digesta were collected during two 10-h periods on d 6 and 7. The AID values were calculated for CP and AA in all diets, except the N-free diet. By correcting the AID for IAAend, the SID for CP and AA in each of the seven protein-containing diets were calculated. As expected, the AID for CP and the majority of AA were greater in SBM than in corn and CM (P < 0.05); however, the SID for CP and most AA did not differ between corn and SBM. For the majority of the AA, SID were less (P < 0.05) in CM than in the other two ingredients. Using the AID and the SID that were measured for CP and AA in corn, SBM, and CM, the AID and the SID in the four mixed diets were predicted and compared with the measured values for these diets. For the three mixed diets containing corn, the measured AID for CP and most AA were greater (P < 0.05) than the predicted AID, but with a few exceptions, no differences between predicted and measured values for SID were observed. For the diet based on SCM, there were no differences between predicted and measured values regardless of the procedure used, except for the AID of Ser. The results of this experiment demonstrate that the digestibility coefficients for a mixed diet containing low-protein feed ingredients, such as corn, are more accurately predicted using SID than AID.  相似文献   

13.
The objective of this study was to evaluate dietary galactooligosaccharide (Gal OS) addition on swine nutrient digestibility, ileal and fecal bacterial populations, and ileal short-chain fatty acid (SCFA) production, and to determine their impact on ileal fermentative characteristics in vitro. Twelve T-cannulated pigs (BW = 25 kg) were fed a diet free of Gal OS for 21 d. On d 22, ileal digesta samples were collected for an in vitro fermentation experiment (Exp. 1). Substrates included: raffinose/stachyose combination (R + S), soy solubles (SS), and transgalactooligosaccharides (TOS). Also included were the non-OS components of SS and TOS. Nine pigs (three donors per treatment) served as ileal effluent donors. Each substrate was fermented in vitro for 6 h, and pH and SCFA and gas production were determined. Pigs then were allotted to three treatments: a Gal OS-free control diet and the control diet with either 3.5% added Gal OS from SS or TOS. Diets, feces, and digesta samples collected weekly for 6 wk on d 6 (feces) and 7 (digesta) were analyzed for DM, OM, CP, and chromic oxide concentrations. Feces and ileal digesta were analyzed for bifidobacteria and lactobacilli populations. Ileal digesta samples were analyzed for SCFA. On d 64, a second in vitro fermentation experiment (Exp. 2) was conducted using ileal effluent from three pigs per treatment and the same substrates used in Exp. 1. In vivo results showed that ileal and total tract DM and OM digestion were decreased (P < 0.05) by addition of both SS and TOS to the diet. Ileal and total-tract N digestibilities were decreased (P < 0.05) by dietary addition of SS. Fecal bifidobacteria and lactobacilli were increased (P < 0.05) by addition of SS and TOS to the diet. Ileal propionate and butyrate concentrations were greater (P < 0.05) for pigs fed diets containing both sources of Gal OS. In vitro results showed that fermentation data were not affected by donor animal adaptation to treatment. For both in vitro experiments, gas and SCFA production were higher (P < 0.05) for R + S than for SS or TOS. Fermentation of R + S resulted in a higher pH (P < 0.05) than did SS or TOS. Fermentation of non-OS components of SS and TOS resulted in more (P < 0.05) gas and SCFA production, and pH values that did not differ (P > 0.05) compared to SS and TOS. The Gal OS used in this study were prebiotics, increasing beneficial bacteria in vivo and SCFA concentrations both in vivo and in vitro.  相似文献   

14.
Six ileal-cannulated pigs that averaged 100 kg BW and 16 adult cecectomized cockerels that averaged 2.35 kg BW were used to determine apparent and true digestibilities of amino acids (AA) in a complete crystalline AA mixture and in casein. A protein-free (PF) diet was included as a treatment to estimate endogenous AA losses. Fasted cockerels were compared to cockerels fed PF diets for calculation of true digestibility of AA in cockerels. For the AA diet, true digestibility of indispensable AA in the pig ranged from a low of 97.2% for leucine to a high of 100.5% for arginine (Arg). True digestibility of indispensable AA in casein ranged from a low of 93.5% for isoleucine (Ile) to a high of 99.9% for Arg. Correcting for endogenous losses increased digestibilities of lysine (Lys) and threonine (Thr) in pigs fed the AA diet by 2.4 and 7.1%, respectively, and increased Lys and Thr digestibility in pigs fed the casein diet by 1.8 and 6.1%, respectively. Feeding a PF diet to chickens to correct for endogenous losses resulted in higher true digestibility values for all AA with the exception of tryptophan, methionine, and Arg than those obtained using fasted animals. True digestibilities of Thr were 88.3 and 86.6% for AA and casein diets, respectively, using fasted controls but were 97.5 and 94.5% when the PF control was used. Proline digestibility was increased (P < .05) substantially in both pigs and cockerels when the PF control was used to correct for endogenous AA losses. Regardless of species, Ile in casein had a lower true digestibility value than any other indispensable AA. The results of this study indicated that true digestibilities of AA in a mixture of crystalline AA and in casein are essentially 100% in both pigs and cockerels.  相似文献   

15.
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   

16.
试验比较了不同热处理时间大豆片、普通豆粕和去皮豆粕在生长猪回肠表观和真消化率的影响。试验采用12头回肠末端安装简单T型瘘管的生长猪,6×6有重复拉丁方设计。采用玉米淀粉-豆粕半纯合型日粮,配制酪蛋白日粮用以测定内源氮和氨基酸的损失量。结果表明:随着大豆片热处理时间的延长(0～18min),粗蛋白质和氨基酸的回肠表观和真消化率均显著提高(线性效应,P<0.01)。生大豆片的粗蛋白质和氨基酸的消化率显著低于普通豆粕和去皮豆粕(P<0.01),但普通豆粕与去皮豆粕间差异不显著(P>0.05)。  相似文献   

17.
Heat treatment of soybean meal (SBM) is necessary to reduce the concentration of trypsin inhibitors, but excessive heat treatment may reduce AA concentration and digestibility because AA can be destroyed by the Maillard reaction. The objective of this experiment was to determine the effects of heat treatment of SBM on apparent ileal digestibility and standardized ileal digestibility (SID) of AA by growing pigs. A source of conventional dehulled SBM (48.5% CP) was divided into 4 batches. One batch was not additionally heated, 1 batch was autoclaved at 125°C for 15 min, 1 batch was autoclaved at 125°C for 30 min, and 1 batch was oven-dried at 125°C for 30 min. Four SBM-cornstarch diets were formulated, and each of the 4 batches of SBM was used as the sole source of dietary AA in 1 diet. A N-free diet was used to estimate basal endogenous losses of AA. Ten growing barrows with an initial BW of 25.3 ± 2.0 kg were individually fitted with a T-cannula in the distal ileum. Pigs were allotted to treatments in a replicated 5 × 5 balanced Latin square design with 5 diets and 5 periods. Each period lasted 7 d, and ileal digesta were collected on d 6 and 7 of each period. Results of the experiment indicated that the apparent ileal digestibility and SID of CP and all AA decreased linearly (P < 0.01) as the time of autoclaving increased from 0 to 30 min. The concentration of furosine and the color of samples of SBM indicated that autoclaving resulted in a Maillard reaction in the SBM. However, oven drying at 125°C for 30 min did not change (P > 0.10) the SID of CP and AA in the SBM or the furosine concentration, and the color in the oven-dried sample indicated that this sample was not heat damaged. In conclusion, the digestibility of all AA in autoclaved SBM is linearly reduced as the autoclaving time increases from 0 to 30 min. The reason for these changes is most likely that autoclaving at 125°C results in Maillard reactions in SBM.  相似文献   

18.
We explored the suitability of Goettingen Minipigs as models to measure ileal AA digestibility and evaluate dietary proteins for conventional pigs. Further, a potential for secondary ileal microbial colonization 5 mo after establishing end-to-end ileorectal anastomosis was investigated. Goettingen Minipigs (BW 18 kg) and Saddleback pigs (BW 27 kg) fitted with end-to-end ileorectal anastomosis were fed six diets based on barley and oilseed meals and three diets based on wheat and milk powder differing in total and ileal digestible lysine. Apparent ileal digestibilities of CP (N x 6.25) and of 20 AA were determined. No differences (P = 0.062 to 0.982) were found in AA apparent ileal digestibilities between breeds. Therefore, Minipigs are a reasonable model to estimate apparent ileal digestibility of AA for evaluation of dietary proteins. However, the apparent ileal digestibility of CP (P = 0.048) was higher in Minipigs than in Saddleback pigs (barley and oilseed meals-based diets 70% vs. 66%; wheat and milk powder-based diets 80% vs. 77%), which is probably due to a smaller contribution of non-AA-nitrogen in the ileal effluent of Goettingen Minipigs. For lysine, the apparent ileal digestibilities (means of both breeds) ranged from 78 to 85% in wheat and milk powder-based, and 70 to 78% in barley and oilseed-based diets. Experimentally derived concentrations of ileally digestible lysine confirmed the values predicted from a published table. Microbial counts were not affected by breed as shown for lactobacilli, with 9.1+/-0.2 and 9.1+/-0.2 (P = 0.977), enterococci with 4.8+/-0.3 and 5.6+/-0.4 (P = 0.162), and yeasts with 4.6+/-0.3 and 4.6+/-0.4 (P = 0.906) log cfu/g effluent for Goettingen Minipigs and Saddleback pigs, respectively. The counts did not change over 5 mo, suggesting that no secondary microbial colonization occurred in pigs with end-to-end ileorectal anastomosis.  相似文献   

19.
An experiment was carried out to investigate the variability in apparent ileal amino acid (AA) digestibilities in simulated samples of wheat shorts consisting of different proportions of wheat bran (WB), wheat shorts (WS), and wheat flour (WF), hereafter referred to as wheat fractions. The proportions of WS, WB, and WF and the NDF content (DM basis) of the wheat fractions were as follows: A, 70% WS, 30% WB, and 42.3% NDF; B, 85% WS, 15% WB, and 41.8% NDF; C, 100% WS and 41.3% NDF; D, 85% WS, 15% WF, and 35.2% NDF; and E, 70% WS, 30% WF, and 29.5% NDF. Six barrows, average initial BW of 37.2 kg, fitted with a simple T-cannula at the distal ileum, were fed one of six experimental diets according to a 6 x 6 Latin square design. Six diets were formulated to contain 17% CP (as-fed basis). Diets A, B, C, D, and E contained 17.53% soybean meal (SBM), which contributed 50% of the CP in these diets. The wheat fractions contributed the remaining 50% of the CP in these diets. Diet F contained 35.05% SBM, which was the sole source of dietary CP. Chromic oxide was used as the digestibility marker. During the first experimental period, the daily dietary allowance was provided at a rate of 5% (wt/wt) of the average BW. Thereafter, the daily dietary allowance was increased by 100 g at each successive period. Each experimental period comprised 12 d. Following a 7-d adaptation period, feces were collected for 48 h and ileal digesta for a total of 24 h. The apparent ileal digestibilities of AA in the wheat fractions were calculated using the difference method. The digestibilities were usually lowest in the wheat fractions containing WB and highest in those containing no WB. The average of the digestibilities of the indispensable AA was 63.5% for wheat fraction A, which contained 30% WB, and 71.9% for wheat fraction C, which did not contain WB. There were no differences (P > .05) in lysine digestibilities among the wheat fractions, which ranged from 54.7 to 64.1%. Of the indispensable AA, with the exception of arginine, lysine, and methionine, the apparent ileal digestibility values of AA were negatively correlated (P < .05) with the NDF content in the wheat fractions.  相似文献   

20.
Wheat by-products are feedstuffs that vary in nutritional value, partly because of arabinoxylans that limit nutrient digestibility. Millrun is a byproduct from dry milling wheat into flour and contains varying amounts of the bran, middlings, screening, and shorts fractions. The digestible nutrient content of mill-run is not well known. Effects of xylanase supplementation (0 or 4,000 units/kg of diet) on energy, AA, P, and Ca digestibilities were studied in a wheat control diet and 5 diets containing 30% of a by-product (mill-run, middlings, shorts, screening, or bran) in a 2 x 6 factorial arrangement of treatments. The wheat control diet was formulated to contain 3.34 Mcal of DE/kg and 3.0 g of standardized ileal digestible Lys/Mcal of DE. Diets contained 0.4% chromic oxide. Each of 12 ileal-cannulated pigs (32.5 +/- 2.5 kg) was fed 6 or 7 of 12 diets at 3 times the DE requirement for maintenance in successive 10-d periods for 6 or 7 observations per diet. Feces and ileal digesta were each collected for 2 d. Xylanase tended to increase (P < 0.10) ileal energy digestibility by 2.2 percentage units and the DE content by 0.10 Mcal/kg of DM and increased (P < 0.05) ileal DM digestibility by 2.8 percentage units; a diet x xylanase interaction was not observed. Xylanase increased (P < 0.05) total tract energy and DM digestibilities and the DE content. A diet x xylanase interaction was observed; xylanase increased (P < 0.05) total tract energy digestibility of the millrun diet from 72.1 to 78.9%, DE content from 3.19 to 3.51 Mcal/kg of DM, and DM digestibility from 71.5 to 78.6%. Diet affected (P < 0.05) and xylanase improved (P < 0.05) digestibility and digestible contents of some AA in diets and by-products, including Lys, Thr, and Val. Xylanase increased (P < 0.05) Lys digestibility by 13.8, 5.0, 5.2, 6.0, and 14.1 percentage units in millrun, middlings, shorts, screening, and bran, respectively. Diet affected (P < 0.01) total tract P and Ca digestibilities. Xylanase increased (P < 0.05) digestible P and Ca contents. In summary, nutrient digestibility varies among wheat by-products. Millrun contained 2.65 Mcal of DE/kg of DM, which xylanase increased to 3.56 Mcal of DE/kg of DM. Xylanase improved nutrient digestibility and DE content in wheat by-products; and the extent of improvement depended on the by-product. Xylanase supplementation may maximize opportunities to include wheat byproducts in swine diets and ameliorate reductions in nutrient digestibility that may be associated with arabinoxylans.  相似文献   

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