猪对不同类型谷物饲料回肠末端氨基酸消化率比较测定

猪饲料营养价值的评定，是合理选择饲料原料，配制全价、平衡、适用日粮的基础，也是养猪生产取得效益的关键。饲料中氨基酸的可利用性的测定一直是动物营养学家的重要研究课题。近年来，国内外学者在猪饲料氨基酸生物学效价的评定方法上已取得重要进展，其中采用回－直肠吻合术的回肠末端氨基酸消化率测定法以其准确性、可操作性的优点，被认为是表征猪饲料氨基酸生物学效价的最适宜方法。据此，本研究采用该法评定了高蛋白糙米、普通玉米、普通糙米及普通稻谷的回肠末端氨基酸消化率，比较评价４类谷物类型饲料蛋白质营养价值优劣。１材料…     

鲁梅克斯K-1草粉猪氨基酸回肠真消化率的测定

选用8头平均体重为(35.5±1.5)kg去势公猪(约克夏×长白×北京黑),分别在回肠末端安装简单T型瘘管,待恢复10d后,挑选其中恢复良好的5头猪,根据5×5拉丁方设计,分别饲喂5种以玉米淀粉为基础配制成的半纯合日粮。其中4种玉米淀粉—豆粕型日粮分别包括39.0%,37.1%,35.1%和31.2%的豆粕及0,5%,10%和20%的鲁梅克斯K-1草粉。第5种日粮为酪蛋白日粮,用于测定内源氨基酸的排出量。分别采用差减法和回归法比较测定了鲁梅克斯K-1草粉氨基酸回肠真消化率。结果表明,随着日粮中鲁梅克斯K-1草粉含量的增加,除组氨酸、缬氨酸和丙氨酸外,其它氨基酸及粗蛋白质的回肠真消化率均显著降低(P<0.05)。当利用差减法测定鲁梅克斯K-1草粉的氨基酸消化率时,其可靠性随着鲁梅克斯K-1草粉在日粮中比例的提高而提高,当鲁梅克斯K-1草粉在日粮中的含量较高时(20%的鲁梅克斯K-1草粉),利用差减法和回归法测得鲁梅克斯K-1草粉粗蛋白质或氨基酸的回肠真消化率没有显著差异。     

Standardized ileal protein and amino acid digestibility by growing pigs and sows

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.     

Dietary protein level affects nutrient digestibility and ileal microbiota structure in growing pigs

This study aimed to determine whether dietary protein content influences pig health as indicated by ileal microbiota structure and coefficients of total tract apparent digestibility (CTTAD) of nutrients. Seventy‐two gilts, with an initial body weight of 29.9 ± 1.5 kg, were used in this 42‐day feeding study. Pigs were randomly allotted to one of three dietary treatments of corn‐soybean meal contained 14, 16 or 18% crude protein (CP). As dietary CP content decreased, the CTTAD of most essential amino acids (AAs), except for arginine and histidine, increased linearly, while those of most nonessential AAs decreased linearly. The concentration of total short‐chain fatty acids (SCFA) was higher in pigs fed the diet with 14% CP content than others. Ileal microbiota structure was changed by dietary treatments. In particular, at the phylum level, the relative abundance of Tenericutes in ileal digesta decreased as the dietary protein content reduced, while that of cyanobacteria increased. At the genus level, the relative abundance of Weeksella, Phaseolus acutifolius, Slackia, Sulfurimonas and Aerococcus showed significant differences among the three dietary treatments. In conclusion, ileal microbiota structure was changed by dietary protein content. Moderate reduction of protein intake can benefit gut health by enhancing the gut microbial fermentation and SCFA formation.     

Determination of basal ileal endogenous losses and standardized ileal digestibility of amino acids in barley fed to growing pigs

Background: Basal ileal endogenous amino acid(AA) losses(IAA_(end)) and standardized ileal digestibility(SID) values of cereal grains, such as barley, are apparently underestimated when determined according to the nitrogen(N)-free method. Regression analysis between the dietary apparent ileal digestible content(c AID) and total crude protein(CP) and AA can be considered as alternative approach to obtain more accurate values for IAA_(end)and SID of AA in cereal grains.Methods: Eight hulled barley genotypes were used, with barley being the only source of CP and AA in the assay diets. The diets contained 95 % as-fed of these eight barley genotypes each, ranging in CP content between 109.1 and 123.8 g/kg dry matter(DM). Nine ileally T-cannulated barrows, average body weight(BW) 30 ± 2 kg, were allotted to a row-column design comprising eight periods with 6 d each and nine pigs. On d 5 and the night of d 6 of every period, ileal digesta were collected for a total of 12 h. The IAA_(end) and the SID were determined by linear regression analysis between c AID and total dietary CP and AA.Results: There exist linear relationships between cA ID and total CP and AA(P 0.001). The IAA_(end) of CP, Lys, Met, Thr and Trp amounted to 35.34, 1.08, 0.25, 1.02 and 0.38 g/kg DM intake(DMI), respectively, which are greater compared to average IAA_(end) determined previously under N-free feeding conditions. The SID of CP, Lys, Met, Thr and Trp was 90,79, 85, 79 and 86 %, respectively, and was greater when compared to tabulated values. Moreover, these SID values were greater than those reported in literature, based on correction of apparent ileal digestibility(AID) of CP and AA for their IAA_(end)values. Summarized, the results of the present regression analysis indicate greater IAA_(end)in barley-based diets compared to those obtained by N-free feeding.Conclusions: For low-protein feed ingredients like barley the regression method may be preferred over correction of AID values for their IAA_(end)determined under N-free feeding conditions, as intercepts and slopes of the linear regression equations between cA ID and total dietary CP and AA provide direct estimates of IAA_(end)and SID of CP and AA in the presence of the assay feed ingredient.     

生长猪对饲料原料中磷的消化率

磷是生长猪的一种重要营养素,但它总是不能被猪完全利用,因为其经常与植酸结合在一起。使用标准全肠道消化率（Standard Total Tract Digestibility,STTD）概念,可以更好地测定饲料原料中磷的准确营养价值。豆粕是猪饲料中一种优质蛋白质原料,由于全球猪鸡的饲养规模不断扩大,大豆的需求量快速增加,大大超过了其供应量。因此,一些其它来源的蛋白质原料有时会用于饲料中,以向动物提供一些必需氨基酸。     

精油对生长猪蛋白质和氨基酸等回肠末端表观消化率的影响

试验旨在通过采用T型瘘管法,研究精油对生长猪蛋白质和氨基酸等回肠末端表观消化率的影响。试验选用6头(杜×长×大)去势公猪([28.6±1.3)kg],采用3×3双拉丁方试验设计,分别饲喂正对照日粮:玉米-豆粕型基础日粮+抗生素;负对照日粮:无抗基础日粮;精油组日粮:负对照+0.01%精油。每个试验期为7 d,前5 d为适应期,后2 d为食糜收集期。结果表明,在日粮中添加精油可提高(P<0.05)蛋白质、能量、精氨酸、赖氨酸、亮氨酸、色氨酸、蛋氨酸、丙氨酸、总必需氨基酸、总氨基酸的回肠末端表观消化率,并有提高干物质、苏氨酸、天冬氨酸、丝氨酸和酪氨酸表观消化率的趋势(P<0.10)。在日粮中添加0.01%的精油可提高生长猪蛋白质、能量、总必需氨基酸和总氨基酸的回肠末端表观消化率,并有提高干物质表观消化率的趋势。     

Dietary galactooligosaccharides affect ileal and total-tract nutrient digestibility, ileal and fecal bacterial concentrations, and ileal fermentative characteristics of growing pigs

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.     

Neutral detergent fiber increases endogenous ileal losses but has no effect on ileal digestibility of amino acids in growing pigs

Two experiments were conducted to determine the effect of neutral detergent fiber (NDF) on endogenous amino acids and protein ileal losses; and also apparent ileal digestibility (AID), and standardized ileal digestibility (SID) of amino acids and crude protein. Sixteen barrows were fed four protein‐free diets containing graded NDF levels in Experiment 1. NDF was a mixture of sugarcane bagasse and corn leaves (SBCL). Twenty‐four barrows were fed diets with soybean protein concentrate (SPC) or casein as protein sources and SBCL or corncobs (CC) as NDF sources in Experiment 2. In Experiment 1, a linear increase (P < 0.05) in endogenous amino acid and protein ileal losses was observed with increased NDF levels, except for arginine, histidine, methionine and proline. In Experiment 2, protein (P < 0.001) and NDF (P < 0.01) sources significantly affected AID of dry matter, which was higher in casein diets (71.7%) and CC diets (70.7%). Protein and NDF sources significantly affected (P < 0.05) SID of crude protein, which was higher in casein diets (92.8%) and CC diets (92.7%). NDF source had no effect (P > 0.05) on SID of amino acids. Overall, this study showed that NDF increased endogenous amino acid and protein ileal losses, but did not affect ileal digestibility of amino acids.     

生长猪回肠氨基酸消化率的标准化测定方法

根据荷兰CVB(1996)和德国GfE(2002、2005)的最新规定,提出了生长猪回肠氨基酸消化率测定的一个标准化方法。本文从①试验动物、猪舍环境和饲喂条件,②消化糜的收集及处理,③回肠氨基酸消化率测定方法三个方面比较了这些规定之间的差异和相似性。     

Standardization of methods for the determination of ileal amino acid digestibilities in growing pigs

Based on current recommendations of the CVB (1996) in the Netherlands and the GfE (2002, 2005) in Germany, a standardization of methods for the determination of ileal amino acid digestibilities in growing pigs is proposed. Differences and similarities between these protocols in terms of (i) animals, housing and feeding conditions (ii), methods for digesta collection and handling, and (iii) approaches to determine ileal amino acid digestibilities are described.     

Apparent and standardized ileal digestibility of amino acids in diverse barley cultivars fed to growing pigs

The objectives of this study were to determine the chemical composition, ileal amino acid (AA) digestibility of barley varieties and to develop equations to predict the AA digestibility based on the chemical characteristics of individual barley. A wide selection of nine barley varieties in the main growing regions of China was used in the experiment. Ten crossbred pigs (30.9 ± 1.8 kg) were allotted to a 6 × 10 Youden Square. The treatments included a nitrogen‐free diet and nine barley test diets. Considerable variation was observed in the content of neutral detergent fiber, acid detergent fiber, crude protein (CP) and all AAs among the barley samples. The standardized ileal digestibility (SID) of indispensable AAs with the exception of arginine, phenylalanine and threonine were different (P < 0.05) among the nine barley sources tested. With R² values exceeding 0.50, significant linear regression equations for CP and threonine were obtained. In conclusion, significant differences existed in the ileal digestibility of CP and AAs among barley varieties. It is difficult to predict the SID of most of the amino acids in barely based upon chemical characteristics.     

Nitrogen balance and ileal amino acid digestibility in growing pigs fed diets reduced in protein concentration

Two studies were conducted to assess the effect of dietary protein reduction on N utilization, N excretion, and AA digestibility in growing pigs. The objective was to determine whether pigs fed diets with a reduced CP concentration could maintain the same N retention as pigs fed an adequate diet. The second objective was to test whether reducing dietary CP concentration decreases AA digestibility. In each study, six barrows were allotted to one of six dietary treatments in a Latin square design. Treatments consisted of four corn-soybean meal-based diets containing 15, 12, 9, and 6% CP, a casein-based diet containing 15% CP, and a protein-free diet. Crystalline AA were included in the 12, 9, and 6% CP diets. The indispensable:dispensable AA ratio was maintained at 45:55 with the addition of L-glutamic acid to the 9 and 6% CP diets. The casein-based and protein-free diets were used to determine endogenous total tract N and ileal AA losses. In the first study, total N losses and N absorbed decreased linearly (P < 0.001) as dietary CP concentration decreased from 15 to 6%. Both a linear (P < 0.001) and a quadratic (P < 0.05) decrease in N retention were found with decreasing dietary CP concentration. Nitrogen retained as a percentage of intake and absorbed increased (P < 0.001) as dietary CP concentration was reduced from 15 to 6%. In the second study, six barrows were surgically fitted with a T-cannula at the terminal ileum to determine ileal AA digestibility. For all dispensable and most indispensable AA, apparent and standardized ileal digestibility increased linearly (P 0.01, and for arginine, P < 0.05) as dietary CP concentration decreased. These results indicate that dietary CP concentration can be decreased from 15 to 12% with crystalline AA supplementation to meet an ideal AA profile without adversely affecting N retention, and that decreasing dietary CP concentration from 15 to 6% increases both dispensable and indispensable AA ileal digestibility.     

True ileal amino acid digestibility and endogenous ileal amino acid losses in growing pigs fed wheat shorts- or casein-based diets

Use of dietary AA in growing pigs reflects digestion and use of digested AA for various body functions. Before evaluating dietary effects on use of digestible AA intake for body protein deposition, a digestibility study was conducted to investigate true ileal AA digestibility and endogenous ileal AA losses in growing pigs fed graded levels of wheat shorts (WS) or casein (CS; control). A casein-based basal diet (basal) was formulated to contain 0.27 g of standardized ileal digestible (SID) Lys per MJ of DE, to which extra Lys was added from WS (WS2, +0.10 g of SID Lys per MJ of DE; WS3, +0.20 g of SID Lys per MJ of DE) or casein (CS3, +0.20 g of SID Lys per MJ of DE). A fifth diet was formulated to be similar in CP level and source as CS3 but in which 6% pectin, a source of soluble non-starch polysaccharides (NSP), was included at the expense of cornstarch (CS3 + pectin). Five Yorkshire barrows (17.5 +/- 1.5 kg of BW) were fitted with a T-cannula at the distal ileum and randomly assigned to 1 of the 5 experimental diets in a 5 x 5 Latin Square design. Apparent ileal digestibility (AID), true ileal digestibility (TID), and endogenous ileal protein losses (EPL) were determined using the homoarginine method. Diet CS level did not influence (P > or = 0.10) TID of most essential AA or EPL (10.4 g/kg of DM intake). Including pectin in the diet did not influence TID of AA (P > or = 0.10) but increased EPL (15.6 g/kg of DM intake; P > or = 0.01). Inclusion of WS in the diet reduced TID of most essential AA (P < 0.01). The TID values for most essential AA, however, were the same (P > or = 0.10) for both dietary WS levels, except for Lys and Met, which were further reduced at the greatest dietary WS level. Increased EPL (P < 0.01) was only observed for WS3 (16 g/kg of DMI). We concluded that (1) the effects of dietary protein source on AID of AA can be attributed both to reduced TID of AA and increased EPL, (2) the impact of dietary WS level on TID of AA and EPL does not seem to be linear, (3) soluble NSP from pectin or WS exerts a greater effect on EPL than insoluble NSP, and (4) because of the metabolic cost associated with EPL and the impacts of feed composition on microbial fermentation in the gut lumen, the effects of feed ingredients on the use of ileal digestible AA for protein deposition should be investigated further.     

Influence of phytase and xylanase supplementation of a wheat-based diet on ileal and total tract digestibility in growing pigs

The effect of phytase and xylanase supplementation of a wheat-based pig diet on the ileal and total tract apparent digestibility of dietary components and minerals were studied in eight growing pigs fitted with a PVTC cannula in a randomized block design experiment. The diets (A and B) were similar in major ingredient composition and in nutrient content. In diet A, part of the limestone was replaced with di-calcium phosphate to increase the content of available phosphorus (P). Diet B was fed without or with supplementation with phytase (500 FTU/kg; diet BP), xylanase (4000 XU/kg; diet BX) and phytase + xylanase (500 FTU and 4000 XU/kg; diet BPX). There were no differences (P > 0.05) between diets in the ileal or total tract digestibility of organic matter (OM), NDF and crude protein (CP). The ileal and total tract digestibility for P and Ca differed (P < 0.05) between diets, while there were no treatment effects for Zn. The ileal and total tract digestibility for P and Ca was higher (P < 0.05) on diets BP and BPX than on the other diets. In conclusion, phytase improved the utilization of dietary P and Ca in a wheat-based diet, while xylanase had no additional benefits in terms of OM and CP digestibility or mineral utilization. Phytase had no effect on the digestibility of OM, CP or NDF.     

Additivity of values for apparent and standardized ileal digestibility of amino acids in mixed diets fed to growing pigs

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.     

Standardized ileal digestibility of amino acids in European soya bean and rapeseed products fed to growing pigs

This study was conducted to determine the chemical composition and standardized ileal digestibility coefficients (SID) of crude protein (CP) and amino acids (AA) of European soya bean and rapeseed products in pigs. Six soya bean and two rapeseed products were used as the sole dietary source of CP and AA, including raw (FFSB) and roasted full‐fat soya beans (FFSB_Roasted), soya bean (SBC) and rapeseed cake (RSC), and rapeseed meal (RSM) from Bavaria (Germany), soya bean meal (SBM) from the Danube region (Austria; SBM_Austria), a commercially available standard SBM (SBM_Std) and an imported genetically modified organism‐free SBM (SBM_GMO‐free). Eight ileal‐ cannulated pigs with an initial body weight of 32 ± 2 kg were allotted to a row‐column design with eight diets and six periods of seven days each. Trypsin inhibitor activity (TIA) ranged from 1.8 in SBM_Std to 24.5 mg/g DM in FFSB. The SID of CP and all AA in FFSB_Roasted were greater than in FFSB, but lower when compared to SBC and SBM_Austria (p < .05). The SID of CP and all AA (except glutamic acid) were not different between SBC and SBM_Austria, but the SID of CP and all AA (except methionine) were greater (p < .05) in SBC than in SBM_GMO‐free. Furthermore, the SID of CP and most AA showed a quadratic response with decreasing TIA, and there exists a quadratic response in SID of CP and all AA with increasing lysine to CP ratio and neutral detergent insoluble nitrogen (p < .05). In conclusion, variation in chemical composition and SID of CP and AA was observed in different European soya bean and rapeseed products as influenced by differences in processing conditions. European SBC and SBM_Austria can be used as alternative to imported SBM_GMO‐free and SBM_Std in diets for growing pigs.     

Effects of dietary supplementation of an enzyme blend on the ileal and fecal digestibility of nutrients in growing pigs

The objective of this experiment was to determine the effect of a beta-glucanase-protease enzyme blend product (EBP) on fecal digestibility (FD), apparent ileal digestibility (AID), standardized ileal digestibility, and digestibility in the hindgut of growing pigs. Twelve ileal-cannulated, growing barrows (38.2 +/- 0.5 kg) were housed in individual metabolism crates, blocked by previous feed intake into 3 groups with 4 pigs each, and randomly assigned to 1 of 4 treatments within a square (group) of 3 replications of 4 x 4 Latin square design. Treatments were basal diet (Basal), Basal + 0.05% of EBP (0.05% EBP), Basal + 0.10% of EBP (0.10% EBP), and hydrolyzed casein for measurement of endogenous amino acids. The Basal diet consisted of corn and soybean meal and was calculated to have 3.36 Mcal of ME/kg and 1.1% of total lysine, as-fed basis. Feed intake of each replicate of the Latin square during the first period was 85% of the minimum feed intake of the 4 pigs during the preliminary period and was equalized within each square. The feeding level was increased by 100 g/d in each subsequent period. Each of the experimental periods was 14 d, including 4 d of dietary adaptation, 5 d of fecal collection, 3 d of transition period, and 2 d of ileal collection. Ileal effluents were collected continuously for the same 12-h interval each day. Pigs fed the EBP demonstrated increased (P < 0.05) FD of DM, OM, energy, CP, nonfiber carbohydrate, total dietary fiber, insoluble dietary fiber, acid-hydrolyzed fat, ash, Ca, and P compared with pigs fed Basal. The AID of NDF and hemicellulose was increased (P < 0.05) by supplying the EBP either at 0.05 or 0.10% in the diets, but AID of DM and energy was not increased. The AID of acid-hydrolyzed fat tended to be greater (P = 0.051) for the pigs fed the EBP than for those fed Basal. Ileal digestibility of most amino acids was not affected by treatment, but the EBP reduced the apparent and standardized digestibility of methionine, alanine, and serine (P < 0.05). The difference between FD and AID of hemicellulose was lower (P < 0.05) for the pigs fed the EBP than for those fed Basal. These results demonstrated that the EBP fed to growing pigs improved the FD of DM, OM, energy, CP, nonfiber carbohydrate, total dietary fiber, acid-hydrolyzed fat, Ca, and P, and the AID of NDF and hemi-cellulose, but the standardized ileal digestibility of amino acids was not improved by supplying the EBP in corn-soybean meal-based diets of growing pigs.     

Determination and prediction of the apparent and standardized ileal amino acid digestibility in cottonseed meals fed to growing pigs

This experiment was conducted to evaluate the chemical composition and apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of amino acids (AA) in cottonseed meals (CSM) and to develop prediction equations for estimating AA digestibility for growing pigs based on the chemical composition and AA content of CSM. 10 CSM were collected from 10 provinces in China. 11 barrows (initial body weight: 34.4 ± 1.9 kg), fitted with an ileal T‐cannula, were allotted to 6 × 11 Youden square with 6 periods and 11 diets. The diets included one N‐free diet and 10 CSM test diets containing 40% CSM as the sole source of AA. The nitrogen‐free diet was used to measure the basal endogenous losses of CP and AA. The AID and SID for crude protein (CP), Lys, Met, Trp, and Thr among the 10 CSM differed (p < 0.05). With R² values exceeding 0.30, significant linear regression equations for CP, Lys, and Thr were obtained. The best fit equations for predicting the AID and SID of Lys were: AID of Lys = 82.94–0.65 neutral detergent fiber, with R² = 0.44, residual standard deviation (RSD) = 4.03 and p = 0.04; and SID of Lys = 135.34–1.01 neutral detergent fiber + 34.27 Thr – 58.06 Trp – 84.93 Met, with R² = 0.90, RSD = 1.42 and p = 0.01. In conclusion, the results of AID, SID and prediction equations could be used to evaluate the digestibility of CSM in growing pigs.     

The effect of source of fiber on ileal and fecal amino acid digestibility and bacterial nitrogen excretion in growing pigs.

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.