去盲肠鸡和正常鸡测定的饲料氨基酸消化率可加性比较

本研究以去盲肠鸡和正常鸡按Ｓｉｂｂａｌｄ的“ＴＭＥ”方法分别测定了皮大麦、蒸煮血粉、发酵血粉、水解复合蛋白、热喷胶原蛋白、国产鱼粉及其配合饲料Ｊ１和Ｊ２的氨基酸表观消化率（ＡＡＡＤ）和真消化率（ＴＡＡＤ）。并对两种试鸡所测上述饲料原料氨基酸的消化率及其可加性作比较。结果表明：（１）６种饲料原料的某些氨基酸表观消化率和真消化率，去盲肠鸡和正常鸡测值间存在显著差异（Ｐ＜０．０５）。（２）去盲肠鸡内源氨基酸排出量显著高于正常鸡（Ｐ＜０．０５）。（３）在以非常规蛋白质为主要补充蛋白质源时，以去盲肠鸡测得的真可消化氨基酸具有最好的可加性。说明测定鸡饲料氨基酸消化率以去盲肠鸡为试验动物较好     

对水解复合蛋白在鸡的氨基酸可消化性之评价

本研究分别用去盲肠鸡和正常鸡测定水解复合蛋白的表观氨基酸消化率（ＡＡＡＤ）和真氨基酸消化率（ＴＡＡＤ）。测得去盲肠鸡对该产品的总氨基酸表现消化率为６２．１％，真消化率为７２．３％，正常鸡对该产品的总氨基酸表观和真消化率分别为６３．５％和７１．４％，去盲肠鸡和正常鸡对多数氨基酸的表观消化率测值之间有显著差异（Ｐ〈０．０５），而大多数氨基酸的真消化率两种鸡的测值之间没有显著差异（Ｐ〉０．０５）。     

去盲肠鸡和未去盲肠鸡测定花生粕、胡麻粕、芝麻粕氨基酸消化率的研究

分别用２４只去盲肠和未去盲肠健康公鸡，测定了花生粕、胡麻粕和芝麻粕的氨基酸消化率。结果表明：去盲肠鸡内源氨基酸排泄量显著高于未去盲肠鸡（Ｐ＜０．０５）；在花生粕中，胱氨酸、赖氨酸、天冬氨酸和谷氨酸的ＡＡＤ未去盲肠鸡显著高于去盲肠鸡（Ｐ＜０．０５）；在胡麻粕和芝麻粕中，除酪氨酸和脯氨酸外，其它各种氨基酸及１６种氨基酸总和的ＡＡＡＤ和ＴＡＡＤ未去盲肠鸡显著高于去盲肠鸡（Ｐ＜０．０５）。鸡盲肠微生物对内源及饲料中未消化蛋白质、多肽及氨基酸具有分解作用，干扰饲料ＡＡＡＤ和ＴＡＡＤ测定。对于不易消化、氨基酸含量相对不平衡的低品质蛋白质饲料干扰尤其严重。在测定的３种饼粕中，花生粕氨基酸消化率最高，胡麻粕次之。过度热处理的芝麻粕氨基酸平均消化率为４７．３％，赖氨酸消化率为２１．７％。     

去盲肠鸡和未去盲肠鸡测定大豆粕、棉仁粕、菜籽粕氨基酸消化率的研究

分别用２４只去盲肠和未去盲肠健康公鸡，测定了豆粕、棉仁粕和菜籽粕的氨基酸消化率。试验结果表明：去盲肠鸡内源氨基酸排泄量显著高于未去盲肠鸡（Ｐ＜０．０５）；在大豆粕中，胱氨酸、苏氨酸等５种氨基酸的消化率未去盲肠鸡显著高于去盲肠鸡（Ｐ＜０．０５）；在棉仁粕和菜籽粕中，除个别氨基酸外，大多数氨基酸及氨基酸总和的消化率未去盲肠鸡显著高于去盲肠鸡（Ｐ＜０．０５），可见，饲料种类、试鸡有无盲肠均影响饲料ＡＡＡＤ和ＴＡＡＤ。盲肠微生物对内源及饲料中未消化蛋白质、多肽及氨基酸具有分解作用，干扰饲料ＡＡＡＤ和ＴＡＡＤ测定。对于不易消化，氨基酸含量相对不平衡的低品质蛋白质饲料干扰尤其严重。因此用去盲肠公鸡测定的饲料ＡＡＤ值更接近氨基酸在消化道内消化吸收的真实情况。     

鸡对THB活性酵母蛋白饲料的氨基酸可消化性研究

本研究对活性酵母饲料培养物ＴＨＢ进行氨基酸表现消化率（ＡＡＡＤ）和真消化率（ＴＡＡＤ）评定，去盲肠鸡的测定结果表明，ＴＨＢ活性酵母总氨基酸的ＡＡＡＤ和ＴＡＡＤ分别为８２．３％和９１．５％，与秘鲁鱼粉对应值７８．４％和９１．６％相比，ＡＡＡＤ值高３．９个百分点，ＴＡＡＤ值低０．１个百分点，其中赖氨酸，色氨酸，胱氨酸及甘氨酸等的ＴＡＡＤ比值进口鱼粉更显优势，研究表明ＴＨＢ活性酵母蛋白饲料的氨基酸消化率     

去盲肠鸡和未去盲肠鸡测定大豆粕,棉仁粕,菜籽粕氨基酸消化率的研究

分别用２４只去盲肠和未去盲肠健康公鸡，测定了豆粕、棉仁粕和菜籽粕的氨基酸消化率。试验结果表明：去盲肠鸡内源氨基酸排泄量显著高于未去盲肠鸡（Ｐ〈０．０５）；在大豆粕中，胱氨酸、苏氨酸等５种氨基酸的消化率未去盲肠鸡显著高于去盲肠鸡（Ｐ〈０．０５）；在棉仁粕和菜籽粕中，除个别氨基酸外，大多数氨基酸及氨基酸总和的消化率未去盲肠鸡显著高于去盲肠鸡（Ｐ〈０．０５），可见，饲料种类、试鸡有无盲肠均影响饲料ＡＡＡ     

去盲肠和未去盲肠公鸡氨基酸代谢率的比较研究

本研究应用Ｓｉｂｂａｌｄ强饲快速法，测定并比较了去盲肠和未去盲肠公鸡对３种蛋白质饲料氨基酸的代谢率，结果表明，未去盲肠鸡对３种蛋白质饲料的氨基酸表观和真代谢率均高于去盲肠鸡（Ｐ〈０．０５）。豆粕的氨基酸代谢率均高于其它２种蛋白质饲料（Ｐ〈０．０５），从总体来看，去盲肠和去盲肠公鸡豆粕的蛋氨酸（ＭＥＴ），酪氨酸（ＴＹＲ），组氨酸（ＨＩＳ）精氨酸（ＡＲＧ），胱氨酸（ＣＹＳ）等氨基酸的表观及真代谢率差异     

泰和鸡蛋氨酸表现消化率与真消化率的比较测定

准确测定饲料氨基酸消化率（ＡＡＤ）已成为动物营养学评定饲料氨基酸生物效价的主要研究课题之一。ｓｉｂｂａｌｄ建立的强饲法，用于测定饲料ＡＡＤ的方法，由于未考虑鸡盲肠微生物对饲料氨基酸消化率的影响，可能导致低估饲料ＡＡＤ。鸡盲肠是消化道微生物主要活动场所，对氨基酸有降解作用。用切除盲肠的鸡，进行氨基酸利用率的研究，更能真实反映饲料蛋氨酸（Ｍｅｔ）的利用率。本研究的目的，是通过测定去盲肠与不去盲肠的两组试验鸡内源Ｍｅｔ排泄量和Ｍｅｔ排泄量及所测饲料中Ｍｅｔ表观消化率和真消化率的差异，来探讨盲肠微生物主…     

直接法和差量法评定鱼粉对鹅的营养价值

本文以鱼粉为研究对象,研究直接法和差量法对测定鹅真代谢能（ＴＭＥ）、常规养分代谢率的影响,以评定鹅饲粮中鱼粉的营养价值。试验采用单因素完全随机设计,分别选取 ２６０日龄健康五龙鹅和青农灰鹅各 ４２只（公）,各设 ７个组,每组 ２个重复,每个重复 ３只鹅,单笼饲养。对照组采用直接法,饲粮中不添加玉米淀粉;６个试验组采用差量法,分别在饲粮中添加２０％、３０％、５０％、６０％、７０％、８０％的玉米淀粉替代鱼粉。代谢试验采用全收粪法。结果表明：１）与对照组（直接法）相比,采用差量法测得的五龙鹅和青农灰鹅品种内 ６个试验组的 ＴＭＥ及粗蛋白质（ＣＰ）、青农灰鹅的粗脂肪（ＥＥ）、部分氨基酸（ＡＡ）、粗纤维（ＣＦ）、中性洗涤纤维（ＮＤＦ）、酸性洗涤纤维（ＡＤＦ）的代谢率显著提高（Ｐ＜０．０５）。２）差量法组间比较的结果表明,五龙鹅和青农灰鹅 ７０％玉米淀粉组的 ＴＭＥ及 ＣＰ、ＥＥ、部分 ＡＡ、ＣＦ、ＮＤＦ、ＡＤＦ、钙（Ｃａ）、磷（Ｐ）的代谢率均显著高于其他各组（Ｐ＜０．０５）;８０％玉米淀粉组营养代谢率呈下降趋势（Ｐ＞０．０５）。３）青农灰鹅对鱼粉的 ＴＭＥ及 ＣＰ、ＥＥ、部分 ＡＡ的代谢率显著（Ｐ＜０．０５）或极显著（Ｐ＜０．０１）高于五龙鹅;五龙鹅的 ＮＤＦ、ＡＤＦ、ＣＦ的代谢率显著高于青农灰鹅（Ｐ＜０．０５）。由此可见,采用差量法测定鹅鱼粉的营养成分代谢率效果优于直接法,并且以 ７０％玉米淀粉的添加比例数据稳定性最好,且鹅饲粮中的鱼粉养分代谢率品种间存在差异。     

“活性鱼粉”替代进口鱼粉饲喂试验

本试验采用以血粉为主要原料发酵而成的“活性鱼粉”替代进口（秘鲁）鱼粉进行饲喂试验。经检测：“活性鱼粉”粗蛋白含量、氨基酸含量均与秘鲁鱼粉相当，维生素含量远高于秘鲁鱼粉。饲喂试验表明，完全替代秘鲁鱼粉可降低成本：蛋鸡５．９７％，肉猪７．７８％     

以去盲肠鸡测定发酵血粉和蒸煮血粉的氨基酸利用率

本研究以去盲肠鸡和改良的“ＴＭＥ”法测定了发酵血粉和蒸煮血粉的氨基酸利用率。结果表明，除蛋氨酸外，鸡对发酵血粉的氨基酸利用率显著高于蒸煮血粉（Ｐ＜０．０５）。发酵血粉是一种值得开发利用和推广的蛋白质饲料。     

去盲肠和未去盲肠公鸡测定饲料氨基酸消化率的比较研究

应用Sibbald“TME”方法,比较了去盲肠和未去盲肠公鸡对饲料氨基酸的消化率。试验测定了10种饲料的去盲肠和未去盲肠公鸡的氨基酸消化率。结果表明,未去盲肠鸡对10种饲料的氨基酸表观和真消化率均高于去盲肠鸡。轻度受热鱼粉、重度受热鱼粉、脱毒棉籽饼、未脱毒棉籽饼和豆饼的表观氨基酸消化率在去盲肠鸡和未去盲肠鸡之间存在显著差异(P<0.05),未受热鱼粉和芝麻饼的表观氨基酸消化率在去盲肠鸡和未去盲肠鸡之间不存在显著差异(P>0.05)。轻度受热鱼粉、重度受热鱼粉、豆饼的真氨基酸消化率在去盲肠鸡和未去盲肠鸡之间存在显著差异(P<0.05);未受热鱼粉、脱毒棉籽饼、未脱毒棉籽饼和芝麻粕的真氨基酸消化率在去盲肠鸡和未去盲肠鸡之间不存在显著差异(P>0.05)。去盲肠鸡内源氨基酸排出量显著高于未去盲肠鸡(P>0.05)。微生物对未消化食糜中的肽类、氨基酸具有降解作用。     

去盲肠与正常黄羽肉鸡对大米粉氨基酸消化率的比较研究

试验旨在测定大米粉氨基酸消化率的同时,探讨去盲肠与正常黄羽肉鸡对大米粉氨基酸消化率的影响。结果表明:大米粉中氨基酸表观消化率去盲肠鸡普遍高于正常鸡,丙氨酸、亮氨酸和赖氨酸差异显著(P<0.05);大米粉中氨基酸的真消化率亦普遍表现为去盲肠鸡高于正常鸡,丙氨酸差异显著(P<0.05),酪氨酸差异极显著(P<0.01)。大米粉的总氨基酸表观消化率和真消化率在两种试鸡间差异不显著(P>0.05)。去盲肠鸡的内源氨基酸排泄量大多数测值高于正常鸡,但差异不显著(P>0.05)。本试验建议用正常鸡的测定值表示黄羽肉鸡对大米粉的氨基酸消化率。     

鸡对饲料氨基酸有效利用率的研究

采用Sibbald“真代谢能”法测定饲料原料的氨基酸有效利用率。试验鸡分别强饲玉米、大豆粕和鱼粉 ,测定鸡强饲后的氨基酸排出量。结果表明 ,不同种类饲料原料的氨基酸利用率存在差异 ,玉米与大豆粕、鱼粉间差异显著 (P <0 0 5)。不同种类氨基酸之间利用率也有差异。 3种饲料原料的氨基酸真利用率均大于表观利用率 ,其中玉米的差异达到极显著水平 (P <0 0 1 ) ,表明内源性氨基酸对氨基酸利用率有影响 ,且这种影响随饲料原料中粗蛋白质水平的下降而增大。 3种饲料原料的氨基酸利用率在去盲肠鸡与正常鸡之间存在差异。盲肠微生物对饲料原料的氨基酸利用率有影响 ,且对不同种类氨基酸的影响有差异 ,这种影响不能通过内源性氨基酸的校正而消除。另外 ,内源性氨基酸的排泄量在去盲肠鸡大于正常鸡。表明内源性氨基酸也受到盲肠微生物的影响     

A comparison of ileal digesta and excreta analysis for the determination of amino acid digestibility in food ingredients for poultry.

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.     

Digestibilities of amino acids in soyabean, sunflower and groundnut meals, determined with intact and caecectomised cockerels

1. Three isonitrogenous diets were formulated in which soyabean (dehulled), sunflower (hulled) and groundnut (dehulled) meals were the sole protein sources. 2. 50 g of each diet was tube-fed to each of 24 intact and 24 caecectomised cockerels, which had been previously starved for 48 h. Excreta were collected, individually, for 48 h. The concentrations of amino acids in the diets and excreta were determined, and digestibility coefficients calculated. 3. Differences between intact and caecectomised birds for true digestibility evaluations reached significance for threonine, glycine and lysine only. Deamination of threonine and glycine, and synthesis of lysine, in the caeca was implied. 4. Neither the true digestibility of nitrogen, nor that of the sum of the amino acids differed between protein sources. 5. True digestibilities of most essential amino acids, considered individually, in sunflower and groundnut meals were similar to or greater than, those of soyabean meal. Exceptionally, lysine was more digestible in soyabean (0.879) than in sunflower (0.722) or groundnut (0.788) meals.     

Digestibilities of amino acids in maize, wheat and barley meals, determined with intact and caecectomised cockerels

1. Maize, wheat and barley meals, and a protein-free diet were each force-fed to 24 intact and 24 caecectomised adult cockerels. For each test, birds were starved of solid food for 48 h, fed, and then excreta collected for 48 h. 2. Quantities of nitrogen (N) and amino acids excreted after feeding the protein-free diet did not differ between intact and caecectomised birds. 3. True digestibility coefficients of N and amino acids did not differ between intact and caecectomised birds. 4. Differences between cereals in apparent digestibility of amino acids were inconsistent and more readily attributed to differences between amino acid intake than bioavailability. 5. Differences between cereals in true digestibility of amino acids were confined to higher values for N, aspartic acid, alanine and leucine in maize than in barley or wheat meals.     

Determination of amino acid digestibility using caecectomised and intact adult cockerels

Four subsamples of meat and bone meal (MBM) were heated (150 degrees C) for 0, 1.5, 3 and 5 h and then incorporated into four individual diets (100 g MBM/kg diet). The diets were precision-fed to 10 caecectomised and 10 intact adult cockerels. The apparent amino acid digestibility (ApAAD) and true amino acid digestibility (TAAD) of the diets were determined by analysis of the excreta. The digestibility coefficients measured using caecectomised birds were lower than those determined with intact birds. Coefficients of digestibility were statistically examined by analysis of variance for the effects of bird type (caecectomised or intact), type of calculation (apparent or true) and diet (heat-treatment) with and without accommodation for individual bird variability. If individual bird variability was not considered in the analysis the bird type X diet interactions (P less than 0.01) included glutamic acid, tyrosine and serine. When individual bird variability was included in the analysis, significant (P less than 0.01) bird type X diet interactions occurred for aspartic acid, serine, glutamic acid, leucine, tyrosine and lysine and the precision of the data was markedly improved. Amino acid digestibility using the precision-feeding procedure is affected by the selection of either intact or caecectomised birds.