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In this study, we examined the variations between the difference method and the enzyme-hydrolyzed casein method for determining endogenous amino acid loss and the true amino acid digestibility in ducks fed normal protein-containing diets. These methods were compared to the nitrogen-free (N-free) diet method. The difference method was based on soybean meal as the only protein source, with the experimental diets containing crude protein levels at 15% and 20%. The enzyme-hydrolyzed casein method was based on enzyme-hydrolyzed casein meal as the protein source, with the experimental diet containing a crude protein level of 17.5%. The N-free diet was prepared with starches and paper fibers. In each method, 64 Tianfu meat drakes (7-weeks-old) with an average body weight of 2.77 ± 0.16 kg were used and divided into four groups, and fed four different diets. Each group contained four replicates of four drakes and they were force fed trial diets according to the Sirbald method for detecting their apparent amino acid digestibility, endogenous amino acid loss and true amino acid digestibility. The results demonstrated that using the difference, enzyme-hydrolyzed casein and N-free diet methods, endogenous amino acid losses were 0.9946, 1.2243 and 0.9297 mg/g dry matter intake (DMI), respectively. The true amino acid digestibility measured by the difference method was 88.93% ± 4.43%. Using the enzyme-hydrolyzed casein method with two dietary crude protein levels of 15% and 20%, the digestibility was 91.15% ± 4.33% and 91.97% ± 4.16%, respectively, and by the N-free diet methods with two dietary crude protein levels of 15% and 20%, it was 88.55% ± 4.29% and 88.82% ± 4.61%, respectively. The results suggested that when the dietary protein level was 15% to 20 %, the true amino acid digestibility and endogenous amino acid loss as determined by the difference method was more accurate than the values determined by the enzyme-hydrolyzed casein method. 相似文献
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本试验研究了差量法和酶解酪蛋白法测定动物在采食正常含氮日粮条件下的内源氨基酸排泄量及饲料氨基酸真消化率的差异,并同时与无氮日粮法作比较。差量法以豆粕为唯一蛋白源,配制成15%和20%2种粗蛋白质水平的试粮;酶解酪蛋白法以酶解酪蛋白作为蛋白质来源,配制成17.5%粗蛋白质水平的试粮;无氮日粮用淀粉和纸纤维进行配制。每种方法选用7周龄、平均体重(2.77±0.16)kg天府肉公鸭64只,分为4组,分别饲喂4种不同日粮,每组4个重复,每重复4只鸭,采用Sibbald的强饲法进行代谢试验,测定各试粮氨基酸表观消化率、内源氨基酸排泄量及真消化率。结果显示:差量法、酶解酪蛋白法和无氮日粮法测定的内源氨基酸排泄量分别为0.9946、1.2243和0.9297mg/gDMI;差量法测定的氨基酸真消化率(%)为88.93±4.43,用酶解酪蛋白法和无氮日粮法测定的内源氨基酸排泄量计算的15%和20%2个粗蛋白质水平日粮氨基酸真消化率(%)分别为91.15±4.33和91.97±4.16、88.55±4.29和88.82±4.61。以上结果表明,在15%~20%的日粮蛋白质水平范围,差量法测定的氨基酸真消化率和内源氨基酸排泄量较酶解酪蛋白法准确,酶解酪蛋白法可能高估了内源氨基酸排泄量和氨基酸真消化率。 相似文献
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差量法测定鸭饲料氨基酸真消化率和内源氨基酸排泄量的研究 总被引:1,自引:0,他引:1
为了考察差量法测定氨基酸真消化率及内源氨基酸排泄量的可行性,用平均体重(3.0±0.1)kg、7周龄的天府肉公鸭(樱桃谷×建昌鸭)96只进行试验,设计6个试验日粮,蛋白质水平分别为0、5%、10%、15%、20%和25%。采用Sibbald的强饲法测定氨基酸的消化率,并同时用无氮日粮法、梯度回归法及饥饿法测定内源氨基酸的排泄量,计算各蛋白质水平日粮氨基酸的真消化率。试验结果表明,差量法测得各蛋白质水平段日粮氨基酸真消化率为(90.54±2.70)%、(90.62±1.88)%、(92.52±1.73)%、(92.73±1.77)%、(93.44±1.59)%和(92.37±1.09)%,在10%~20%的日粮蛋白质水平范围基本稳定。差量法、无氮日粮法、回归法和饥饿法测得日粮氨基酸真消化率平均值分别为(92.37±1.09)%、(92.65±0.56)%、(92.53±0.48)%和(89.15±2.02)%,其内源氨基酸排泄总量分别为0.233±0.015(6个蛋白质水平日粮平均值)、0.228、0.230和0.184g/(4只.h)。由此得知,差量法可用于测定饲料氨基酸的真消化率及内源氨基酸排泄量。 相似文献
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试验选取28周龄健康的罗曼公母鸡各16只,分别分为2个处理,每处理8个重复,每个重复1只鸡,分别饲喂2种试验日粮,即无氮日粮(NFD)和NFD+5%酪蛋白,比较分析2种方法测得的公母鸡内源氨基酸排泄量(EAAL)的差异。结果表明:采用NFD法和NFD+5%酪蛋白所得的公母鸡内源氨基酸和总蛋白质的排泄量有所不同。酪蛋白组能够增加内源氮和内源氨基酸的排泄量,NFD+5%酪蛋白法所测得的内源氮和内源氨基酸排泄量更接近试鸡的真实情况。2种测定方法公鸡内源氮和内源氨基酸的排泄量均高于母鸡的结果。 相似文献
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无氮日粮法与绝食法测定肉仔鸡内源氨基酸损失量的研究 总被引:1,自引:0,他引:1
本试验分别用无氮日粮法和绝食法测定肉仔鸡内源氨基酸损失量,并比较两种方法得到的结果之间的差异.选用49日龄健康的AA肉仔鸡公鸡20只,随机分成2组,每组10只,采用48 h空腹+48 h全收粪法进行试验.结果表明,无氮日粮法和绝食法测定的肉仔鸡内源氨基酸中,精氨酸、苏氨酸、胱氨酸、酪氨酸内源损失量之间无显著性差异(P>0.05);无氮日粮法测定的其他氨基酸内源损失量极显著(P<0.01)或显著(P<0.05)高于绝食法;无氮日粮法测定的总氨基酸内源损失量极显著(P<0.01)高于绝食法. 相似文献
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酪蛋白和无氮日粮对猪回肠内源氨基酸排出量的影响 总被引:6,自引:0,他引:6
采用平均体重为65±1.85kg的瘘管猪6头,研究酪蛋白日粮、无氮日粮中添加三氧化二铬(PF-Cr)或酸不溶灰分(PF-AIA)对猪回肠内源氨基酸排出量的影响。结果表明,酪蛋白组中,除Met、Phe、Pro外,几乎所有的内源氨基酸排出量均高于PF组;PF-Cr组和PF-AIA组之间内源氨基酸排出量差异不显著(P>0.05)。结论无氮日粮法低估了回肠内源氨基酸排出量,而日粮中添加肽类物质对内源氨基酸的排出有刺激作用;用酸不溶灰分代替三氧化二铬研究回肠内源氨基酸的排泄基本可行。 相似文献
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《The Journal of Applied Poultry Research》2006,15(1):89-93
In recent years, policies encouraging the production of ethanol have stimulated an enormous increase in the production of distillers dried grains with solubles (DDGS). The form of the ingredient that is becoming increasingly available differs from that of previous decades in that it is derived almost entirely from corn and is dried under less severe conditions. Seventeen DDGS samples were obtained from 6 different plants in the midwestern United States from 2002 to 2004. Each sample was analyzed for TMEn, and 8 representative samples were analyzed for total and digestible amino acids (AA) by the precision-fed rooster assay using conventional or cecectomized Single Comb White Leghorn roosters, respectively. Color [lightness (L*), redness (a*), and yellowness (b*)] of each DDGS sample was measured with a Minolta Chroma Meter CR-300. The TMEn ranged from 2,490 to 3,190 kcal/kg (86% DM basis) and had a mean of 2,820 kcal/kg. Variation was noted among samples, presumably reflecting differences in the original corn composition, fermentation, and disposition of solubles. Considerable differences were observed among the true AA digestibilities of the DDGS samples. Most samples were golden in color, and true AA digestibility values were relatively consistent among these samples. The average total concentration and digestibility coefficients of several most limiting AA for the 8 DDGS samples were as follows: Lys, 0.71% (70); Met, 0.54% (87); cystine, 0.56% (74); Thr, 0.96% (75), Val, 1.33% (80), Ile, 0.97% (83); and Arg, 1.09% (84). Correlations were found among digestible Lys, Thr, Arg, His, and Trp and the yellowness (b*) and lightness (L*) of the DDGS samples. In general, DDGS samples that were more yellow and lighter in color had higher total and digestible AA levels. The variation in TMEn and AA digestibility observed among samples strongly indicated that confirmatory analyses should be conducted prior to using samples from a new supplier. 相似文献
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无氮饲粮对肉鸡盲肠微生物菌群结构及内源氨基酸基础损失量的影响 总被引:1,自引:0,他引:1
本试验旨在研究无氮饲粮对14日龄和35日龄肉鸡盲肠微生物菌群结构及内源氨基酸基础损失量的影响。分别选用10日龄和31日龄罗斯(Ross)308雄性肉鸡,随机分为2个组:常规饲粮组和无氮饲粮组,每组5个重复,其中10日龄时每个重复12只鸡,31日龄时每个重复6只鸡,试验期均为4 d。结果表明:肉鸡14日龄和35日龄时,收粪法所得大多数氨基酸内源基础损失量均显著或极显著高于回肠食糜法(P<0.05或P<0.01)。相对常规饲粮,无氮饲粮改变了14日龄和35日龄肉鸡盲肠微生物16S rDNA V3高变区变性梯度凝胶电泳图谱的优势条带,其中14日龄和35日龄发生变化的优势条带灰度值占其整个优势条带总灰度值的比例分别为72%、39%。与常规饲粮相比,无氮饲粮对14日龄肉鸡盲肠食糜重、氨态氮浓度没有显著影响(P>0.05),但极显著降低了盲肠食糜中丁酸浓度(P<0.01),显著降低了异丁酸和戊酸浓度(P<0.05),极显著增加了丙酸浓度(P<0.01)。无氮饲粮组35日龄肉鸡盲肠食糜重极显著高于常规饲粮组(P<0.01),盲肠食糜氨态氮、乙酸、异丁酸、戊酸、异戊酸浓度则极显著降低(P<0.01)。综上所述,采用无氮饲粮测定内源氨基酸基础损失量时,收粪法所得大多数氨基酸内源基础损失量显著高于回肠食糜法。饲喂无氮饲粮4 d后,肉鸡盲肠食糜原有微生物优势菌群发生改变。 相似文献
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综述迄今所提出的内源氨基酸排泄量测定方法的基本原理及其优缺点。并将这些方法划分为3类,第1类是非正常生理条件下的测定方法,包括绝食法(FAS)、无氮日粮(NFD)法、NFD+合成氨基酸(AAs)、NFD+静脉注射AAs以及回归法(REG);第2类是接近生理条件下的测定方法,包括同位素标记内源氮法、同位素标记外源氮法、静脉1次注射小剂量[3H]Leu法、胍基化蛋白法、酶解酪蛋白/超滤法;第3类是体外/体内消化率差值法。 相似文献
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内源氨基酸排泄量(LEAA)是测定饲料氨基酸真消化率的重要指标,而同位素标记内源氮法是直接测定内源氨基酸排泄量的有效方法之一。本文综述了同位素标记内源氮法测定回肠内源氨基酸排泄量的基本原理、假设条件和影响因素。 相似文献
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试验比较了不同氨基酸模式对肉鸭生产性能的影响。将320只1日龄的樱桃谷鸭随机分为4组,每组80只,设4个重复,每个重复20只,公母各半,分别饲喂四种日粮(按四种氨基酸模式配制),试验期21天。结果表明:日粮的氨基酸模式为Lys∶Met∶Trp∶Thr=100∶45∶21∶62时,其2周和3周体重高于其它各组,但差异不显著(P>0.05),且F/G和血清尿酸水平最低。 相似文献
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用线性回归法(Linear Regression Analysis Technique,REG)测定生长公猪内源钙、磷排泄量和豆粕钙、磷的真消化率。选用6头大白×长白生长阉公猪为试验动物,平均初始体重为(28.6±1.76)kg。采用6×6拉丁方设计,以豆粕-玉米淀粉为基础,配制6个不同钙(0.04%、0.09%、0.13%、0.17%、0.22%、0.26%)、磷(0.09%、0.18%、0.27%、0.35%、0.44%、0.53%)水平的日粮。试验共6期,每期8d,预饲期6d,采样期2d。结果显示,以日粮干物质采食量(DMI)为基础,粪钙的排泄量随日粮钙的摄入量的增加而线性增加(P=0.002〈0.01),通过回归曲线法得出内源钙排泄量为0.6225g/kgDMI,豆粕钙真消化率为44.34%。以日粮干物质采食量(DMI)为基础,粪磷的排泄量随日粮磷的摄人量的增加而线性增加(P=0.025〈0.05),内源磷的排泄量为1.0771g/kgDMI,豆粕磷的真消化率为48.78%。结果表明,不同钙、磷水平的豆粕日粮,钙、磷的表观消化率变化较大,真消化率相对稳定。钙表观消化率平均比真消化率低41.50%,磷表观消化率平均比真消化率低35.51%。日粮配制时用钙、磷表观消化率会低估钙、磷生物学效价,造成钙、磷的过量添加和猪粪钙、粪磷排泄量的增加。因此,日粮配制时用钙、磷真消化率来评定钙、磷的生物学效价更精确。 相似文献
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为了获得最佳生产性能,配制满足家禽营养需要的日粮配方和将排泄到环境中的过多养分降到最低,已显得尤为重要。关于蛋白质饲料原料,多通过表观回肠消化率反映其利用率。以表观回肠消化率值为基础配制日粮,低估了饲料原料的氨基酸消化率,导致排泄物中养分含量增加。通过内源氨基酸基础损失校正表观回肠消化率所得的标准回肠消化率,能克服表观回肠消化率的局限性。作者讨论了标准回肠氨基酸消化率和内源氨基酸基础损失的估测方法,并对其在肉鸡饲料原料氨基酸营养价值评定中的应用作一总结。 相似文献
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本试验旨在使用线性回归法和差量法研究肉鸡饲粮钙磷比对豆粕中磷真消化率的影响。选用576只15日龄罗氏肉鸡,根据3×3因子完全随机区组设计分为9个处理,每个处理8个重复,每个重复8只鸡。通过添加3个水平的豆粕(30.00%、43.00%和56.00%),研究饲粮钙磷比(1.0、1.5和2.0)对豆粕中磷真消化率测定值的影响。试验期7 d。结果表明:肉鸡体增重、饲料转化效率、回肠食糜磷排泄量和可消化磷均随豆粕水平提高呈线性增加(P0.01),而干物质消化率和磷的表观消化率呈线性降低(P0.01)。提高饲粮钙磷比可显著增加回肠食糜磷排泄量,从而降低可消化磷和磷的表观消化率(P0.01)。使用线性回归法和差量法在钙磷比为2.0时测得豆粕中磷的真消化率分别为40.79%和39.84%,显著低于钙磷比在1.0(53.36%和55.59%)和1.5(56.81%和56.36%)时测得磷的真消化率(P0.05)。由此可见,肉鸡饲粮钙磷比显著影响豆粕中磷真消化率的测定,但真消化率计算方法(线性回归法和差量法)对测定结果无显著影响。 相似文献
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