以NDF估测奶牛进食量及生产性能优于ADF

麦迪逊大学最近研究表明:中性洗涤纤维(NDF)含量比之酸性洗涤纤维(ADF)含量能更好地预测采食量和产奶成绩。Satter 等发现:即便是同一种饲草源,牛奶产量与日粮中 NDF 含量较之 ADF 含量存在着更强的相关。NDF 测定植物总的细胞壁成分:纤维素和半纤维素以及木质素。ADF 测定纤维素和木质素,但不测半纤维素。以 Combs的观点,就意味着测定 ADF 遗漏了植物可消化纤维的一个较重要的部分。半纤维素含量在各种植物间差异很大,特别是在禾本科植物与豆科植物之间。即使一种禾本科植物与一种豆种植物的 ADF 含量相等,禾本科植物含有更     

辽宁绒山羊常用饲料营养价值评定

采集辽宁绒山羊常用饲料17种23个样品,应用康奈尔净碳水化合物-蛋白体系(CNCPS)提出的原理和方法对饲料营养价值进行评价。测定饲料原料常规营养成分以及非蛋白氮(NPN)、可溶性蛋白(SCP)、酸性洗涤不溶蛋白(ADFIP)、中性洗涤不溶蛋白(NDFIP)及酸性洗涤纤维(ADF)、中性洗涤纤维(NDF)、木质素(LIGNIN)和淀粉,并对饲料原料的蛋白质和碳水化合物进行分类分析。结果表明:粗饲料可溶性蛋白质主要是NPN,真蛋白含量少,3种蛋白质饲料可溶蛋白主要是真蛋白,NPN含量少;所采集灌木类饲料纤维含量尤其是慢速降解细胞壁成分含量低,可快速降解糖类和可利用蛋白质含量高,质量优于秸秆和干草等其他粗饲料;棉粕的不可消化纤维和不可消化蛋白质含量高,可消化利用性较差。豆皮的蛋白质含量较低,主要是慢速降解纤维成分占绝大多数。     

饲料粗纤维、中性洗涤纤维和酸性洗涤纤维残渣中各成分的研究

本试验旨在研究饲料粗纤维、中性洗涤纤维和酸性洗涤纤维残渣中各成分。试验采用聚酯纤维筛网袋法测定了米糠、小麦麸、白三叶、枸树叶、全株玉米、全株小麦、毛苕子、兔配合饲料、高粱、燕麦秸、苜蓿、稻秸、小黑麦干草、皇竹草、芦苇、花生秧、大豆秸和稻壳粉18种饲料的粗纤维(CF)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量,测定了饲料CF残渣中半纤维素、纤维素、酸性洗涤木质素和酸不溶灰分的含量及回收率,同时测定了NDF和ADF残渣中半纤维素、纤维素、酸性洗涤木质素和酸不溶灰分的含量,研究了饲料中的CF、NDF和ADF残渣中各成分含量及CF和ADF之间的相互关系。结果表明:所测18种饲料中的纤维素在CF残渣中的回收率最高(71.28%~105.03%);饲料ADF含量(y_1)和CF含量(x_1)之间呈高度正相关:y_1=1.507 1+1.211 5x_1(r=0.979 2,RSD=1.863 4,P0.01);饲料ADF残渣中去除酸不溶灰分后的ADF含量(y_2)和CF含量(x_2)之间的相关性更高:y_2=2.406 3+1.077 0x_2(r=0.990 5,RSD=0.962 4,P0.01)。由此提出饲料中半纤维素和纤维素含量的准确测定计算方法,即半纤维素含量等于NDF含量(无酸不溶灰分)减去ADF含量(无酸不溶灰分);纤维素含量等于ADF含量(无酸不溶灰分)减去酸性洗涤木质素含量。     

阿拉伯木聚糖作为大米副产物中主要的非淀粉多糖对其消化率的影响

文章旨在研究糙米、碎米、米糠、米糠粕和统糠中碳水化合物的组成及体外干物质消化率和体外有机物消化率,同时评估大米副产品干物质和有机物体外消化率与碳水化合物成分中纤维含量的相关性。试验分析了碎米、糙米、米糠、米糠粕和统糠的总能、干物质、灰分、中性洗涤纤维、酸性洗涤纤维、酸性洗涤木质素、粗蛋白质以及粗脂肪含量,同时分析了5种大米副产物的淀粉含量,并以非淀粉多糖、纤维素、可溶、不溶性非纤维素多糖以及木质素为指标对其纤维浓度进行定量。结果显示:米糠总能和粗脂肪含量最高(P<0.05),碎米和糙米中性洗涤纤维、酸性洗涤纤维、酸性洗涤木质素和灰分含量显著低于米糠、米糠粕和统糠(P<0.05)。统糠中性洗涤纤维、酸性洗涤纤维、酸性洗涤木质素和灰分含量最高(P<0.05),而粗蛋白质含量最低(P<0.05)。碎米和糙米淀粉含量大于80%,米糠和米糠粕淀粉含量低于27%,统糠淀粉含量最低,但粗纤维含量最高。米糠粕中阿拉伯糖和糖醛酸含量高于其他大米副产物,而统糠木糖含量最高,米糠中木糖的含量只有0.01%。碎米和糙米干物质和有机物体外消化率均显著高于其他大米副产物(P<0.05),干物质和有机物体外消化率与中性洗涤纤维、酸性洗涤纤维、酸性洗涤木质素、不溶性非纤维多糖、纤维素、非淀粉多糖、可溶性纤维、不溶性纤维和粗纤维含量均表现为显著负相关效应(P<0.05)。结论:除了统糠主要以纤维素为主要组分外,其他大米副产物的多糖成分主要是阿拉伯木聚糖。随着纤维含量的增加,大米副产物干物质和有机物体外消化率不断降低。     

饲料中的粗纤维、NDF、ADF和ADL含量的快速测定方法

<正>本文介绍了用聚酯纤维滤网袋法测定饲料中的粗纤维、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)和木质素(ADL)含量的快速测定方法。聚酯纤维滤网袋法具有简单、方便、快速和准确度的特点,可以进行纤维成分的批量快速测定。饲料中的粗纤维(CF)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)和木质素(ADL)是粗饲料、糠麸类、杂粕类等饲料中碳水化合物的主要成分,主要由半纤维素、纤维素、木质素等。到目前为止,国家颁布了国家标准饲料中粗纤维的含量测定(过滤法GB/6434-2006/ISO6865:2000);国家标准饲料中中性洗涤纤维(NDF)的测定     

燕麦饲草多组分营养差异分析

为挖掘利用高营养燕麦饲草种质资源,将源自以色列不同地区的23份野生燕麦生态型和3份燕麦栽培品种种植于四川甘孜、贵州贵阳、四川成都3个环境,分别在抽穗期、灌浆期、成熟期进行刈割处理,并测定其酸性洗涤纤维(ADF)、中性洗涤纤维(NDF)、酸性洗涤木质素(ADL)、纤维素(F)、半纤维素(HF)、木质素(L)、洗涤纤维中性...     

纤维性物质分析方法的演变

纤维性物质(主要包括纤维素、半纤维素和木质素)的准确定量,是正确评定饲料营养价值和科学饲养所必需。纤维性物质的分析方法,是随科学技术与分析手段的不断进步而逐渐改进和完善的。它经历了传统的粗纤维分析法、范氏和冯氏的中性洗涤纤维(NOF)与酸性洗涤纤维(ADF)分析法、和阿氏的高消化纤维(O_a)和低消化纤维(O_b)分析法的发展过程。本文就各种分析法的原理和主要优缺点作一简要介绍。     

不同方法测定反刍动物饲料NDF、ADF和木质素含量的比较

采用传统抽滤、ANKOM滤袋和CAU滤袋技术测定16种反刍动物饲料的中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)和木质素(PL,高锰酸钾法)含量。结果表明:3种方法测定的大部分饲料的NDF、ADF和PL含量间没有差异(P>0.05),但在测定谷物性饲料NDF含量时,ANKOM滤袋技术测定值明显低于其他2种方法(P<0.05);在测定动物性蛋白质饲料时,CAU滤袋测定的NDF值明显高于其他2种方法(P<0.05)。3种方法测定的NDF、ADF和木质素含量均具有显著的线性相关关系(R2=0.990～0.996),其中2个滤袋技术测定值之间的相关程度最高(R2=0.992～0.996);2个滤袋技术测定值的变异系数(CV=2.20%～3.96%)均小于传统抽滤(CV=3.21%～4.91%)。     

几种处理对柠条养分的影响及其在瘤胃内的降解

用3头瘘管羊,以尼龙袋法(in situ)测定黄贮柠条Caragana microphylla、氨化柠条、生化处理柠条等在瘤胃发酵6,12,24,36,48和72 h后粗蛋白(CP)、酸性洗涤纤维(ADF)、中性洗涤纤维(NDF)、酸性洗涤木质素(ADL)的降解率。结果表明,与对照组相比,处理柠条CP含量都上升(P<0.05),其中氨化柠条粗蛋白上升最高,NDF、ADF和ADL含量却都有所下降;柠条以尼龙袋法在瘤胃内降解48 h后,氨化处理柠条各营养物质降解效果都表现出最好,CP降解率为56.62%,NDF降解率为47.03%,ADF降解率为37.08%,NDL降解率为35.58%,与其它各组相比,差异显著(P<0.05)。     

汽爆加工与碱化贮存提高沙棘枝干的饲用价值

为了研究汽爆加工和氧化钙添加贮存对沙棘枝干的饲用价值的影响，将沙棘枝干汽爆加工（1.5 MPa、20 min）后进行氧化钙（0、2%、4%）碱化贮存。结果显示：汽爆加工使沙棘枝干中性洗涤纤维（NDF）、半纤维素、纤维素含量显著减少（P<0.05），而酸性洗涤纤维（ADF）、酸性洗涤木质素（ADL）、可溶性糖及瘤胃丙酸含量显著增加（P<0.05），氧化钙碱贮使NDF、ADF、ADL、半纤维素和纤维素含量减少，而可溶性糖、灰分及瘤胃乙酸含量显著增加（P<0.05）；汽爆加工使代谢能预测值升高而氧化钙碱贮使其显著降低（P<0.05）。汽爆加工提高了沙棘枝干的饲用价值而氧化钙碱贮作用有待进一步研究。     

利用饲料原料中的营养成分和可消化营养成分含量建立肉羊常用蛋白质饲料原料代谢能的预测模型

本试验应用套算法分析肉羊常用蛋白质饲料原料中的营养成分含量和可消化营养成分对有效能值的影响,基于饲料原料中的营养成分含量和可消化营养成分建立蛋白质饲料原料代谢能(ME)的预测模型。选取36只22月龄、体重为(52.6±1.4)kg的杜泊×小尾寒羊F1代杂交去势肉羊,采用完全随机区组设计分为6个处理,包括1个基础饲粮处理和5个试验饲粮处理,每个处理6只羊。利用消化代谢试验和呼吸代谢试验并结合套算法计算5种蛋白质饲料原料的消化能(DE)和ME,并分析蛋白质饲料原料DE、ME与该原料中营养成分[干物质(DM)、有机物(OM)、总能(GE)、粗蛋白质(CP)、粗脂肪(EE)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)]和可消化营养成分[可消化干物质(DDM)、可消化有机物(DOM)、可消化粗蛋白质(DCP)、可消化粗脂肪(DEE)、可消化中性洗涤纤维(DNDF)、可消化酸性洗涤纤维(DADF)]含量之间的相关关系。结果表明:饲料原料中的OM、DDM、DOM、DCP含量与DE和ME均存在极显著正相关(P0.01);另外,DADF与DE存在极显著负相关(P0.01),与ME存在显著负相关(P0.05)。通过饲料原料中的营养成分含量预测ME的方程为:ME(MJ/kg)=-82.855+2.391OM(%)+1.802EE(%)-6.21GE(MJ/kg)-0.121ADF(%)(R2=0.910,n=30,P0.01);通过饲料原料中的可消化营养成分含量预测ME的方程为:ME(MJ/kg)=-5.564+30.526DOM(%)+55.402DEE(%)(R2=0.841,n=30,P0.01);通过饲料原料中的可消化营养成分含量与DE共同预测ME的方程为:ME=-5.787+1.126DE(MJ/kg)+20.769DEE(%)(R2=0.879,n=30,P0.01)。综上所述,在本试验中,蛋白质饲料原料中的部分营养成分和可消化营养成分含量与ME之间存在显著相关,可通过饲料原料中的营养成分和可消化营养成分含量对肉羊蛋白质饲料原料的ME进行有效预测。     

Estimation of nutritive value and dry matter intake of forage

Since the 1900s, proximate analysis has been the mainstream method of feed analysis. In addition to this method, the detergent method, which was developed in the 1960s, has become a popular methodology for feed composition and nutritive value evaluation. One fundamental characteristic of this method is that fractionated carbohydrates are classified as either the fiber of feed in terms of neutral detergent fiber (NDF) or non‐fiber carbohydrates (NFC), which include sugar and starch. Meanwhile, in Japan another method, the enzymatic method, has been developed. The characteristic of this method is that fractionated carbohydrates are classified as either the fiber contained in feed in terms of organic cell wall (OCW) or nitrogen‐cell wall free extracts (NCWFE, non‐structural carbohydrates). One important fraction of feed nutrition is digestible carbohydrates, which are the sum of digestible non‐structural carbohydrates and the digestible fiber. The content of digestible non‐structural carbohydrates is obtained based on the nutritional uniformity of NFC and NCWFE in the detergent and enzymatic method, individually. The digestible fiber is obtained in the detergent method from the potential digestibility of NDF and lignifications, and obtained in the enzymatic method from the highly digestible organic a fraction and the poorly digestible organic b (Ob) fraction. The amount of digestible carbohydrates obtained by these two methods of analysis is sometimes significantly different. The Ob fraction obtained by the enzymatic method shows a significant negative correlation, and a 1% increase in the Ob content of hay dry matter suppresses the dry matter intake of dairy cattle by 0.17 kg.     

反刍动物日粮物理有效中性洗涤纤维的研究进展

饲料纤维在反刍动物日粮中不仅具有化学成分的重要性,且纤维的物理性状(颗粒大小)还能够影响咀嚼活动、瘤胃发酵、乳脂肪含量及机体健康状况。作者就表征纤维的化学和物理性状的指标——物理有效中性洗涤纤维的定义、内涵、计算方法及对反刍动物进食行为、瘤胃发酵、营养物质消化率和泌乳性能等方面的营养调控功能进行了综述。     

Determination of feeding value based on simple food characteristics. 1. Determination of the digestibility of green foods and their preservation products]

Regression techniques may be used to establish close relations between the crude fibre content and digestibility data of organic materials (total digestibility). It was shown from regression equations calculated for a number of feedingstuffs that the total digestibility of a feedstuff may be calculated, with a sufficient degree of accuracy, from the crude fibre content of the material. The range of variations from most of the digestibility data obtained for various feedstuffs, was clearly below the limit given (2.5%). When regression equations are used the variation limits should always be indicated for which they had been established. Differences within the different groups of feedstuffs are so small that in many instances, the same equation may generally be used for feedstuffs of the same group. Similarly, equations for calculating digestibility values may be derived on the basis of the lignin content of a material, although the range of variations will, in this case, be wider when compared with the crude fibre content. The reason for this must be seen in the greater uncertainty of the lignin method. Analogous regression equations may be found for the different conserving products of green feeds, in which certain alterations have to be made corresponding to the different methods of conserving used. On the one hand, these are accounted for by changes in the crude fibre content brought about by biochemical reactions during the conserving process on the other hand a special influence of conserving form can be observed. The content of digestible crude protein in green feeds can be established, with a high degree of accuracy, from the crude protein content of the material. The content of digestible organic matter can be calculated from the digestibility of organic matter and from the ash content of the material. The content of digestible organic matter is, in turn, closely related to the content of energetic feed units in a particular material.     

Digestibility of amino acids in swine: Results and their practical applications. A review

Many studies have been carried out on the topic of amino acid digestibility in swine during the last two decades. The ileal analysis method should be the method of choice for determining amino acid digestibilities. This method is very sensitive for detecting differences in amino acid digestibilities, as these result from processing conditions or from inherent differences between samples of the same feedstuff. Amino acid digestibility values from the literature, determined with the ileal analysis method, are summarized and show large differences in amino acid digestibilities between feedstuffs and among different samples of the same feedstuff. At present it seems most appropriate to relate to amino acid digestibilities in terms of their apparent values. Studies in which the ¹⁵N isotope dilution technique was used to determine the endogenous amino acid losses have shown that the traditional methods for determining the endogenous amino acid losses should be re-evaluated. Recent studies have clearly shown improvements in diet formulation practices, especially when a good quality protein supplement is replaced by protein supplement(s) of lower quality combined with supplementary amino acids, and when diets are formulated on the basis of digestible rather than total supply of the limiting amino acid(s). In addition, in order to present improved values for amino acid requirements, these should be expressed as digestible rather than as total.     

Digestibility and absorption of nutrients as affected by fibre content in the diet of the pig. Quantitative aspects

An attempt has been made to assess some quantitative aspects of the influence of fibre content in feedstuffs and diets on the digestibility and absorption of nutrients in pigs. The study is based on selected published literature and data from Danish experiments.The digestibility of nutrients consistently decreases with increasing fibre content in the diet, regardless of the analytical method used. However, the magnitude of this negative influence depends on the type and origin of the fibre source, technical treatment, feeding level, age and live weight of the pigs, etc.Increasing the content of crude fibre in diets is related to increasing the content of less digestible carbohydrate (hemicellulose) and a concurrent decrease in the content of easily digestible substances. It is shown that for each 1% increase in the crude fibre content, the content of starch + sugars in the NFE-fraction is decreased by 2.1–2.7%. This results in a reduced ileal digestibility, enhanced fermentation in the hindgut and an overall reduction of the digestibility of gross energy.Experimental data from this institute comprising 246 diets and 257 single feedstuffs were used to generate equations for prediction of the digestibility of gross energy. A single carbohydrate fraction (NDF or crude fibre) alone accounted for about 70% of the variation in digestibility in diets and 85% of the variation in digestibility of single feedstuffs.Fibre determination values based on either detergent methods (NDF) or crude fibre analysis supplemented with enzymic determination of starch + sugars were equally good as predictors of the digestibility of gross energy.     

应用套算法估测肉羊精饲料代谢能

本试验旨在应用套算法建立肉羊精饲料代谢能估测模型。选取66只18月龄体重为(49.6±1.3)kg的杜泊×小尾寒羊F1代去势肉羊,采用完全随机区组设计分为11组,包括1个基础饲粮组和10个试验饲粮组,每组6只羊。通过消化代谢试验(为期8 d)和气体代谢试验(为期3 d)并结合套算法计算10种精饲料的消化能和代谢能,建立精饲料代谢能和其概略养分或可消化养分之间的模型。结果表明,1)10种精饲料总能、酸性洗涤纤维含量与消化能呈显著相关(P0.05),有机物含量与消化能达到极显著相关(P0.01);精饲料概略养分与代谢能之间则无显著相关性(P0.05)。2)10种精饲料的可消化养分与代谢能存在极显著相关(P0.01),所建立的预测方程为:ME=-1.907+1.344DE+1.321DDM-5.347DOM-2.093DADF(R2=0.845,n=60,P0.01);ME=-2.105+1.349DE-6.577DOM(R2=0.842,n=60,P0.01)。[ME为代谢能(MJ/kg),DE为消化能(MJ/kg),DDM为可消化干物质(%),DOM为可消化有机物(%),DA DF为可消化酸性洗涤纤维(%)。]综上所述,本试验条件下无法利用精饲料概略养分预测其代谢能,通过精饲料的可消化养分可准确预测其代谢能。     

单胃动物饲料消化能评定方法剖析

从单胃动物消化能评定方法的研究进展入手,详细综述了评定饲料消化能的各种非生物学方法,并对这些方法的实际应用效果和应用价值进行了评价。同时,对各种方法所存在的问题进行了剖析,从生物学和营养学的角度探讨了非生物学法评定饲料消化能值的可行性。     

Postprandial trends in estimated ruminal digesta polysaccharides and their relation to changes in bacterial groups and ruminal fluid characteristics

In a diurnal study, feedstuff and digesta polysaccharides, ruminal bacterial carbohydrate-fermenting groups, and selected ruminal fluid characteristics (ruminal pH, ammonia and volatile fatty acids) were measured in ruminal-cannulated Holstein steers fed high- or low-forage diets at maintenance level intake once daily. A procedure for the sequential extraction of soluble sugar, starch, pectin, hemicellulose and cellulose from feedstuffs was developed to measure these carbohydrates in dietary and ruminal digesta samples. Recovery of dry matter (determined chemically) using this scheme was 60 to 70%. Data were obtained within the ranges of those in the literature for similar feedstuffs and(or) by similar methods. Dietary analysis by the sequential method yielded total recovery across all carbohydrate fractions of 87 and 81% for the high- and low-forage diets, respectively, and similar recoveries were obtained for the digesta samples. Analytical variation was small (less than or equal to 15% CV), which permitted comparison of the carbohydrate profiles of the digesta over time. From these values, total ruminal digesta polysaccharide content was calculated and, when plotted over time, indicated that the disappearance per fraction corresponded with theoretical curves for ruminal fermentation of major feedstuff components. The postprandial variation within the bacterial population carbohydrate-fermenting groups was small, but changes were consistent with digesta component fermentation. Xylan- and cellulose-fermenting groups followed a pattern compatible with the disappearance of these polysaccharides from the rumen. In contrast, soluble sugar-fermenting groups predominated at all times despite the rapid rise and fall of these components in the digesta. Ruminal fluid pH, ammonia and total carbohydrate supported the digesta and bacterial trends observed. The data are interpreted to suggest that once daily maintenance feeding of high- or low- forage diets permits detection of digesta sugar and polysaccharide changes, supports a relatively stable microbial population while specific groups increase and decrease with the availability of substrate, and results in few differences in ruminal fluid traits.     

Comparison of the dietary fiber digestibility and fermentability of feedstuffs determined by conventional methods and in vitro gas production technique in pigs

Abstract

This study evaluated the accuracy of an in vitro 2-step method combined with an in vitro gas production technique (2+IVGPT) for the estimation of dietary fiber (DF) digestibility coefficient and fermentability of feedstuffs in the large intestine of growing pigs. Digestibility coefficients of corn, wheat, soybean meal, and wheat bran, estimated by the in vitro methods, including the 2-step, 3-step, 2+IVGPT, and in vivo were compared. The fermentation characteristics of feedstuffs were also determined through the 2+IVGPT. The results showed that the in vivo DF digestibility coefficient of wheat bran was 0.39, which was similar to the result estimated by the 2+IVGPT (0.40). In regard to the fermentation characteristics, the lowest maximum rate of gas production (R_max) was obtained for wheat bran (11.0 ml h^?1). To conclude, in vivo total tract digestibility of DF in the fibrous feedstuff (e.g. wheat bran) could be accurately estimated by the 2+IVGPT.