评定猪饲料氨基酸营养价值的体外法

评定饲料氨基酸生物学效价的体外方法有化学方法、微生物方法、酶解方法和远红外反射光谱分析技术,本文对各种方法的优缺点作了分析和比较,从而为合理地评定猪饲料蛋白质氨基酸的营养价值提供了理论依据。     

体外法评定反刍动物饲料营养价值的研究进展

体外评定技术是用活体外测定方法评定反刍动物饲料营养价值的一系列方法与技术。可避免体内法的一些不足。体外评定法从20世纪50年代出现．主要有体外产气法、两步法;20世纪70年代发展起来的人工瘤胃持续发酵法;20世纪80年代末开始应用的近红外反射光谱技术．另外还有酶解法及溶解度法等。体外法与体内法、半体内法相比较,具有操作简便、容易标准化、结果重演性好等优点．从而得到了较广泛的应用。     

反刍家畜饲料营养价值体外法评定研究进展

本文综述了评价反刍家畜饲料营养价值的几种主要体外方法的最新研究进展,包括体外产气法、两步法、人工瘤胃持续发酵法、酶解法以及近红外反射光谱技术等。     

体外法评定反刍动物饲料营养价值的研究进展

本文综述了体外法评定反刍动物饲料营养价值的研究进展,主要有两步法,体外产气法,瘤胃持续模拟法,近红外反射光谱技术,酶解法和溶解度法。并比较了各种评价方法的优缺点。     

反刍动物饲料营养价值体外评定方法

介绍体外产气法、两步法(短期瘤胃法)、人工瘤胃持续发酵法(长期瘤胃法)、酶解法、溶解度法和近红外反射光谱技术(NIRS)等的基本原理、优缺点和应用情况。     

利用体外产气法评定反刍动物饲料的营养价值

本试验利用体外产气法评定反刍动物饲料的营养价值.对花生藤、木薯渣、柠檬酸渣和甜叶菊渣4种原料进行体外发酵试验.通过测定各种原料的24 h累计产气量、干物质(DM)降解率和细菌氮含量来评定其对反刍动物的营养价值.试验结果表明,2 g花生藤、木薯渣、柠檬酸渣和甜叶菊渣样品的24 h累计产气量分别为93.50、106.25、117.25 mL和54.33 mL;DM降解率分别为34.76%、48.34%、24.66%和33.63%;细菌氯含量分别为1.48、1.10、1.54mol/(g·mL)和1.59 mol/(g·mL).总体来看,这几种饲料可以作为反刍动物的新型饲料资源加以推广利用,而且用体外产气法评定反刍动物饲料的营养价值是可行的.     

评定反刍动物饲料营养价值的体外人工瘤胃法

配合反刍动物的平衡日粮依赖于组成日粮的各种饲料营养价值的准确评定。常规方法是用牛或羊进行消化、代谢和呼吸试验,这样测定一个样品需3～4周时间。采用体外人工瘤胃法评定饲料营养价值,可在较短的时间内测定大量样品,提供更多的有关饲料消化率和营养价值的重要数据。加拿大麦吉尔大学麦克摩纳农学院的反刍动物营养学教授依·多恩费(Donefer,E.)博士,于1961年制造了一套模仿     

利用体外产气法评定反刍动物饲料的营养价值

试验利用体外产气法评定反刍动物饲料的营养价值。对花生藤、木薯渣、柠檬酸渣和甜叶菊渣4种原料进行体外发酵试验,通过测定各种原料的24h累计产气量、干物质(DM)降解率和细菌氮含量来评定其对反刍动物的营养价值。试验结果表明:花生藤、木薯渣、柠檬酸渣和甜叶菊渣的24h累计产气量分别为93.50、106.25、117.25和54.33ml;DM降解率分别为34.76%、48.34%、24.66%和33.63%;细菌氮含量分别为1.48、1.10、1.54和1.59mol/(g·ml)。总体来看,这几种饲料可以作为反刍动物的新型饲料资源加以推广利用,而且用体外产气法评定反刍动物饲料的营养价值是可行的。     

体外产气法评定黔北麻羊常用饲料营养价值研究

试验以黔北麻羊为瘤胃液供体,以麦麸、DDGS、鱼粉、玉米皮、米糠、豆腐渣和青干草、麦冬草、黑麦草、高羊茅草为精粗饲料,应用瘤胃体外产气法检测累积产气量(GP)、发酵参数(a、b、c)和有机物消化率(OMD),评定其营养价值。结果表明,精饲料、粗饲料GP均随时间的延长而增加(P0.05)。至发酵72h结束,精饲料中GP、OMD值以玉米皮(63.89mL、64.70%)、麦麸(57.07mL、61.75%)、豆腐渣(56.36mL、60.01%)较高,具有较高的营养价值,DDGS(47.59mL、46.38%)次之,鱼粉(30.51mL、32.47%)、米糠(10.85mL、18.87%)相应较低(P0.05);粗饲料中GP、OMD值以黑麦草(44.31mL、49.63%)最高,营养价值最高;高羊茅草(37.01mL、41.32%)、青干草(34.21mL、40.97%)次之;麦冬草(28.82mL、35.08%)最低(P0.05)。精饲料中玉米皮、豆腐渣和麦麸营养价值较高,粗饲料中黑麦草营养价值较高。本研究结果可为黔北麻羊日粮配制提供参考。     

反刍动物饲料营养价值体外评定方法进展

此文论述了评价反刍动物饲料营养价值的几种主要体外方法，包括体外产气法、两步法（短期瘤胃法）、人工瘤胃持续发酵法（长期瘤胃法）、酶解法、溶解度法以及近红外反射光谱技术（NIRS）等。主要介绍了这几种方法的基本原理、优缺点、发展及应用情况。     

利用氨基酸指标评价鱼粉质量及掺假鉴别

鱼粉是一种重要的优质动物蛋白质原料,富含各种必需氨基酸,通过对鱼粉样品氨基酸数据的分析,总结出合格、低质、掺假鱼粉的氨基酸含量变化规律,提供了运用氨基酸指标评价鱼粉质量及掺假鉴别的方法。     

Nutritional evaluation of poultry by-product meal as a protein source for ruminants: small intestinal amino acid flow and disappearance in steers.

Six Angus steers (260+/-4 kg initial BW) fitted with ruminal, duodenal, and ileal cannulas were used in a 6 x 6 Latin square design to evaluate the effect of feeding poultry by-product meal (PBM) on small intestinal flow and disappearance of amino acids. The diets were provided at 2% of BW on a DM basis, formulated to contain 11.5% CP, and consisted of 49% corn silage, 36% cottonseed hulls, and 15% supplement on a DM basis. Supplements were formulated to contain 37% CP with sources of supplemental N being soybean meal (100% SBM) and 0, 25, 50, 75, and 100% PBM, with urea used to balance for N. Duodenal flow of all amino acids increased linearly (P < .07) as PBM increased in the diet and, except for His, increased (P < .09) for 100% PBM compared with 100% SBM. Similar results were observed for duodenal flow of nonbacterial amino acids, which linearly increased (P < .05) with PBM and were greater (P < .05) for 100% PBM than for 100% SBM. Soybean meal increased (P < .09) the duodenal flow of nonbacterial Lys compared with 0% PBM, and 0% PBM increased (P < .04) flow of Val, Ala, and Pro compared with 100% SBM. Duodenal bacterial essential, nonessential, and total amino acid flows were not affected (P > .80) by PBM; however, they were greater (P < .02) for 100% SBM than for 100% PBM. In addition, nonessential and total bacterial amino acid flows were increased (P < .06) for 100% SBM compared with 0% PBM. Small intestinal disappearance of Lys and Pro increased linearly (P < .09) as PBM increased, and 100% PBM increased (P < .07) disappearance of Arg and Ala compared with 100% SBM. Supplemental N source had no effect (P > .31) on apparent small intestinal disappearance of essential, nonessential, and total amino acids. These data suggest that when PBM, SBM, and urea were used as sources of supplemental N, the daily disappearance of amino acids from the small intestine of steer calves consuming a corn silage- and cottonseed hull-based diet was similar.     

Production of aromatic amino acids and related compounds from p-hydroxyphenylacetic acid by rumen microorganisms in vitro

Suspensions of mixed rumen bacteria (B), protozoa (P), and mixed rumen microorganisms (BP) prepared from rumen contents of fistulated goats were anaerobically incubated with 1 mM p‐hydroxyphenylacetic acid (HPA) at 39°C for 24 h. Tyrosine (Tyr), phenylalanine (Phe), tryptophan (Trp) and other related compounds in both supernatants and hydrolyzates of microbial cells in all incubations were analyzed by HPLC. Large amounts of Tyr (32.1, 42.7 and 36.1% of disappeared HPA in B, P and BP, respectively) were produced from HPA during a 12 h incubation period. The formation of Tyr in P (178.6 µmol/g MN) was 1.5 and 2 times higher than in B and BP, respectively. Phe (7–11% of the disappeared HPA) and Trp (3–6% of the disappeared HPA) were also synthesized from HPA in B, P, and BP. Phe synthesis in P (46.3 µmol/g MN) was 1.7 times higher than in B but, in contrast, Trp synthesis in B, was 1.6 times higher than in P. The metabolites p‐hydroxyphenylpyruvic acid (in the range of 5–14% of disappeared HPA), phenylacetic acid (1–11%), p‐hydroxybenzoic acid (3–7%) and benzoic acid (1–6%) were produced from HPA in B, P and BP. Phenylpropionic acid (6% of the disappeared HPA) was produced only in B and BP.     

CNCPS氨基酸模型评定奶牛氨基酸供给和需求

1　氨基酸供应量奶牛可吸收且最终能够利用的氨基酸是由瘤胃微生物合成的蛋白、日粮过瘤胃蛋白和分泌到消化道中的内源性蛋白来提供 (Richardson和Hatfield ,1978)。以Russell等 (1992 )和Sniffen等 (1992 )的模型作为基础而得出氨基酸供应模型 ,用其模型可估计由瘤胃微生物合成的蛋白和由日粮过瘤胃蛋白提供的氨基酸量。由于描述奶牛内源性分泌的氨基酸数量资料有限 ,模型不考虑由内源性分泌蛋白提供的氨基酸量 (Mantysaari等 ,1989)。因此 ,在模型中 ,依据由瘤胃微生物蛋白和日粮过瘤胃蛋白而得到的氨基酸量 ,来确定由特定日粮而获得的…     

龙须眼子菜营养价值评定

龙须眼子菜是多年生草本植物,可作为鱼、鸭饲料,还可入药,具有清热解毒功效。内蒙古自治区境内的内陆湖泊乌梁素海,总面积为29300hm2。近年来,由于携带大量化肥和富含氮磷营养盐的农田退水入湖,在充足的水分和光照条件下,大型水生植物生长茂盛,充塞整个水体空间,形成典型的富营养化草型湖泊。沉水植物中龙须眼子菜占到95%以上。每年可收获龙须眼子菜干草5万t,使利用沉水植物规模化生产草粉饲料成为可能。本试验对不同月份生长和经过脱灰处理的水草进行了全面营养分析及比较,为开发新的水生饲料资源提供营养技术参数。1材料与方法1.1材料内蒙…     

Nutritional evaluation of the legume Macrotyloma axillare using in vitro and in vivo bioassays in sheep

This study consisted of two experiments with the following objectives: to evaluate the effects of tannins from the tropical legume macrotiloma (Macrotyloma axillare) on total gas and methane (CH₄) production, as well as on ruminal fermentation parameters by performing an in vitro bioassay, with samples incubated with and without polyethylene glycol (PEG) in a semi‐automatic system; and secondly in a 17 day in vivo experiment, to determine apparent total tract digestibility (ATTD) of dietary nutrients and ruminal fermentation parameters of 12 intact 8‐ to 9‐month‐old Santa Inês (averaging 24.95 ± 1.8 kg body weight) ewes fed tropical grass hay supplemented with macrotiloma hay. The ewes were divided into two treatment groups depending on their diet: chopped aruana grass hay (Panicum maximum cv. Aruana) (control—CON); and aruana grass hay supplemented with chopped macrotiloma hay (macrotiloma—MAC). The animals were kept for 5 consecutive days in metabolic cages for the ATTD assay, and at the end of this period, samples of rumen fluid were collected from each ewe to determine ammoniacal nitrogen (NH₃‐N) and short‐chain fatty acid (SCFA) production, and protozoa count. For the in vitro assay, a decrease in total gas and CH₄ production was observed for samples incubated without PEG (p < .05). No differences were observed for the other parameters evaluated (p > .05). In the in vivo experiment, increased intake and ATTD of crude protein were observed for the animals fed MAC when compared to CON (p < .05). For rumen fermentation parameters, increased NH₃‐N, total SCFA and isobutyrate concentrations, as well as reduced protozoa count were observed for MAC when compared to CON (p < .05). The results observed here indicated the potential of macrotiloma for use as a ruminant feed, and antimethanogenic potential of this plant was noted.     

体外法评价张杂谷秸秆、全株青贮张杂谷和燕麦草的营养价值

试验旨在通过体外产气法评价张杂谷秸秆、全株青贮张杂谷和燕麦草的营养价值。采用单因素试验设计,将1 g张杂谷秸秆、全株青贮张杂谷和燕麦草分别进行体外发酵,每组设4个重复,测定和分析三种粗饲料对体外产气量、挥发性脂肪酸、营养物质降解率、pH值、微生物蛋白、氨态氮的影响。结果表明,张杂谷秸秆、全株青贮张杂谷4、8、16、24、36、48、72 h的产气量及理论最大产气量(B)均极显著小于燕麦草的(P<0.01),全株青贮张杂谷8、16、24、36、72 h的产气量极显著大于张杂谷秸秆(P<0.01);产气速率(c)和延搁时间(Lag)张杂谷秸秆和燕麦草的差异均不显著(P>0.05),极显著低于全株青贮张杂谷(P<0.01)。体外发酵72 h后,乙酸、丁酸、总挥发性脂肪酸浓度均是张杂谷秸秆产生的极显著低于全株青贮张杂谷、燕麦草的(P<0.01);丙酸、乙酸/丙酸浓度张杂谷秸秆极显著低于全株青贮张杂谷(P<0.01),全株青贮张杂谷极显著低于燕麦草(P<0.01)。干物质、粗蛋白质、中性洗涤纤维和酸性洗涤纤维降解率均表现出张杂谷秸秆极显著低于全株青贮张杂谷(P<0.01),全株青贮张杂谷极显著低于燕麦草(P<0.01);pH值变化为张杂谷秸秆、全株青贮张杂谷极显著高于燕麦草(P<0.01);微生物蛋白质产量三者差异均不显著(P>0.05),NH3-N浓度为张杂谷秸秆显著低于全株青贮张杂谷(P<0.05),两者与燕麦草差异不显著(P>0.05)。因此,该试验条件下,张杂谷秸秆、全株青贮张杂谷体外发酵在产气量、营养物质降解率方面相对次于燕麦草,全株青贮张杂谷相对优于张杂谷秸秆,具体原因及实际饲喂应用效果有待研究。     

合作猪肌肉氨基酸含量测定及营养价值评价

采用氨基酸自动分析仪测定不同月龄合作猪及对照组八眉猪肌肉氨基酸含量,并通过考察蒸煮处理对氨基酸含量水平的影响,评价合作猪肌肉营养价值。结果表明,合作猪肌肉氨基酸含量高于FAO/WHO的模式标准,可以判断合作猪肉是优质蛋白质来源。蒸煮后,合作猪肌肉中总氨基酸、必需氨基酸、非必需氨基酸以及鲜味氨基酸含量均有所下降,但EAA/TAA、EAA/NEAA上升。多数氨基酸含量在蒸煮后下降,降幅7.61%~78.39%,但丙氨酸、缬氨酸、组氨酸含量有所增加。     

动物营养代谢中的酸碱平衡

动物维持正常的酸碱平衡,是发挥机体细胞整体功能效应的必要前提。当某种酶活性对微小ｐＨ值变化敏感时,许多中间代谢产物反应,调控着动物细胞酸碱平衡。酸碱平衡是氢离子浓度的一种功能。当难于测定细胞内液和亚细胞内ｐＨ变化时,一般测定细胞外液中氢离子浓度,大多数哺乳动物细胞外液氢离子浓度维持在低水平状态(40×10-9ｍｏｌ/Ｌ或40ｎＥｑ/Ｌ,ｐＨ74)。细胞内液氢离子浓度比细胞外液高,哺乳动物肌肉细胞胞液ｐＨ值67～71变化,这种差异是维持细胞内代谢产物浓度的重要因子。但在细胞内,亚细胞器与胞液间也存在氢离子浓度差异。线粒体内…