首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 390 毫秒
1.
体外评定技术是利用离体方法评定反刍动物饲粮营养价值的一系列方法与技术。目前常用的体外评定技术包括瘤胃微生物消化法、酶法、尼龙袋法和体外产气法等。本文针对上述几种方法的特点及优缺点进行了评述,并详细介绍了体外产气技术,比较了注射器式和压力传感器式两个体外产气系统。  相似文献   

2.
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。  相似文献   

3.
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。  相似文献   

4.
利用体外产气法评定反刍动物饲料的营养价值   总被引:2,自引:0,他引:2  
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.  相似文献   

5.
体外产气法在动物营养学中应用的研究进展   总被引:1,自引:0,他引:1  
动物生产中饲料营养价值的高低直接影响动物的生产性能及畜产品的品质,实验室常用体外法来评价和估测饲料降解率。体外法主要通过测定底物如饲料降解后的残余量和发酵产物生成量(微生物数量、挥发性脂肪酸)或气体的产量来评价饲料营养价值。体外产气法是基于瘤胃发酵与产气高度相关的一种瘤胃体外模拟技术,该法具有简便、经济、快速、费用低等优点,目前在国内外多用于评价反刍动物饲草的饲用价值。作者主要综述了体外产气法在反刍动物生产中的应用及体外产气法中较为经典的发酵动力学模型。  相似文献   

6.
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。  相似文献   

7.
瘤胃发酵体外模拟方法及其应用   总被引:1,自引:0,他引:1  
瘤胃发酵体外模拟方法是利用离体方法研究瘤胃微生物营养与代谢以及评定反刍动物日粮营养价值的一类技术.目前常用的瘤胃发酵体外模拟方法主要包括两步法、体外产气和人工瘤胃持续动态发酵等方法.本文综述了这三种瘤胃发酵体外模拟方法的应用情况、存在问题及今后的发展趋势.  相似文献   

8.
奶牛饲料体外产气评定预测模型及其改进   总被引:1,自引:0,他引:1  
奶牛的生产性能很大程度上受制于饲料的营养价值。饲料营养价值评定需要测定其化学成分及消化特性,包括体内法(in vivo)、半体内法(in sire)和体外法(in vitro)。由于采用体内产气法可以测定发酵产物,考虑了饲料可溶但不发酵的部分,避免了消化道流量、指示剂、微生物指示剂和动物个体差异而导致的误差,同时具有估测动态发酵的优势,以其省时,省力,费用较低,成为评价反刍动物饲料营养价值的常用方法。饲料营养成分对体外评定法中体外消化率(IVTD)、产气量及挥发性脂肪酸产量的估测存在一定影响。  相似文献   

9.
反刍动物饲料营养价值评定包括饲料营养成分评定和饲料营养物质可利用性评定两个方面,其中,评定反刍动物饲料营养物质可利用性的方法主要有体内法、半体内法和体外法,因各自的特点分别应用于不同的研究领域.反刍动物饲料营养价值评定模型的应用,又使这些评定方法得到进一步深入和扩展.文章综述了反刍动物饲料营养价值评定的主要方法以及几种营养价值评定模型的应用研究进展.  相似文献   

10.
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。  相似文献   

11.
Background: The present work investigated the influence of lignin content and composition in the fungal treatment of lignocellulosic biomass in order to improve rumen degradability. Wheat straw and wood chips,differing in lignin composition, were treated with Lentinula edodes for 0, 2, 4, 8 and 12 wk and the changes occurring during fungal degradation were analyzed using pyrolysis-gas chromatography-mass spectrometry and detergent fiber analysis.Results: L. edodes preferentially degraded lignin, with only limited cellulose degradation, in wheat straw and wood chips, leaving a substrate enriched in cellulose. Syringyl(S)-lignin units were preferentially degraded than guaiacyl(G)-lignin units, resulting in a decreased S/G ratio. A decreasing S/G ratio(wheat straw: r =-0.72, wood chips: r =-0.75) and selective lignin degradation(wheat straw: r =-0.69, wood chips: r =-0.88) were correlated with in vitro gas production(IVGP), a good indicator for rumen degradability.Conclusions: L. edodes treatment increased the IVGP of wheat straw and wood chips. Effects on IVGP were similar for wheat straw and wood chips indicating that lignin content and 3D-structure of cell walls influence in vitro rumen degradability more than lignin composition.  相似文献   

12.
Wheat straw, sugarcane bagasse medium and konara oak logs used to cultivate edible basidiomycetes were treated with ammonium hydroxide to investigate the relationship between the degree of rotting and the effect of ammonium hydroxide treatment on digestibility. Wheat straw was sampled before inoculation and on days 67 and 97 after inoculation with Pleurotus salmoneostramineus. Similarly, bagasse media were sampled before inoculation and on days 47 and 96 after inoculation with Pleurotus abalonus. Konara oak logs were sampled before inoculation and at 2 and 4 years after inoculation with Lentinula edodes. Aliquots of the samples were treated with ammonium hydroxide (NH4‐N, 3% dry matter) at 45°C for 10 days. Ammonium hydroxide treatment increased the in vitro dry matter digestibility (IVDMD) and gas production (IVGP) of all the samples, except the konara oak samples collected before inoculation. The degree of increased digestibility was largest for the samples collected after short cultivation periods, followed by those collected after long cultivation periods and those collected before inoculation. However, the IVDMD and IVGP values after short cultivation periods were lower than those after long cultivation periods. Ammonium hydroxide treatment is effective at improving the digestibility of white‐rotted materials, although the effect is lessened as rotting proceeds.  相似文献   

13.
试验通过评定菜籽粕、玉米、米糠、苜蓿、玉米青贮和玉米秸秆的营养价值来比较瘤胃尼龙袋法和体外产气实验。结果表明:各种饲料的干物质有效降解率分别为52.90%、54.27%、65.70%、40.76%、37.24%和38.17%,精饲料干物质有效降解率(EDMD)中,a部分占比例较高(其中米糠达到64.51%);每克饲料DM的渐进产气量(A)分别为105.00、180.51、109.30、172.71、147.76和148.66 mL,粗饲料的产气量普遍高于精饲料;两种方法中,产气参数A、B与EDMD均呈负相关(r=-0.55和r=-0.61)。从速率曲线来看,降解速率曲线主要反映了b部分的降解情况,而饲料产气的速率曲线却能明显反映出两相的发酵情况。  相似文献   

14.
The capabilities of four white‐rot fungi to improve the digestibility of sugarcane bagasse for ruminants were determined. Bagasse was cultured with Lentinula edodes, Pleurotus eryngii, Pleurotus salmoneostramineus, Ceriporiopsis subvermispora (ATCC 90467) or C. subvermispora (CZ‐3) at 26°C for 8, 12 or 16 weeks. The in vitro organic matter digestibility (IVOMD) and in vitro neutral detergent fiber digestibility (IVNDFD) in untreated bagasse were 45.6 and 40.3%, respectively. Meanwhile, the bagasse cultured with L. edodes and two strains of C. subvermispora, respectively, for 12 weeks, were elevated to 68.6 and 59.1%, 60.6 and 49.9% and 59.9 and 49.0%, respectively. In contrast, the IVOMD and the IVNDFD in bagasse cultured with P. eryngii and P. salmoneostramineus were the same or lower than those in untreated bagasse. In vitro gas production (IVGP) in bagasse cultured with L. edodes and two strains of C. subvermispora for 12 weeks was also higher than that of untreated bagasse. These changes in IVOMD, IVNDFD and IVGP demonstrate that L. edodes has a higher capability of improving the digestibility for ruminants than C. subvermispora, P. eryngii or P. salmoneostramineus.  相似文献   

15.
Prediction of the supply of glycogenic precursors to dairy cows and the site of degradation of wheat, maize and potato starch (PS) were determined in an in vivo experiment and the results were compared with data obtained from experiments involving in situ nylon bag and in vitro gas production techniques. In a Latin square design experiment four lactating dairy cows fitted with a rumen cannula and T-piece cannulae in the duodenum and terminal ileum, received either a low-starch control diet or diets in which sugar beet pulp in the concentrate mixture had been replaced by wheat, maize or PS. Starch from the different sources was almost completely degraded in the total gastrointestinal tract. For all starches, the rumen was the main site of degradation in vivo. No digestion of PS in the small intestine was observed. In situ results suggested that 14% of wheat starch (WS), 47% of maize starch and 34% of PS escaped rumen fermentation. According to the gas production technique WS ferments quickest and potato slowest. PS had a low degradability during the first 8 (gas production) to 11 (in situ) h. However, according to both in vitro and in vivo measurements rumen degradability of PS was high. The results suggest that in situ and in vitro techniques should be performed in animals that have adapted to starch source to provide a more accurate simulation of the in vivo situation.  相似文献   

16.
Regarding the estimation of the energy concentration or digestibility of herb-dominated forage and plant samples from winter pastures, it could be expected that the estimation is only reliable when in vitro methods with rumen fluid as inoculum (= gas production techniques) are used. For the verification of this thesis based on logical reflections, an in vitro-method with rumen fluid added as inoculum, as well as chemical, and enzymatic methods were applied under consideration of existing estimating functions. As a possible reason for the observed divergence of the methods, effects of fungal infections or, respectively, secondary compounds in herbs are discussed. At the present state of knowledge, it is adequate to estimate the energy concentration in vitro by gas tests, as far as fattening types like suckler cows and beef cattle are concerned, maybe in contrast to the forage evaluation for dairy cows.  相似文献   

17.
The effects of yeast culture and fibrolytic enzyme preparation (containing cellulase and xylanase) on in vitro fermentation characteristics of rice straw, wheat straw, maize stover, and maize stover silage were examined using an in vitro gas production technique. Four levels of yeast culture and fibrolytic enzyme supplements (0, 2.5, 5.0, and 7.5 g/kg of straw DM, respectively) were tested in a 4 x 4 factorial arrangement. Supplementation of yeast culture increased the cumulative gas production, theoretical maximum of gas production, rate of gas production, IVDMD, and in vitro OM disappearance (IVOMD), and decreased the lag time for each type of straw. Fibrolytic enzyme supplementation tended to increase cumulative gas production, theoretical maximum of gas production, and rate of gas production; prolonged lag time of gas production; and enhanced IVDMD and IVOMD for 4 types of cereal straws, with the significance of this effect being dependent on the level of supplemented enzymes. There were significant interactions between fibrolytic enzymes and yeast on all in vitro gas production parameters, IVDMD, and IVOMD of each type of straw. The outcome of this research indicated that the application of fibrolytic enzyme preparation and yeast culture could improve in vitro gas production fermentation of cereal straws.  相似文献   

18.
本试验采用体外法研究无机磷对瘤胃发酵的影响。无机磷在培养液中设0、30、60、90、120、150、200、250、300、350 mg/L 10个水平。体外培养发酵48 h终止培养,测定培养液的产气量和干物质降解率。结果表明:无机磷添加水平对48 h总产气量和干物质降解率影响显著(P<0.05),随着无机磷添加水平的提高,48 h总产气量和干物质降解率显著提高(P<0.05),添加水平为200 mg/L时达到最大值,分别为44.30 mL和54.80%,随后下降。在本试验条件下,无机磷的适宜添加水平为200 mg/L。  相似文献   

19.
本文旨在利用体外产气法评定西藏地区不同牧草营养价值。选取西藏地区5种常见牧草,通过单因素试验设计,利用体外产气法评定5种牧草体外发酵48 h累积产气量、理论最大产气量(V_f)、初始产气速率(FRD_0)、达到最大产气量一半时所需时间(t_(0.5))、体外干物质消失率(IVDMD)、体外中性洗涤纤维消失率(IVNDFD)、p H、氨态氮(NH_3-N)浓度以及挥发性脂肪酸(VFA)产量。结果表明,体外发酵48 h后,苇状羊茅体外48 h累积产气量、V_f、FRD_0、IVDMD及甲烷(CH_4)、乙酸、丙酸、丁酸和总VFA产量均显著高于其他4种牧草(P0.05),但其体外发酵p H及乙酸/丙酸显著低于其他4种牧草(P0.05);紫花苜蓿体外NH_3-N浓度最高,显著高于其他4种牧草(P0.05)。综上分析,苇状羊茅体外发酵效果最佳,与其他试验牧草相比,更容易被瘤胃微生物降解利用。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号