日粮中添加硫酸钠对陕北白绒山羊瘤胃纤维素降解率的影响

【目的】研究含不同水平硫酸钠日粮对陕北白绒山羊瘤胃纤维素降解率的影响,为选择适宜的硫添加水平提供理论依据。【方法】选择4只健康、体质量(28~32 kg)相近且安装永久性瘤胃瘘管的陕北白绒山羊为试验动物,采用4×4拉丁方单因素试验设计,试验分4个时期进行,每个时期14 d,分别饲喂硫酸钠添加水平为0(对照组),2.0,4.8,6.4 g/kg的4种日粮,测定瘤胃内青贮饲料干物质(DM)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)的动态降解率,计算青贮饲料瘤胃DM、NDF、ADF的有效降解率(PED),并进行显著性检验。【结果】与对照组相比,日粮中添加硫酸钠对瘤胃食糜外流速率(Kp)无显著影响;提高了瘤胃内青贮饲料DM、NDF、ADF的PED值,而且当硫酸钠添加水平分别为4.8和6.4 g/kg时,PED值有显著或极显著提高。【结论】日粮中添加硫酸钠可以提高陕北白绒山羊非产绒期瘤胃内粗饲料纤维的PED值,且PED值随着硫酸钠添加水平的增加而增大,当硫酸钠水平为6.4 g/kg时,青贮玉米PED值最大,从而使青贮玉米得到了更好的利用。     

烟草和水稻中水稻条斑病菌过敏反应激发子Ssb_x互作因子的鉴定

【目的】水稻条斑病菌(Xanthomonas oryzae pv.oryzicola)中单链DNA结合蛋白(single-stranded DNA-binding protein,SsbX)通过病原菌III型分泌系统(type-III secretion system,T3SS)分泌,在非寄主植物烟草上产生过敏反应(hypersensitive response,HR),研究旨在明确SsbX激发烟草产生HR的机理。【方法】将水稻条斑病菌RS105菌株注射水稻和烟草叶片,应用CreatorTM SMARTTM cDNA文库构建试剂盒构建水稻和烟草cDNA文库,借助pGADT-Sfi AB载体上特殊酶切位点SfiⅠ,酶切检测水稻和烟草cDNA文库质量;以SsbX为诱饵,通过酵母双杂交技术(Y2H)从水稻和烟草cDNA文库中筛选在SD/-Ade/-Leu/-Trp/-His培养基上能够生长的阳性克隆;并利用β-gal试验验证阳性克隆;序列测定后,使用MEGA 4序列分析软件,并利用邻位相连法(neighbor-joining,NJ)对筛选获得的互作因子进行同源序列和系统进化树分析;利用荧光双分子互补试验(BiFC)于488 nm处黄色激发光和520—550 nm透射光、20×物镜下,在激光共聚焦显微镜(Leica TCS SP5-II)观察SsbX与烟草和水稻中互作因子的互作位点。【结果】水稻和烟草cDNA文库构建和质量检测结果显示,随机挑选20个克隆中水稻来源的cDNA插入在pGADT-Sfi AB载体上,平均片段大小1.0kb;随机挑选20个克隆中烟草来源的cDNA均插入在pGADT-Sfi AB载体上,平均片段大小1.2 kb,说明水稻和烟草的cDNA文库构建质量较好;Y2H和β-gal试验结果显示,SsbX可与烟草和水稻的ADF2(actin-depolymerization factor 2)蛋白互作,使酵母AH109能够在SD/-Ade/-Leu/-Trp/-His平板上生长,并且β-gal染色显示为蓝色。水稻Os ADF2编码139氨基酸,蛋白质分子量为15.9 k D,而烟草Nb ADF2编码137氨基酸,蛋白质分子量为15.kD,两者同源性达69.02%。同源性以及系统进化树分析显示,植物中ADF2广泛存在,同源性高达60%以上。双子叶植物烟草和拟南芥的ADF2同源性最高,相似性达69.05%;单子叶禾本科植物水稻和狗尾草的ADF2同源性最高,相似性为88.81%。BiFC试验结果显示,在488 nm波长的激光共聚焦显微镜下,仅SsbX和Os ADF2以及SsbX和Nb ADF2共同存在时,可在烟草细胞膜上显示黄色荧光,与阳性对照显示黄色荧光一致,说明SsbX可与Os ADF2或Nb ADF2互作,互作位点发生在植物细胞膜上。【结论】通过T3SS分泌的水稻条斑病菌中的SsbX,在植物细胞膜上与ADF2互作,从而激发植物的免疫性。这为进一步揭示SsbX如何激发植物产生HR的机制提供了依据。     

傅立叶近红外快速预测菜籽粕的中、酸性洗涤纤维的研究

为了快速测定菜籽粕中的中、酸性洗涤纤维,对73个不同地区的菜籽粕样品进行了傅立叶近红外光谱扫描以及中、酸性洗涤纤维的化学测定,根据光谱与化学值利用偏最小二乘法建立傅立叶近红外的预测模型,并对模型进行评价。结果表明,NDF和ADF的决定系数分别为97.03和95.57,矫正标准差分别为0.95和1.17。模型的准确度较好,外部检验后真值与化学值接近,说明该模型适合快速预测菜籽粕的中、酸性洗涤纤维的含量。     

日粮中添加硫酸钠对陕北白绒山羊瘤胃纤维素降解率的影响

【目的】研究含不同水平硫酸钠日粮对陕北白绒山羊瘤胃纤维素降解率的影响,为选择适宜的硫添加水平提供理论依据。【方法】选择4只健康、体质量（28～32 kg）相近且安装永久性瘤胃瘘管的陕北白绒山羊为试验动物,采用4×4拉丁方单因素试验设计,试验分4个时期进行,每个时期14 d,分别饲喂硫酸钠添加水平为0(对照组),2.0,4.8,6.4 g/kg的4种日粮,测定瘤胃内青贮饲料干物质（DM）、中性洗涤纤维（NDF）、酸性洗涤纤维（ADF）的动态降解率,计算青贮饲料瘤胃DM、NDF、ADF的有效降解率(PED),并进行显著性检验。【结果】与对照组相比,日粮中添加硫酸钠对瘤胃食糜外流速率（Kp）无显著影响;提高了瘤胃内青贮饲料DM、NDF、ADF的PED值,而且当硫酸钠添加水平分别为4.8 和6.4 g/kg时,PED值有显著或极显著提高。【结论】日粮中添加硫酸钠可以提高陕北白绒山羊非产绒期瘤胃内粗饲料纤维的PED值,且PED值随着硫酸钠添加水平的增加而增大,当硫酸钠水平为6.4 g/kg时,青贮玉米PED值最大,从而使青贮玉米得到了更好的利用。     

The effect of growth regulator on dry matter yield and some chemical components in selected grass species and cultivars

The work reported here was undertaken to determine the effect of the biostimulant Kelpak SL on some chemical components in selected grass. The experiment was a split-split-plot arrangement with three replicates. It was set up at the experimental facility of the Siedlce University of Natural Sciences and Humanities (Poland), in late April 2009. The following factors were examined: Kelpak SL applied at the rate of 2 dm³ ha^?1 vs. non-treated control (0 dm³ ha^?1), pure sown grass species and cultivars grown in monoculture: Dactylis glomerata L., cv. Amila and Tukan as well as Festulolium braunii (K. Richt.) A. Camus cv. Felopa and Agula. The results demonstrated that grass yield and nitrogen content in dry matter increased significantly following an application of Kelpak. The biostimulant significantly reduced fiber NDF (Neutral Detergent Fiber) and ADF (Acid Detergent Fiber) regardless of the remaining factors. Festulolium braunii cv. Agula had the highest nutritional value. Grass yields and concentration of the components examined clearly varied during the growing season.     

玉米秸秆DNF与ADF含量变化规律的研究

为了弄清不同品种、不同收获时间玉米秸秆营养成分变化情况，应用范氏洗涤纤维分析方法对10个品种、四个收获时期玉米秸秆中NDF、ADF含量进行了测定。结果表明：品种不同，四期秸杆中NDF和ADF含量平均值变化范围分别是62.4%～70.62%和38.31%～41.93%；收获时期不同，10个品种秸秆中NDF和ADF含量平均值变化范围分别是64.14%～70.48%和37.22%～43.55%。     

Effects of Drought on Nutritive Value of Kudzu

Kudzu (Pueraria montana), a vigorous, perennial warm-season invasive legume is widely spread in the southeastern United States and has the potential to be used as feed by ruminants during its growing season from May until first frost (usually in October). The purpose of this study was to determine the nutritive value of kudzu during a drought-prone growing season. Five samples of apical leaves and stems were harvested once a week from random locations within a 43-year-old kudzu infestation grown on a Cecil clay loam (fine, kaolinitic, thermic Typic Kanhapludults) at the Clemson University Experimental Forest (Clemson, S.C.). We report the effects of plant part, sampling date, mean air temperature (MAT), and precipitation on dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), calcium (Ca), magnesium (Mg), phosphorus (P), potassium (K), sulfur (S), zinc (Zn), copper (Cu), manganese (Mn), and iron (Fe) of the kudzu. Dry matter and CP were significantly greater in the apical leaf than in the stem; CP had a significant mean air temperature by plant part interaction. A significant temperature by plant part interaction also existed for Mg. Magnesium was greater in leaf than in the stem at the beginning of the growing season until the end of October, when small differences in Mg concentrations between stem and leaf were observed. Stem and leaf Ca concentrations were not significantly different. Calcium concentrations did vary across the dates (P?=?0.002). A significant temperature by plant part interaction existed for Mg concentrations (P?=?0.003), Ca to P ratio (P < 0.0001), P concentrations (P?=?0.0007), S (P < 0.0001), Zn (P?=?0.0053), Mn (P?=?0.0014), and Cu (P?=?0.006). Overall, kudzu's nutritive value as feed for ruminants during the growing season is highly variable; however, chemical composition was very comparable to other common forages. More frequent and intensive droughts predicted as a result of climate change may limit forage choices; however, kudzu maintains its forage potential for feeding both domestic and wild animals during drought-prone growing season.     

农民家庭人均纯收入与经济增长关系实证分析

对我国农民家庭人均纯收入与人均国内生产总值(GDP)之间的关系进行ADF平稳性检验、协整关系检验.结果表明,农民家庭人均纯收入与人均国内生产总值(GDP)之间具有长期的协整关系.建立误差修正模型,在协整的条件下对农民家庭人均纯收入与人均国内生产总值(GDP)的格兰杰因果关系进行分析,给出相关建议.     

鹅后段肠道液体外消化ADF、NDF的研究

本文旨在研究鹅肠道微生物体外利用ADF、NDF的情况。选择9只5周龄健康的扬州鹅公鹅,常规饲养至9周龄末将试验鹅急宰,取回肠、盲肠和直肠食糜,以苜蓿草粉为底物,分别接种鹅回肠、盲肠和直肠食糜滤液后进行体外厌氧培养。结果表明:在发酵过程中,3组pH在6.8~7.4之间变化;总还原糖浓度的总变化趋势是降低;总脱氢酶活性先增强后减弱;3组均可检测到半纤维素酶活性;回肠组和直肠组的ADF、NDF的消失率差异不显著(P>0.05),但与盲肠组均差异显著(P<0.05)。     

和龙麦饭石在反刍动物上的试验研究

选用１６头黑白花育成母牛，随机分成试Ⅰ、Ⅱ、Ⅲ和对照组．试验组的基础日粮中分别添加和龙麦饭石１．５％、２．０％、２．５％，经７０天的饲养试验和７天的消化试验，结果表明：试验组日增重比对照组分别提高８．８６％、１７．２２％、１７．７２％，差异极显著（Ｐ＜０．０１）；粗蛋白质消化率提高５．８１％、８．６５％、８．５６％，差异显著（Ｐ＜０．０５）；粗纤维消化率分别提高２．１７％、７．０８％、６．９７％；差异显著（Ｐ＜０．０５）．选用４只延边半细毛羊，采用４×４拉丁方设计，测定瘤胃ＰＨ值、瘤胃ＮＨ３－Ｎ、ＶＦＡ及ＮＤＦ，ＡＤＦ的消失率，结果表明：和龙麦饭石有调节瘤胃酸碱度作用和吸咐瘤胃ＮＨ３－Ｎ的作用；试验组瘤胃内ＴＶＦＡ浓度分别比对照组提高７．８９％、１７．６７％％、１６．１７％，差异极显著（Ｐ＜０．０１）；Ｃ２／Ｃ３值提高１３．５１％、１９．８２％、１８．９２％，差异极显著（Ｐ＜０．０１），ＮＤＦ消失率提高３．６３％、７．３９％、６．３１％，差异极显著（Ｐ＜０．０１）；ＡＤＦ消失率提高７．０１％、１３．６３％、１１．３８％；差异极显著（Ｐ＜０．０１）．