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991.
选取仔猪(7.06±0.18)kg、生长猪(44.54±9.04)kg和肥育猪(78.93±7.37)kg军牧一号去势公猪各15头,用于3个生长阶段的动物试验,每一阶段分为A、B、C 3组,其中A组为对照组,B、C以Glycinin或β-Conglycinin的提纯产物作为日粮唯一大豆蛋白来源,每组5个重复。仔猪在28日龄断奶,试验分组之前,猪均不接触任何豆科日粮。7 d试验期过后,收集消化道各段食糜,测定干物质和粗蛋白表观消化率。结果表明:Glycinin或β-Conglycinin降低仔猪或生长猪的生产性能以及干物质、粗蛋白在消化道各段的表观消化率(P<0.001),最终导致回肠养分表观消化率的绝对值与对照组相比减少3%~6%。2个生长阶段猪的粗蛋白质表观消化率只在胃中受抗原蛋白的影响有显著差异(Glycinin,P=0.005;β-Conglycinin,P=0.001),仔猪的下降程度大于生长猪。 相似文献
992.
NPY、TSH-β、CaBP-28K基因在鸭繁殖期组织中的表达水平分析 总被引:1,自引:0,他引:1
本研究对繁殖期高邮鸭神经肽Y(NPY)、促甲状腺激素β(TSH-β)、钙结合蛋白-D28K(CaBP-28K)基因在中枢神经组织和周围组织表达量进行了实时荧光定量分析。结果表明:NPY基因在下丘脑中表达量显著高于在垂体和在小肠中的表达量(P<0.05),在卵巢、心脏、肝脏、脾脏、肾脏、胰腺、子宫、胸肌、腿肌等9个部位呈痕量表达;TSH-β基因在垂体、小肠中表达量较高,显著高于其他组织(P<0.05);CaBP-28K基因在小肠表达量最多,其次是卵巢和肾脏,但均显著大于垂体中表达量(P<0.05),在其他测定部位呈痕量表达,就生殖轴而言,CaBP-28KmRNA的表达量表现为卵巢>垂体>下丘脑。本研究为了解高邮鸭繁殖期相关基因的表达特征和内分泌机制,指导高邮鸭选种选育提供了理论依据。 相似文献
993.
将构建的含鸡柔嫩艾美耳球虫(Eimeria tenella)CDPK和3-1E双抗原的真核重组质粒proEC,在14日龄和21日龄分别免疫AA肉鸡,28日龄感染5×104个E.tenella孢子化卵囊,观察其免疫保护效果.结果显示,攻虫后1周,与proC组相比,proEC组能显著增强淋巴细胞转化和血清抗体水平(P<0.05);与proE组和proC组相比,proEC组卵囊产量最低但差异不显著(P>0.05),其相对增重低于proE组和proC组.结果表明,proEC双抗原DNA疫苗对E.tenella攻虫表现出一定双抗原协同保护效应. 相似文献
994.
Creighton M. Litton Christian P. Giardina Gregory P. Asner 《Soil biology & biochemistry》2011,43(11):2315-2323
Soil-surface CO2 efflux (FS; ‘soil respiration’) accounts for ≥50% of the CO2 released annually by the terrestrial biosphere to the atmosphere, and the magnitude and variability of this flux are likely to be sensitive to climate change. We measured FS in nine permanent plots along a 5.2 °C mean annual temperature (MAT) gradient (13-18.2 °C) in Hawaiian tropical montane wet forests where substrate type and age, soil type, soil water balance, disturbance history, and canopy vegetation are constant. The objectives of this study were to quantify how the (i) magnitude, (ii) plot-level spatial variability, and (iii) plot-level diel variability of FS vary with MAT. To address the first objective, annual FS budgets were constructed by measuring instantaneous FS monthly in all plots for one year. For the second objective, we compared plot-level mean instantaneous FS in six plots derived from 8 versus 16 measurements, and conducted a power analysis to determine adequate sample sizes. For the third objective, we measured instantaneous FS hourly for 24 h in three plots (cool, intermediate and warm MATs). The magnitude of annual FS and the spatial variability of plot-level instantaneous FS increased linearly with MAT, likely due to concomitant increases in stand productivity. Mean plot-level instantaneous FS from 8 versus 16 measurements per plot yielded statistically similar patterns. The number of samples required to estimate plot-level instantaneous FS within 10% and 20% of the actual mean increased with MAT. In two of three plots examined, diel variability in instantaneous FS was significantly correlated with soil temperature but minimal diel fluctuations in soil temperature (<0.6 °C) resulted in minimal diel variability in FS. Our results suggest that as MAT increases in tropical montane wet forests, FS will increase and become more spatially variable if ecosystem characteristics and functioning undergo concurrent changes as measured along this gradient. However, diel variation in FS will remain a minor component of overall plot-level variation. 相似文献
995.
Biochar amendments to soils have been suggested as a strategy to sequester carbon and therefore mitigate global climate change. The enrichment of soils with charred materials also increases their fertility. This fertilising effect of biochar may be caused by various mechanisms; an acceleration of nutrient cycling has been suggested as one such mechanism. The rate-limiting step in nutrient cycling is thought to be the extracellular enzymatic attack on biological macromolecules. In this study, therefore, the effects of chestnut wood char (specific surface area 2.0 m2 g−1) and of activated carbon (specific surface area approximately 900 m2 g−1) on an extracellular enzymatic reaction involved in the degradation of cellulose (i.e., hydrolysis of cellobiose by β-glucosidase from Aspergillus niger) were investigated. Cellobiose was not adsorbed by chestnut wood char, whereas activated carbon absorbed more than 97% of it. Both charred materials adsorbed more than 99% of β-glucosidase. For chestnut wood char, adsorption of the enzyme caused a decrease of approximately 30% in the reaction rate, whereas for activated carbon, the nearly complete absorption of both substrate and enzyme entirely inhibited the reaction. These results show that β-glucosidase from A. niger retains most of its activity when adsorbed to chestnut wood char and that the reaction it catalyses in nature is only slightly affected by this charred material. On the other hand, a material characterised by a high specific surface area and high porosity, such as activated carbon, can make even a highly soluble substrate unavailable for soil enzymes and therefore completely inhibit the reaction. Thus, charred materials may affect nutrient cycling mainly by regulating the availability of substrates: the degradation of highly soluble substrates may be accelerated by materials with low specific surface area, which maintain an active and protected enzyme pool, whereas materials with high specific surface and high porosity may slow down the degradation by making substrates unavailable. 相似文献
996.
997.
建立了兽药粉剂中氯霉素类和硝基呋喃类共7种抗菌药物的液相色谱-串联质谱筛选方法。样品经水溶解,乙酸乙酯提取样品中的药物,OasisHLB固相萃取小柱净化,液相色谱-串联质谱仪测定。分别对该方法的检测限和专属性进行了实验室内和实验室外验证。结果表明,该方法简单、灵敏、特异性强,适用于兽药粉剂中氯霉素类和硝基呋喃类的定性筛选测定。 相似文献
998.
999.
目的 筛选泰妙菌素高产菌株。方法 以TMⅡ09—003为出发菌株,经UV照射180s后,将菌悬液均匀的涂布于加有0.8%的氯化锂平板上,在避光条件下于温度26℃~27℃,湿度60%~65%的环境下培养成熟后,进行挑取单菌落、初筛、复筛。以HPLC法测化学效价。结果 经UV照射180s后,氯化锂加量为0.8%剂量对菌株的致死率为88.6%。对用此剂量处理获得的诱变菌株进行了筛选,最终获得4支高产菌株,分别为:TMⅡ09—236、TMⅡ09—253、TMⅡ09—441和TMⅡ09—447。 相似文献
1000.
为了比较产后一段时期内酮病奶牛与健康奶牛血液生化指标的差异,为奶牛酮病的防控及兽医临床诊治提供理论依据。本研究选取吴忠市某集约化奶牛场待产奶牛共30头进行为期3周的血液生化指标监测,根据β-羟丁酸(BHBA)的浓度将奶牛分为酮病组和对照组并进行比较研究。结果显示,酮病组与对照组在生产当天(0 d)各项检测指标未出现显著性差异;酮病组奶牛β-羟丁酸浓度在产后7 d时较对照组极显著升高(P<0.01);天门冬氨酸氨基转移酶(AST)和总胆红素(T-bil)浓度在产后7 d和14 d时显著升高(P<0.05);血糖(Glu)浓度在产后7 d时显著降低(P<0.05),产后14 d时极显著降低(P<0.01);钙(Ca)、磷(P)浓度无显著性差异,但均低于正常参考值范围,出现低血钙、低血磷症。经分析发现,本场奶牛所患酮病为Ⅱ型酮病,酮病牛高发胎次为3~6胎,产后低血钙、低血磷、低血糖现象严重,同时奶牛酮病引发了机体肝脏功能损伤,影响母牛生产性能。 相似文献