Effect of forage conservation method on microbial flora and fermentation pattern in forage and in equine colon and faeces     

C.E. Müller  D. von Rosen  P. Udn 《Livestock Science》2008,119(1-3):116-128

The influence of forage conservation method on microbial and chemical composition in forage and on colon content and faeces in horses fed with the forages was investigated. Hay (815 g DM/kg), haylage (548 g DM/kg) and silage (343 g DM/kg) was produced from the same grass crop and fed to four fistulated horses in a crossover study. Horses were sampled in right ventral colon and of faeces after a feeding period of 21 days (for each forage). Fermentation kinetics of right ventral colon was also studied on two subsequent days in each period, with sampling times immediately before and 2, 4, 8 and 12 h after the morning meal. Forage conservation method influenced microbial and chemical composition of the forages. Silage differed from haylage and hay in more variables than haylage differed from hay. However, the different forage types had similar influence on microbial and chemical composition of right ventral colon content and faeces in horses at Day 21, with the exception of counts of Streptococci which were highest when horses were fed with hay. However, interaction among forage types and sampling locations (right ventral colon and faeces) was also present for Streptococci as well as for pH. In general, pH was lower and counts of lactate utilizing and lactate producing bacteria were higher in faeces compared to right ventral colon. Fermentation kinetics in colon varied little among forage types and sampling times, and no interaction between forage types and sampling times were found, indicating that silage, haylage and hay had very similar fermentation kinetics in right ventral colon of horses. In conclusion, silage, haylage and hay produced from the same grass crop tended to produce similar responses in microbial and chemical composition in right ventral colon and faeces in horses fed with the forages.  相似文献   

Soil organic matter dynamics after the conversion of arable land to pasture   总被引：4，自引：0，他引：4  

P. F. A. M. Römkens  Johannes van der Plicht  Jan Hassink 《Biology and Fertility of Soils》1999,28(3):277-284

 Conversion of arable land (maize) to pasture will affect the soil organic matter (SOM) content. Changes in the SOM content were studied using a size- and density-fractionation method and ¹³C analysis. Twenty-six years of maize cropping had resulted in a depletion of carbon stored in the macro-organic fractions (>150 μm) and an increase in the <20 μm fraction. Maize-derived carbon in the upper 20 cm increased from 10% in the finest fraction (<20 μm) to 91% in the coarse (>250 μm), light (b.d. <1.13 g cm^–3) fractions. Pasture installation resulted in a rapid recovery of the total SOM content. Up to 90% of the pasture-derived carbon that was mineralized during maize cropping was replaced within 9 years. Especially the medium and coarse size (>150 μm) and light (b.d. <1.13 g cm^–3) fractions were almost completely regenerated by input of root-derived SOM. The amount of medium-weight and heavy macro-organic fractions (>150 μm; b.d. >1.13 g cm^–3) in the 0- to 20-cm layer was still 40–50% lower than in the continuous pasture plots. Average half-life times calculated from ¹³C analyses ranged from 7 years in the light fractions to 56 years in heavy fractions. Fractionation results and ¹³C data indicated that mechanical disturbance (plowing) during maize cropping had resulted in vertical displacement of dispersed soil carbon from the 0- to 20-cm layer down to 60–80 cm. Conversion of arable land to pasture, therefore, not only causes a regeneration of the soil carbon content, it also reduces the risk of contaminant transport by dispersed soil carbon. Received: 10 March 1998  相似文献   

草鱼LPL基因的表达及饥饿和再投喂对其影响     

吉红  苏尚顺  刘茜  曹艳姿  杨公社  林亚秋  奥宏海 《水产学报》2009,33(6):980-986

获得了草鱼脂蛋白脂酶(lipoprotein lipase, LPL)部分cDNA序列（GenBank注册号为FJ612596）,并进行了序列同源性分析;采用半定量反转录聚合酶链式反应（SQ-RT-PCR）方法,检测了LPL基因在草鱼不同组织和不同发育阶段脂肪细胞中的表达状况;研究了饥饿和再投喂对草鱼肝胰脏LPL基因表达的影响。结果显示,所获得的草鱼LPL部分cDNA序列长度为360 bp,与其它物种的同源性为70%~89%; LPL基因在肝胰脏、肌肉、心脏、鳃、腹腔脂肪组织中均表达,其中在腹腔脂肪组织中表达丰度最高,在鳃中表达丰度最低;在成熟脂肪细胞中的表达丰度显著高于基质脉管组分（stromal vascular fraction,SVF）细胞;草鱼LPL基因表达水平在饥饿48 h后显著升高,再次投喂后12 h,回复到0 h的表达水平。研究表明,草鱼LPL在不同组织及脂肪细胞分化的起始和终末阶段均有表达,显示其在草鱼不同组织和脂肪细胞分化中具有重要作用,同时,其表达水平受营养状况的调控。论文首次克隆得到草鱼LPL基因部分cDNA序列,并对其进行了表达分析,研究结果可为LPL在鱼类脂质代谢中的作用研究提供参考和依据。  相似文献   

菌草灵芝孢子粉增强免疫调节作用研究     

范青生胡居吾  肖小年 《中国食用菌》2005,24(5):39-41

120只SPF级昆明种雌性小鼠平均分成3组，菌草灵芝孢子粉分三个剂量组给小鼠灌胃，共30d。测定小鼠的体重、免疫器官脏器／体重比值、迟发型变态反应（DTH）、ConA诱导的小鼠淋巴细胞转化能力、抗体生成细胞数、半数溶血值（HC50）、单核一巨噬细胞碳廓清、巨噬细胞吞噬鸡红细胞吞噬率指标。结果：0．150g／kg．bw剂量能提高小鼠的半数溶血值（P〈0．05）；0．450g／kg．bw剂量能提高小鼠迟发型变态反应（DTH）能力、ConA诱导的淋巴细胞转化能力、增加抗体生成细胞数（P〈0．05）；菌草灵芝孢子粉对小鼠体重增长、胸噱体重比值、脾脏体重比值、单核-巨噬细胞碳廓清能力、小鼠巨噬细胞吞噬鸡红细胞的能力均无明显影响（P〉0．05）。  相似文献   

草鱼出血病分子流行病学及GCRV多样性研究     

黄毅昌  雷燕  杨玉滔  闫秀英  简纪常  吴灶和 《安徽农业科学》2016,(11)

[目的]分析不同基因型GCRV分离株与患草鱼出血病草鱼症状的相关性。[方法]采用RT-PCR检测患病草鱼,应用生物信息学方法分析基因型内和基因型间不同分离株间的差异。[结果]对近3年来草鱼出血病分子流行病学分析发现,患草鱼出血病病鱼多为"肠炎型"症状,且检测发现其病原多属于GCRV基因型Ⅲ型。对GCRV的多样性分析表明,不同分离株同源蛋白的同源率高达93%以上,却被给予完全不同的名称,给GCRV多样性研究带来一定的困难;同一基因型不同分离株同源蛋白间的变异位点较少,且功能位点发生变异的更少;不同基因型不同分离株同源蛋白间的保守位点较少,且这些保守位点中只有极少数位点为功能位点;不同基因型分离株同源结构蛋白间存在较大的差异,且同源非结构蛋白间的差异更为显著。[结论]草鱼出血病不同临床症状可能与其病原基因型不同有关。  相似文献   

临界氮浓度稀释模型在牧草种子生产中的应用前景     

陈玲玲  毛培胜  王明亚  汪辉  郑慧敏  陈泉竹  闫慧芳 《草地学报》2015,23(2):231-236

氮素是影响牧草种子产量的关键因素,氮素对于植株分蘖、干物质生产、花序形成、产量组分动态变化等均具有影响.文章主要从临界氮浓度稀释模型的概念、构建方法、研究现状、应用等方面进行了综述,提出临界氮浓度稀释模型在实际生产中应用时存在的问题,并对其在牧草种子生产中的应用前景进行了展望.  相似文献   

联户规模对高寒草场质量的影响分析——以甘肃玛曲为例   总被引：1，自引：0，他引：1  

韦惠兰  郭达 《草地学报》2014,22(6):1147-1152

通过测定不同规模联户管理下草场的可食草盖度、牧草高度、草场鼠洞数量、毒杂草比例及地上生物量等衡量草场质量的指标,统计分析后得出相比较单户、小联户与大联户而言,中联户管理的草场具有更高的草场盖度、牧草高度及地上生物量(EVI值),具有更少的鼠洞数量及更低的毒杂草比例,即由中联户管理的草场其质量最高.在此基础上以经济学视角分析草场质量差异的人文因素,表明单户或小联户具有较强的管理因素制约及较弱的自然因素制约,大联户具有较强的自然因素制约及较弱的管理因素制约;这3种联户内成员均会由于制约不足而出现增加饲养量的情况,造成过载放牧,并最终降低草场质量.中联户在较强的管理因素及自然因素的共同制约下,其内部成员均无增加饲养量的动机,因此整个联户将不会或很少出现过载放牧的情况.  相似文献   

Evaluation of functional diversity in rhizobacterial taxa of a wild grass (Saccharum ravennae) colonizing abandoned fly ash dumps in Delhi urban ecosystem     

Nupur Rau 《Soil biology & biochemistry》2009,41(4):813-821

Metal rich fly ash dumps may serve as repository of ecologically useful multi-functional rhizobacteria having potential use in the development of vegetation at the dumps. Therefore, in the present study bacteria from the rhizosphere of a wild perennial grass colonizing Indraprastha and Badarpur fly ash dumps of Delhi region were purified, identified and functionally characterized. The fly ash had low levels of nutrients, moisture and organic matter coupled with toxic levels of heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn). Both the dumps were mostly barren except for a few patches of Saccharum ravennae and some weedy species. Sixty five dominant, morphologically distinct rhizobacteria were purified, which belonged to 18 genera and 38 species. Gram-positive bacteria were dominating in the fly ash environment. Bacillus spp. and Paenibacillus spp. were common at both the dumps. Multi-metal tolerance was shown by diverse bacterial taxa. The minimum inhibitory concentration (MIC) was highest for As (12.5-20.0 mM) and Pb (7.5-10.0 mM), although many rhizobacteria also possessed significant tolerance to Cr, Zn, Ni, Cu, Co and Cd. The tolerance profiles of rhizobacteria to different metals may be ranked in the decreasing order as As > Pb > Cr > Zn > Ni > Cu > Co > Cd > Hg. Majority of rhizobacteria showed good siderophore activity. Multiple-metal tolerance was also coupled with high siderophore production in some of the isolates (Microbacterium barkeri IPSr74, Serratia marcescens IPSr90 and IPSr82, Enterococcus casseliflavus BPSr32, Bacillus sp. IPSr80, Pseudomonas aeruginosa BPSr43 and Brochothrix campestris BPSr3). Most of the bacteria could grow on nitrogen-deficient medium. However, the dominant nitrogen-fixers reported from the rhizosphere of other Saccharum species were not detected. S. marcescens IPSr90 was the only rhizobacterium, which showed ACC-deaminase (ACCD) activity. Proportion of phosphate-solubilizing bacteria was high. Considerable improvement in the seedling establishment, plant weight and shoot length in rhizobacterial inoculated plants of S. ravennae in fly ash environment indicated the significance of rhizobacteria in its colonization and spread to the dumps. Representative rhizobacteria, with high MIC (for most of the metals) and good plant growth promoting (PGP) traits comparable to commercially useful bacterial inoculants were identified as S. marcescens IPSr82 and IPSr90, P. aeruginosa BPSr43, Paenibacillus larvae BPSr106, Arthrobacter ureafaciens BPSr55, Paenibacillus azotofixans BPSr107 and E. casseliflavus BPSr32. S. ravennae and some of these rhizobacteria may be potentially useful for the development of inoculation technologies for conversion of barren fly ash dumps into ecologically and economically productive habitats.  相似文献   

海南坡鹿饲草粗蛋白质和微量元素含量与喜食性的关系   总被引：2，自引：0，他引：2  

周圻  何瑞国  李翔  韩杜  李善元  林贤梅 《草地学报》2004,12(1):36-39

在海南大田国家级自然保护区围栏内,测定海南坡鹿饲草的喜食性;采集坡鹿经常采食的草本植物和灌木各18种,测定其粗蛋白质、铁、锰、锌和铜含量,并分析其与饲草喜食性的相关关系.结果显示,随着粗蛋白质和微量元素含量增加,饲草的喜食性显著提高,海南坡鹿优先摄取粗蛋白质和微量元素含量丰富的饲草.灌木类饲草的粗蛋白质、铁、锰、锌和铜含量分别为12.24%、265.44、61.43、26.72和17.82mg/kg,均显著高于草本类饲草含量(依次为9.39%、142.67、34.05、13.67和9.44mg/kg).灌木是海南坡鹿旱季长达半年多时间里在大田保护区围栏内得以维持平衡的生态营养需要的重要营养源.对海南坡鹿饲草资源量的研究表明,大田保护区围栏内坡鹿喜食的灌木类饲草的可采食资源量在逐步减少,这是由于它们被坡鹿长期选择性采食所导致的.  相似文献   

Prediction of Hourly Pasture Dry Matter Intake in Horses     

L.E. DowlerP.D. Siciliano 《Journal of Equine Veterinary Science》2009

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