奶牛热应激缓解剂效果及机制初探   总被引：1，自引：0，他引：1  

李高凯  梁学武  刘庆华 《中国牛业科学》2006,33(3):19-22

根据胎次、泌乳天数、产奶量将临床健康、平均泌乳146 d、产奶量17.49 kg/头.d的74头中国荷斯坦泌乳牛随机配对分为2组,试验牛集中饲养于同一栋棚舍式拴系牛舍中,按照前后交叉试设计,每期预饲期7 d,正式试验期21 d,前后试验间歇期15 d。试验期牛舍平均温度为31.07℃,温湿指数(TH I)为82.61。对照组饲喂基础日粮,试验组在此基础上添加1%奶牛热应激缓解剂。结果表明:1.试验组体温较对照组显著降低(P<0.05),呼吸和脉搏也有降低的趋势,但差异不显著(P>0.05);2.试验组干物质进食量(DM I)较对照组提高6.4%(P<0.05),4?M奶量较对照组提高5.41%(P<0.05),乳脂率、乳蛋白率和乳总固体物含量差异不显著(P>0.05);3.试验组血液一氧化氮合酶(NOS)活性较对照组显著提高(P<0.05),诱导型一氧化氮合酶(iNOS)活性显著降低(P<0.05),热应激缓解剂可能的作用机制是一方面提高热应激期奶牛血液结构型一氧化氮合酶(cNOS)活性,随之激活CM产生短时效适量的NO,使外周血管舒张,机体通过血流将体内的热量运至皮肤进行蒸发散热;另一方面减弱奶牛的甲状腺活动,降低代谢率,减少产热量。  相似文献   

鳞毛蕨(Dryopteris filix-mas)天山云杉林种群结构分析   总被引：7，自引：5，他引：7  

刘翠玲  潘存德  梁瀛  刘政新 《干旱区研究》2006,23(1):60-65

以西天山国家自然保护区内1 hm2原始鳞毛蕨(Dryopteris filix-mas)天山云杉纯林临时标准地调查材料为基础,分析鳞毛蕨天山云杉林胸径、树高和年龄结构、种群存活曲线以及基本测树因子之间的相互关系.结果表明:①鳞毛蕨天山云杉纯林种群结构稳定,无论是胸径、树高抑或年龄,均呈现出明显的倒"J"型,属于典型的异龄林林分结构,林木更新良好,在其自维持过程中不断有大量小径木更新补充;②林木株数随胸径、树高和年龄的增大,呈负指数函数或负幂函数递减;③树木胸径和树高随年龄的增大,按理查兹生长曲线递增;④胸径与树高的关系为非线性关系.此外,种群存活曲线总体趋势呈现"凹"型,表明该种群是一个连续更新的种群,在林分生长发育过程主要受到小尺度林冠干扰的影响.  相似文献   

宁夏大风日数气候变化及其对沙尘天气的影响   总被引：6，自引：1，他引：6  

张智  郑广芬  林莉  陈晓娟  梁旭 《干旱区资源与环境》2006,20(4):30-34

本文利用宁夏23个气象台站1961—2004年共44a的大风日数、沙尘暴日数、扬沙日数资料,统计分析了宁夏大风日数的空间分布和时间分布特征,结果表明:近44a来宁夏存在2个大风中心———北部的惠农和东部的麻黄山,西南部的隆德大风日数最少,春季是宁夏各站大风日数最多的季节;20世纪60、70年代是宁夏大风日数明显偏多期,80、90年代是偏少期,21世纪初期比20世纪80、90年代略有增加;大风日数气候倾向率16个站为负值,7个站为正值;大武口———石炭井一带、麻黄山、兴仁、泾源是大风日出现的沙尘暴次数占其沙尘暴出现总次数的百分率高值区,陶乐———盐池一带、中卫是低值区,且大风中心区与沙尘暴频发区不重合;惠农、麻黄山是大风日出现的扬沙次数占扬沙出现总次数的百分率高值区,陶乐、永宁、盐池、中卫是低值区;年平均大风日数、年大风日出现沙尘暴次数及扬沙次数均呈减少趋势,时间曲线变化趋势也相同。  相似文献   

Whole Genome Methylation Variation Analysis of Longissimus Dorsi Between Tan Sheep and Hu Sheep     

YUE Caijuan  LIANG Xiaojun  WANG Xiuqin  MA Qing  MA Jifeng  ZHANG Junli  WANG Xiaowei  Eerhehua 《中国畜牧兽医》2007,47(10):3058-3068

It aimed to identify the differential methylation region (DMR) and differential methylation gene (DMG) through the analysis of the genome-wide methylation difference of the longest muscle of the sheep's back of different breeds of sheep,and laid the foundation for the analysis of the differences in sheep skeletal muscle development.In this study,one-year-old sheep(Tan sheep and Hu sheep and Tan-Hu F2) were sanned by the whole genome bisulfite sequencing method(WGBS).The degree of methylation and differentially methylated region in the whole genome DNA of longissimus dorsi(LD) muscle were studied to explore the difference of DNA methylation in level in sheep.The results showed that the methylation (mC) rates of cytosine (C) were 3.55%,3.18% and 3.56% in Tan sheep,Hu sheep and Tan-Hu F2,respectively.A total of 97 731 DMRs and 10 784 related DMGs were detected.In CG,CHH and CHG sequences,the methylation levels of the three groups were not significantly different.419 GO terms and 20 related signal pathways were detected by GO and KEGG analysis,respectively,which were showed to be significantly enriched in cellular process,cell part,binding,long-term depression,and so on.Five candidate genes,ACTA2、ROCK1、CALD1、MYH3 and MYH10 were sreened out in muscle tissues.This study provided genome-wide methylation of pattern of three groups (Tan sheep and Hu sheep and Tan-Hu F2).The results provided reference information for the epigenetic study of Tan sheep and screened candidate genes related to muscle development and meat quality.  相似文献   

Genome-wide Association Study on Alive Litter Size Trait in Bama Xiang Pigs     

MO Jiayuan  GAO Jiuyu  FENG Lingli  LI Yueyue  TIAN Weilong  LIU Xiaoxiao  CHENG Feng  LIANG Liang  LEI Shuqiao  WEN Wei  LIANG Jing  LAN Ganqiu 《中国畜牧兽医》2007,47(12):3965-3975

In order to identify the molecular markers related to alive litter size of Bama Xiang pigs,the genome-wide association study (GWAS) was used to map and screen the candidate genes affecting the alive litter size trait.Ear tissue samples of 297 Bama Xiang pigs with multiple parity records were collected,and DNA was extracted and genotyped by porcine 50K SNP beadchip.After quality control and genotype imputation,the alive litter size of Bama Xiang pigs were GWAS by Tassel.The results showed that the average number born alive per litter of Bama Xiang pigs increased gradually with the increasing of parity in the range of 1-9 parities.A total of 32 816 SNPs were obtained after quality control and filtration.8 SNPs related to alive litter size of Bama Xiang pigs were screened by genome-wide association analysis,which were significant at genome or chromosome level.Based on the enrichment analysis of the coding genes in the region between 500 kb upstream and downstream of the associated significant SNP loci,and the QTL regions and gene functions related to porcine reproductive traits,4 genes (CAPZB,MSH3,CITED2 and HSD17B7) were finally identified to be candidate genes related to alive litter size of Bama Xiang pigs.  相似文献   

不同蛋白质水平条件下氨基酸平衡日粮对生长猪氮、磷及能量代谢的影响   总被引：8，自引：0，他引：8  

梁福广  何欣  马秋刚  宋春玲  计成 《中国畜牧杂志》2006,42(13):23-26

选用平均体重为(40±2)kg杜长大三元杂交去势公猪3头,按3×3的拉丁方进行试验设计,试验分3期,每期为7 d,采用全收粪法,研究不同蛋白质(CP)水平的氨基酸平衡日粮CP水平分别为14%、16%和18%)对氮、磷及能量代谢的影响。结果表明:不同蛋白质水平日粮处理间的氮表观消化率差异不显(著P>0.05),氮的沉积率以14%CP和16%CP组显著高于18%CP组(P<0.05),而14%CP和16%CP组之间无显著差异(P>0.05)。粪氮排出量14%CP日粮组显著低于16%CP和18%CP日粮组(P<0.05),16%CP日粮组和18%CP日粮组间无显著差异(P>0.05)。随着日粮蛋白质水平下降,生长猪的氮排出量、粪氮和尿氮均减少,总排泄氮中尿氮的比例较大,而粪氮则较少。不同蛋白质水平日粮对磷和能量的消化利用无显著影响(P>0.05)。  相似文献   

4味中药及其与抗菌药的复方制剂的MIC测定   总被引：3，自引：0，他引：3  

司红彬  梁松林  许桂芹  王世坤  胡功政 《中国兽药杂志》2006,40(2):31-34

用改进的试管两倍稀释法测定了黄连、鱼腥草、大青叶和苦参4味中药及其相互配伍（1：1）对标准大肠杆菌的最小抑菌浓度和4味中药与抗菌药配伍（1000：1）对临床分离鸡大肠杆菌的最小抑菌浓度。结果表明，4味中药及其相互配伍对大肠杆菌标准株有一定的抑制作用，其MIC值介于3．91—62．50mg／mL之间，其中大青叶和鱼腥草以1：l配伍对大肠杆菌抑菌效果最好，MIC为3．91mg／mL；对临床分离株，单方药中黄连抑菌效果最好，MIC为31．25mg／mL，24种复方药中，黄连和盐酸多西环素或加替沙星以1000：1配伍的抑菌效果最好，其MIC为3．91mg／mL。  相似文献   

金耳发酵液对糖尿病小鼠降血糖作用的研究     

苏槟楠  王常青  韩建欣  刘彦萍  徐宏英  王慕华  梁秋兰 《中国食用菌》2006,25(5):43-44

研究表明，金耳发酵液对四氧嘧啶诱导的糖尿病小鼠有降血糖作用，同模型对照组相比．大剂量组差异显著（P〈0.05）；同时，大剂量组对糖尿病小鼠摄食、饮水量的减少及体重的增加均有显著影响（P〈0.05）  相似文献   

Detection and analyses of coagulation and fibrolysis factor mRNA levels in tissue of hepatocellular carcinoma patients     

ZHOU Qi  LI Shao-qiang  LIANG Li-jian  PENG Bao-gang  ZHEN Yu-yang  SU Cai-kun 《园艺学报》2006,22(7):1348-1352

AIM:To detect the mRNA expression of tissue factor (TF), urokinase-type plasminogen activator (u-PA) and urokinase-type plasminogen activator receptor (u-PAR) in the samples of hepatocellular carcinoma (HCC) and adjacent tissue, and to elucidate their association with clinical significance. METHODS:The mRNA levels of TF, u-PA and u-PAR in 27 human HCC tissue samples with their adjacent tissue samples and 27 normal liver tissues were detected by RT-PCR. The relationship between the mRNA expression and their clinic-pathological data were also analyzed. RESULTS:The expressive rate of TF, uPA and uPAR in HCC tissue samples was 62.96% (17/27), 70.37% (19/27), 77.78% (21/27), respectively and relative expression intensity of TF, uPA and uPAR were 0.567±0.268, 0.964±0.458 and 0.784±0.322, respectively, which were significantly higher than those in adjacent tissue group and normal liver group (P<0.05). TF, uPA and uPAR mRNA levels were all significantly higher in larger size and in the invasive and metastatic subgroup (P<0.05). There had positive relationship between the mRNA expressions of these three factors. CONCLUSION:The results indicate that TF, uPA and uPAR might play an important role in hepatic carcinogenesis, invasiveness and metastasis.  相似文献   

Influence of Egb on the expression of Bcl-2 in vascular smooth muscle cells     

DONG Shao-hong  LIANG Xin-jian 《园艺学报》2006,22(6):1243-1244

  相似文献