嵌合型猪圆环病毒（PCV1—2）及PCV2 ORF2真核表达质粒对商品猪的免疫保护     

程旭  宋益  盛瑜  高崧  刘秀梵 《兽医大学学报》2009,(9):1097-1102

应用本实验室构建的嵌合型猪圆环病毒（PCV1—2）及真核表达质粒pcDNA3．1／V5-His-ORF2作为免疫原免疫母源抗体ELISA效价在0．07～0．60不等的商品猪,9头猪随机分为4组,1组（3头）肌肉注射免疫10^3.5 TCID50的PCV1-2／头,2组（2头）肌肉注射真核表达质粒200μg／头,3组（2头）肌肉注射空载体（pcDNA3．1）200μg／头,4组（2头）不免疫作为攻毒对照组。于免疫后42d,PCV1—2组及真核表达质粒组产生了PCV2抗体。免疫后42d所有组攻毒PCV2和PRRSV,剂量分别为2×10^4.5 TCID50／头和10^6 TCID50／头。攻毒后21d,攻毒对照组猪淋巴结比免疫组显著肿大,免疫组猪血清、淋巴结中PCV2病毒栽量低于对照组,攻毒对照组猪淋巴结中PCV2抗原含量高于免疫组。这些结果表明,嵌合型PCV1-2及真核表达质粒肌肉注射免疫商品猪后,对PCV2感染能产生保护性免疫应答,有可能成为候选疫苗。  相似文献   

重组痘苗病毒载体研究进展   总被引：3，自引：0，他引：3  

张仁舟  杨松涛  夏咸柱 《动物医学进展》2009,30(1)

通过同源重组将外源基因插入到痘苗病毒基因组内,以痘苗病毒为载体使外源基因在动物细胞内表达以获得目的蛋白,从而达到免疫接种的目的.痘苗病毒有宿主范围广、允许插入外源基因片段长、可通过多种途径进行接种、能诱导体液和细胞免疫反应及易于增殖生产等优点,在疫苗研制中得到了广泛的应用.以痘苗病毒作为载体表达狂犬病病毒糖蛋白研制成的狂犬病疫苗已经在野生动物狂犬病控制中发挥了巨大的作用,用痘苗病毒研制的艾滋病病毒疫苗也已经进入了临床试验.  相似文献   

鲁单818玉米夏季抢茬直播高产栽培技术     

赵冬梅 《现代农业科技》2012,(11):32+34

根据鲁单818玉米特征特性,介绍了鲁单818玉米夏季抢茬直播高产栽培技术,包括抢茬直播、科学施肥、合理管水、田间管理、病虫草害及其他灾害防治、适时收获等内容,以期为该品种的栽培提供技术参考。  相似文献   

栓皮栎直播造林技术     

曹英坤 《北京农业》2012,(33):93

对栓皮栎直播造林技术进行相关探讨。  相似文献   

Feeding Strategies for Rearing Replacement Heifers in Small-scale Dairy Production Systems in the Highlands of Central Mexico     

Arriaga-Jordán CM  García-Martínez A  Albarrán-Portillo B  Espinoza-Ortega A  Castelán-Ortega OA 《Tropical animal health and production》2003,35(3):259-269

The growth of Holstein heifers in the campesino dairy systems in the highlands of Mexico was evaluated in three feeding strategies. Thirty-three heifers from 11 farmers, grouped according to strategy, were weighed every 14 days for 28 weeks. The live weight change over each 14-day period was estimated by individually regressing live weight over period, taking the regression coefficient as an unbiased estimate of live weight change. Regression coefficients were analysed as a randomized design with feeding strategies as treatments. Strategies were as follows: S1: grazed or cut pasture all year, maize silage and maize straw in the dry season, and 1.0–1.5 kg concentrate/heifer per day. S2: maize straw in the dry season, cut pasture forage, grazing of native grass, weeds from maize fields, and 1.0–1.5 kg concentrate/heifer per day. S3: maize straw in the dry season, grazed native grasses and weeds in the rainy season. Live weight gains were: S1, 0.511 kg/heifer per day; S2, 0.271 kg/heifer per day; and S3, 0.252 kg/heifer per day. Despite the better gains in S1, they are 24% below recommendations, arriving to service at 20 months of age. Not rearing their replacements may be a better alternative for campesino farmers under current economic conditions.  相似文献   

Effect of Supplementation with Leguminous Crop Residues or Concentrates on the Voluntary Intake and Performance of Kirdi Sheep   总被引：1，自引：1，他引：0  

Ngwa AT  Tawah CL 《Tropical animal health and production》2002,34(1):65-73

Twenty young Kirdi (West African Dwarf) rams, averaging 22 kg live weight and 15 months of age, were randomly assigned to four feeding groups of 5 animals each. The groups were subjected to an 8-week feeding trial to determine the effect of different protein supplements on their voluntary intake of rice straw and on their performance. The animals in one of the groups were maintained on a daily basal diet of rice straw given ad libitum and 250 g of rice bran per animal (control). Other groups were fed the basal diet, supplemented with 300 g of groundnut haulms (GH diet), 45 g of cotton seed cake (CSC diet) or 210 g of chopped cowpea vines (CPV diet) per animal per day. The average daily weight gains of the animals feeding on the control, GH, CSC and CPV diets were 20.00, 48.93, 52.14 and 49.29 g, respectively. The gains in live weight of the supplemented groups did not differ significantly (p>0.05), but there was a difference (p<0.05) in live weight gain between the supplemented groups and the control. The differences in intake of rice straw among the groups were highly significant (p<0.01). Cotton seed cake increased (p<0.01) the intake, while feeding crop residues tended to depress the intake of rice straw. Variations in the height at withers, heart girth and scapulo-ischial length did not differ significantly (p>0.05) among the groups. In terms of live weight gain and intake of rice straw, cotton seed cake was the most effective supplement, but, since the crop residues are more readily available to farmers in this area of the country, they merit more attention.  相似文献   

禽疱疹病毒活载体疫苗研究进展     

王梦阁  吴英  程安春  汪铭书  朱德康  贾仁勇  刘马峰  陈舜  赵新新  杨乔  张沙秋  黄娟  刘韵雅  张玲  于艳玲 《中国农业科技导报》2020,22(3):85-93

禽疱疹病毒主要包括α疱疹病毒亚科的鸡马立克氏病毒( Mareks disease virus, MDV)、传染性喉气管炎病毒( infectious laryngotracheitis virus, IBDV )和鸭肠炎病毒( duck enteritis virus, DEV )。作为疱疹病毒家族的成员,禽疱疹病毒基因组庞大,存在多个复制非必需区,可容纳多个外源基因的插入,是表达其他禽类病原抗原基因的理想载体。总结了禽疱疹病毒的构建方法、外源基因表达水平,并对MDV、IBDV和DEV 三种禽疱疹病毒的不同重组病毒疫苗免疫效果评价进行归纳,旨在为畜禽传染病防治提供参考依据。  相似文献   

基于网络直播平台创新生态文明教育的路径研究     

张童彤  黄志斌 《安徽农业大学学报》2020,29(2):32-36,115

新媒体背景下,网络直播以其内容多样、传播高效、即时互动等特点受到了广泛关注。蓬勃兴起的网络直播给生态文明教育带来了机遇和挑战。目前,推动网络直播与生态文明教育融合发展的问题主要在于直播平台对生态文明教育属意不够、生态失范行为时有出现、监管体系尚不完善、立法相对滞后等。各部门应当协同发力为生态文明教育做好引流和宣传工作;努力创新生态文明教育模式,不断完善生态文明教育直播内容;进一步加强对网络直播的监管与治理,积极营造良好的生态文化氛围。基于网络直播平台创新生态文明教育,符合绿色发展和生态文明的时代潮流,是切实提高生态文明教育质量和效果的重要路径。  相似文献   

湖北白猪活体性状与胴体性状间的典型相关分析   总被引：8，自引：0，他引：8  

郭万正  梅书棋  徐子清  吴金英  孙华 《华中农业大学学报》1999,18(1):49-52

通过对湖北白猪新系９０头样本的活体性状的９个变量与胴体性状的１０个变量之间的典型相关分析,得出了决定两组性状间相关性的三对典型变量。湖北白猪活体性状与胴体性状之间的相关主要是由：腹围,臀宽及活体膘厚与板油率密切相关。胸围,胸围,臀长,臀围与屠宰率及后腿比例密切相关,体长,胸围与瘦肉率和肥肉率间的较强相关所决定的。分析表明：湖北白猪新品系具有前胸开阔,腹部紧凑,臂部丰满,背膘薄的特点。选育中要加强  相似文献   

Aquaculture of the sand star,Astropecten indicus Döderlein, 1888, as a step toward the sustainable aquaculture of harlequin shrimp,Hymenocera picta Dana, 1852     

Jarunan Pratoomyot  Thammasak Torcharoen  Pairach Thongra-ar  Andrew P. Shinn 《Journal of the World Aquaculture Society》2020,51(1):282-286

Ornamental harlequin shrimp, Hymenocera picta, are commonly maintained on live comet sea stars, Linckia multifora. In Thailand, both species are commonly collected from the wild, raising concerns regarding the sustainability of such practices. As a step toward the sustainable aquaculture of both, methods of their culture and nutrition were investigated. Under captive conditions, harlequin shrimp readily predate, and can be maintained upon the astropectinid sand star Astropecten indicus as an alternative live feed during periods when comet sea stars are unavailable. Wild A. indicus subsequently spawned multiple times shortly after their collection; the eggs (300 μm diameter) were transferred to static aquaria. Following the appearance of planktonic bipinnaria, larval sea stars were fed a 50:50 Chaetoceros calcitrans and Isochrysis galbana diet. Eleven days post-transfer, brachiolaria stages began to settle; stages were then fed concentrated I. galbana. When specimens measured 1–2 mm in diameter, they were transferred onto an in-house formulated Amphiprion diet (>50% protein, >16% lipid). Sea stars were graded regularly; they matured and spawned after 6 months. Populations were maintained for more than three successive generations, demonstrating their ready culture under captive conditions, representing the first harvestable aquaculture of a sea star as a step toward supporting the sustainable culture of a primary, marine species.  相似文献