内蒙古红豆草黄萎病菌的分离鉴定及其生物学特性

依照柯赫氏法则,利用形态学结合分子生物学的方法首次对内蒙古自治区呼和浩特市中国农科院草原研究所沙尔沁基地红豆草疑似黄萎病的病样进行分离和鉴定,利用蘸根接种法对病原菌的致病性进行测定.同时,首次在室内条件下对病菌的生物学特性,如生长最适温度、酸碱度以及碳源、氮源对病原菌生长速率和产孢量的影响进行了研究.结果表明,引起沙尔...     

山东小尾寒羊研究概况

介绍了山东小尾寒羊的研究概况 ,主要内容包括该品种的繁殖性能、屠宰性能、杂交利用等方面的最新研究成果 ,比较全面地阐述了山东小尾寒羊的种质特性。     

猪支原体肺炎诊断与处理

猪支原体肺炎是生猪养殖中较为常见的一种猪肺疾病类型,该病具有高度接触性、慢性传染性等特点,如果未能得到及时有效的处理则会扩散至整个生猪群体范围,对生猪养殖的经济效益造成严重损害。且在猪支原体肺炎的发生中,该病经常与圆环病毒及其他病原体进行混合感染,进一步加深生猪病情,对生猪养殖造成非常严重的经济损失。养殖人员在生猪养殖中务必要加强对于猪支原体肺炎的重视程度,积极了解猪支原体肺炎的临床症状与发生特点,采取有效的防治措施以避免猪支原体肺炎发生。该文主要论述猪支原体肺炎的发生特点、临床症状以及诊断防治。     

豌豆蚜生物生态学特性

豌豆蚜(Acyrthosiphon pisum)是许多豆科作物及牧草的重要害虫,不但直接取食寄主植物,造成严重的经济损失,而且还会传播多种植物病毒。豌豆蚜作为生态学研究的模式昆虫,具有复杂的生活周期、多样的生殖方式、表型可塑性以及与细菌复杂的共生关系等诸多特点,已成为众多科学家感兴趣的研究对象。本文全面总结了豌豆蚜生物生态学特性的研究成果,重点综述了豌豆蚜的多型现象和内共生菌研究的最新进展,提出研究豌豆蚜在全球气候和作物种植结构变化下生物生态学特性演变规律的必要性,加强其生态适应性及多型现象等遗传机制研究,以期为建立该虫的可持续防控技术体系提供依据。     

岷县黑裘皮羊肾组织成纤维细胞系的建立及其生物学特性研究

采集岷县黑裘皮羊肾组织,用胰蛋白酶热消化法制备原代细胞,通过差速消化和差速贴壁法进行继代培养和细胞纯化,并对复苏细胞的形态、活力、生长曲线、荧光蛋白质粒转染表达、核型以及乳酸脱氢酶同工酶等生物学特性进行了分析。结果显示:原代和传代细胞生长形态均好,群体倍增时间为28.3 h;染色体2 n=54,二倍体占主体(84%)乳酸脱氢酶同工酶电泳图谱有明显特征,未见LDH4、LDH5谱带,与其它羊有明显区别;外源性荧光蛋白转染质粒在该细胞中能进行复制和表达;细菌、真菌、病毒、支原体检测呈阴性。表明该研究已成功建立岷县黑裘皮羊肾组织成纤维细胞系,为在细胞水平上保存岷县黑裘皮羊种质资源以及进行相关研究提供了理想的生物材料。     

Finishing cattle at pasture at 30 months of age or indoors at 25 months of age: Effects on selected carcass and meat quality characteristics

To examine the effect of a modification of a typically Irish dairy calf-to-beef production system, Charolais × Friesian steers were offered a finishing ration of grass silage ad libitum and 5.6 kg concentrates daily for 174 days prior to slaughter at 25 months of age or grass silage ad libitum for 174 days, followed by pasture for 167 days and slaughter at 30 months of age. Finishing at pasture increased carcass weight (376 vs. 342 kg) but did not affect intra-muscular lipid concentration (28 vs. 24 g/kg). Finishing at pasture decreased Longissimus thoracis et lumborum lightness (35.6 vs. 36.9) and increased shear force of muscle at 2 (8.54 vs 4.32) and 7 days (5.21 vs 3.64 kg) post-mortem but not at 14 days post-mortem (4.45 vs. 3.42 kg). Finishing at pasture did not affect the sensory characteristics of tenderness, juiciness, firmness or chewiness and tended (P < 0.1) to decrease texture and acceptability. It is concluded that modification of this beef production system as described, had minor effects on beef quality which are unlikely to be of commercial significance.     

云南省巧家县石漠化区不同治理措施草地植被特征研究

以天然草地为对照,对云南巧家县尖山社不同治理措施(人工草地、改良草地、封育草地)下石漠化草地的物种组成、群落结构特征、植物种生物多样性和草地植被的年鲜草总产量等进行了比较分析。结果表明:封育草地物种数最多,改良草地次之,人工草地最少。4种草地共有植物种少,不同草地的优势种、亚优势种、伴生种或偶见种不同;人工草地优势种为多年生黑麦草Lolium perenne,改良草地为白三叶Trifolium repens,封育草地为西南委陵菜Potentilla fulgens。4种草地的Simpson多样性指数(D)、Shannon-Wiener多样性指数(H′)和丰富度指数均为封育草地天然草地改良草地人工草地,均匀度为封育草地改良草地天然草地人工草地;产草量和优良牧草比为人工草地改良草地封育草地天然草地;各类草地的产量和品质与其植物多样性指数间存在相反变化趋势;人工草地为最有效石漠化退化草地治理措施,其次是改良草地,封育草地治理效果较差。     

野生动物非法交易犯罪案件信息特征分析

对野生动物非法交易案件进行信息特征分析,可以把握案件的发生规律,提供决策者参考,以便有针对性预防和打击犯罪,更好地保护野生动物资源。本研究应用大数据分析的方法,对野生动物非法交易犯罪案件的文本数据进行结构化处理,建立了word2vec模型。从犯罪因素的角度统计分析了本类案件的信息特征,包括侵害人的特征、作案行为特征、侵害的动物或动物制品、侵害的时间和案件发生的地点等。在梳理基本特征的基础上应用关联算法构建了关联规则。根据特征分析和关联规则,提出了开展季节性防控、对特定群体和场所进行有针对性预防、对上游下游犯罪进行联动打击、与网管等多部门合作,运用现代科技成果进行打击和防范的对策建议。     

Growth performance and carcass quality are not different between pigs fed diets containing cold-fermented low-oil DDGS and pigs fed conventional DDGS,but pelleting improves gain to feed ratio regardless of source of DDGS

The objective of this study was to test the hypothesis that growth performance and carcass characteristics of pigs fed diets containing cold-fermented, low oil distillers dried grains with solubles (DDGS) is not different from that of pigs fed diets containing conventional DDGS regardless of the physical form of the diets. A total of 160 barrows and gilts were used. There were 4 diets, 10 pens per diet, and 4 pigs per pen. Pigs were weaned at 21 d of age and fed a common phase 1 diet that did not contain DDGS during the initial 7 d post-weaning. Pigs were then allotted to the four diets that were arranged in a 2 × 2 factorial design with two sources of DDGS (cold-fermented and conventional DDGS) and two diet forms (meal and pellets). Pigs were fed phase 2 diets from day 7 to 21 and phase 3 diets from day 21 to 43 post-weaning. All diets were based on corn and soybean meal, but phase 2 diets also contained 15% DDGS and phase 3 diets contained 30% DDGS. From day 43, pigs were fed grower diets for 38 d, early finisher diets for 38 d, and late finisher diets for 18 d and these diets also contained 30% DDGS. Feed was provided on an ad libitum basis and daily feed allotments were recorded. Pigs were weighed at the beginning of each phase and at the conclusion of the experiment. On the last day of the experiment, the pig in each pen with a body weight that was closest to the pen average was slaughtered and carcass measurements were determined. Combined results for the two nursery phases indicated that feeding meal diets instead of pelleted diets increased (P < 0.001) average daily feed intake and decreased (P < 0.05) gain to feed ratio (G:F). However, no differences between the two sources of DDGS were observed for the overall growth performance of weanling pigs. For the entire growing-finishing period, the source of DDGS did not affect growth performance, but pigs fed meal diets had reduced (P < 0.001) G:F compared with pigs fed the pelleted diets. There were no differences between the two sources of DDGS for carcass characteristics. Back fat was greater (P < 0.05) for pigs fed pelleted diets than for pigs fed meal diets. In conclusion, no differences in growth performance or carcass characteristics between pigs fed cold-fermented DDGS and pigs fed conventional DDGS were observed. However, pigs fed pelleted diets had greater G:F and greater back fat than pigs fed meal diets.     

差不嘎蒿茎叶解剖特征及其与气候因子的关系

差不嘎蒿(Artemisia halodendron)是我国东北部重要的防风固沙植物,本研究利用石蜡切片法观察内蒙古不同地区差不嘎蒿的叶片和茎解剖结构,运用方差分析方法比较不同地区差不嘎蒿解剖结构间的差异性,以逐步回归得出影响解剖数量特征的主导气候因子.结果表明:差不嘎蒿叶为等面叶,表皮细胞为1层,栅栏组织呈环栅型,排...