Seroepidemiological survey of Corynebacterium pseudotuberculosis infection in sheep in Japan using enzyme-linked immunosorbent assay and immunodiffusion

Sera from 1186 apparently healthy sheep in Hokkaido were examined by enzyme-linked immunosorbent assay (ELISA) and immunodiffusion (ID) for the presence of antibodies against Corynebacterium pseudotuberculosis. ELISA-positives were 466 (39.3%) while ID-positives were 330 (27.8%). Spread of caseous lymphadenitis in sheep in Hokkaido was thus clarified. Although ID was less sensitive than ELISA in detecting the antibodies against C. pseudotuberculosis it did not give any non-specific reaction. From the results and in view of the simplicity of the test procedure, ID was found to be of practical diagnostic value. Distribution by age group of anti-C. pseudotuberculosis antibodies in 758 sheep in a herd detected by both tests showed that the ratio of positives was low in sheep aged less than 1 year, and the ratio increased significantly in those aged 1 year and continued to increase with age until it reached a plateau at the age of 4-5 years.     

Computer image analysis of intramuscular adipocytes and marbling in the longissimus muscle of cattle

The deposition of fat in muscle, recognized by the consumer as marbling, is an important meat quality trait. The objective of the study was to provide additional insights into the quantitative extent of marbling by means of computer image analysis. Fifty-one F(2) generation German Holstein and Charolais crossbreed cattle, 18 mo of age, were used to determine relationships among marbling traits, adipocyte size, and the amount of adipose tissue in different depots. Differences were recorded among the size of i.m. adipocytes in different groups of marbling flecks, divided according to the location in the muscle cross-section and to the size of the marbling flecks. The results showed positive correlation between i.m. adipocyte size and the weight of s.c. fat, intestinal fat, omental fat, and perirenal fat (r = 0.50, 0.61, 0.70, and 0.63, respectively, P < 0.001). The i.m. adipocyte size was correlated with i.m. fat content, number of marbling flecks, proportion of marbling fleck area, and total length of marbling flecks (r = 0.71, 0.44, 0.62, and 0.55, respectively, P < 0.01). The number of marbling flecks was also correlated with i.m. fat content, proportion of marbling fleck area, and total length of marbling flecks (r = 0.58, 0.62, and 0.91, P < 0.01, respectively). The ventral marbling flecks had a 5-fold larger fleck area, 4-fold more adipocytes, and larger adipocytes (P < 0.001). Larger marbling flecks contained larger adipocytes (P < 0.001). Moreover, compared with the small marbling flecks, there was a 48-fold larger fleck area and 26-fold more adipocytes in the large marbling flecks. The results indicate that i.m. fat deposition increases concurrently with the other fat depots but is still independent. Furthermore, the i.m. fat is preferentially deposited in the ventral area of LM. Although the i.m. adipocyte size has an important effect on the traits of marbling flecks, cell number plays a greater role in i.m. fat deposition than cell size.     

基于信息熵的天山山区降水时空变化特征

降水是山区气候中最重要的气象要素之一,其大小及变化直接关系到干旱山区中、下游的生态环境与经济社会的发展,但是,由于技术和地理条件的限制,是难以精确观测的气象要素。本研究采用天山山区31个台站和1960-2008年间的实测降水资料,应用信息熵方法对天山山区年、季和月的降水变化特征进行分析。结果表明,天山山区降水在时间和空间上均存在变异性,时间变异性表现为信息熵的无序指数(DI)年际变化小于季节变化,季节变化小于月变化。DI多年变化特征呈现下降趋势;冬季DI变化最为显著,夏季最小;冬季北坡降水随高程的增加DI变化呈显著增加趋势(P0.05),春、夏和秋季南坡降水随高程的增加DI变化呈显著减少趋势(P0.05)。山区月降水4-9月逐渐增加,10月至次年3月降水逐渐减少,月降水DI的变化与降水变化呈反相特征。在空间上DI变化与降水的分布相反,表现为南强北弱,东强西弱,伊犁河谷降水DI变化最小。结果证明,DI方法能够有效地分析山区降水的时空变化特征,为合理开发山区的水资源提供科学依据。     

兰州地区胡麻田杂草消长动态及群落生态位研究

采用田间调查和室内测定、相对丰度和生态位计算与分析相结合的方法,对兰州地区胡麻田杂草群落进行了研究。初步明确了兰州地区胡麻田间杂草种类共有11科23种,其中主要科为:禾本科、菊科、藜科、苋科和旋花科;优势种群为:地肤、狗尾草、藜、苣荬菜、稗草和打碗花。同时明确了优势杂草的消长变化规律,即4月中旬为杂草始发期,5月中旬和6月中旬为2个出草高峰期。优势杂草生态位的研究结果表明,地肤的综合生态位宽度值最大,对胡麻的危害最大,其次为狗尾草和藜;地肤与狗尾草的时间生态位重叠值最大,与苣荬菜的水平生态位重叠值最大;而苣荬菜和藜的垂直生态位重叠值最大,它们相互之间利用资源的相似性较高。利用相对丰度和生态位宽度均能确定优势杂草的种类,反映杂草对作物危害程度的大小。     

蜂胶的作用及其在猪生产中的应用

本文主要介绍了蜂胶的作用及其在猪生产中的应用。     

气相色谱/质谱法测定饲料中三唑仑的含量

本实验建立了检测饲料中三唑仑的气相色谱/质谱法。样品经有机溶剂提取,阳离子固相萃取小柱净化后注入气相色谱质谱仪进行测定,并且经质谱确证。结果表明,三唑仑在0.1～5.0μg/mL范围内具有良好的线性关系,方法的回收率、精密度较高。     

云南省泸水市非洲猪瘟疫情流行病学调查

2019年2月,云南省怒江傈僳族自治州泸水市发生非洲猪瘟疫情。农业农村部和云南省农业农村厅联合督导组对此起疫情进行了流行病学调查和扩散风险分析。调查分析显示:泔水喂猪引发此起疫情的可能性最大,当地再次发生非洲猪瘟疫情的风险较高,但疫情扩散到疫点之外和野猪的风险较小。督导组由此提出,明确各相关部门防疫责任,继续加大疫情监测和排查力度,加大对餐厨剩余物和猪肉销售点废弃碎肉的监管,禁止泔水喂猪,进一步提升猪场的猪病防控能力。此起疫情对非洲猪瘟防控具有指导意义,对边远贫困地区扶贫攻坚工作和边境动物卫生安全有一定的警示作用。     

非洲猪瘟疫情形势下生长育肥猪饲养管理关键技术

育肥猪的科学饲养与管理直接影响猪场经济效益,非洲猪瘟疫情形势下的育肥猪生产更是充满挑战与压力。文章旨在针对生长育肥猪养殖的基本环节及操作要点,从环境控制、科学饲养与管理、严格防疫等方面阐述了育肥猪养殖的关键技术,为非洲猪瘟疫情防控形势下的生猪保供复产提供技术支撑。     

环糊精包合氟苯尼考在猪体内的药代动力学研究

为评价采用新包被工艺生产的氟苯尼考（受试制剂F）与国外同类产品（R1）、国内同类产品（R2）在猪体内的生物等效性并探索其药代动力学特性,本试验采用随机三制剂、三周期自身交叉试验设计,选取6头健康的阉割小公猪（体重15 kg±2 kg）,分别灌胃给药3种制剂,给药剂量为20 mg/（kg·BW）,采用高效液相色谱法测定血浆中氟苯尼考浓度,利用Kinetica 5.0软件分析药代动力学特性,SAS统计软件进行生物等效性评价。结果显示,受试制剂在猪体内的药时曲线符合带时滞的一级吸收一室开放模型,F、R1、R2的峰浓度（C_max）分别为16.0845、18.3287和21.1678 μg/mL,药物达峰时间（T_max）分别为5.0、1.9、1.5 h;药-时曲线下面积_（0-∞）（AUC_0-∞）分别为144.7327、118.2670和123.3715 μg/mL·h;受试制剂相比于两种参比制剂的相对生物利用度分别为122.51%（R1）和117.52%（R2）。结果表明,环糊精包被氟苯尼考有更好的缓释作用,具有更好的生物安全性,药效维持时间长,生物利用度有效提高。