在前临床期检测金仓鼠羊痒病淋巴结中病理型朊蛋白PrP（Sc）

12只雌性5周龄金仓鼠腹腔注射50μL羊痒病（SCRAPIE）263K株10%的脑组织匀浆。在临床前期,感染后第2、4、6、8、10、12周和临床末期第20周,金仓鼠被分别处死,取大脑、淋巴组织、脾脏、肾脏、肝脏、心脏和肌肉等组织,进行蛋白质免疫印迹杂交实验检测朊病毒病理型朊蛋白PrPSc。研究结果显示在临床前期,通过改进后的纯化技术,我们能够检测出淋巴组织和脾脏组织中的PrPSc,但是在肾脏、肝脏、心脏和肌肉等组织中仍然没有检测到PrPSc。     

柞蚕蛹血淋巴多酚氧化酶活性影响因素的研究

柞蚕血淋巴中多酚氧化酶活性的大小对柞蚕丝产量有一定影响,并对柞蚕蛹色起着非常重要的作用。本试验采用分光光度计法对柞蚕蛹血淋巴多酚氧化酶活性大小的影响因素进行了研究。结果表明:柞蚕蛹血淋巴多酚氧化酶的最适pH值为5.0;最适温度为25℃;少量的苯基硫脲对其的抑制作用较为明显;不同化合物对多酚氧化酶的活性影响不同,在相同浓度下,氯化钙和氯化镁对柞蚕蛹血淋巴多酚氧化酶的活性有促进作用,其他化合物(EDTA,维生素C和亚硫酸钠等)则表现为抑制作用。     

Acid–Base Parameters and Steroid Concentrations in Pre‐Ovulatory Follicles and Plasma of Lactating Dairy Cows with Spontaneous and Synchronized Oestrus or Follicular Cyst

The study aimed to compare the acid–base balance and steroid concentrations between follicular fluids (FF) of pre‐ovulatory follicles derived from a spontaneous oestrus (SO), synchronized or induced oestrus (IO) and follicular cysts (CYS) and between FF and blood in dairy cows. Forty‐two dairy cows were included in this study. The animals were allocated to three groups: SO (n = 23); IO (n = 11) using GnRH at day 0 and day 9 and PGF₂α at day 7; and animals with CYS (n = 10). The follicular fluids (FF) were aspirated from the cyst/pre‐ovulatory follicles (? ≥ 15 mm) after SO and after second GnRH dose in IO by transvaginal ultrasound‐guided ovum pick‐up technique. Blood samples (BL) were collected in heparinized vacutainer tubes. The oxygen tension (pO2) in FF of IO was higher (p < 0.05) than in SO and CYS groups. There were negative correlations (p < 0.001, r = ?0.89) between FF and blood pO2. The carbon dioxide tension (pCO2) and lactate level in FF of CYS group were higher (p < 0.05) than in SO and IO groups. There were negative correlations (p < 0.01, r = ?0.73) between blood and FF pO2. Oestradiol‐17β concentration in pre‐ovulatory follicles and plasma of the SO group was higher (p < 0.001) than in IO and CYS groups. Progesterone concentration in pre‐ovulatory follicles and plasma of the SO and IO groups was lower (p < 0.01) than in CYS group. Plasma androstenedione concentration in SO and IO groups was higher (p < 0.05) than in CYS group. In conclusion, acid–base parameters, E2 and P4 levels in the follicular fluid of both IO and CYS groups were deviated greatly from the physiological level (disturbances of intrafollicular/intracystic environment), which may affect the quality of both the oocyte and the granulosa cells.     

兔人工授精技术推广的主要问题与对策

兔人工授精技术是以种兔的培育和商品兔的生产为目的而采用的一种既简单而又有效的方法,是进行科学养兔、实现养兔生产现代化的重要手段,推广兔的人工授精技术,是加快兔种改良步伐,充分发挥优良种兔配种作用,促进养兔生产发展的重要技术措施。本文通过实地调研,分析归纳出我国在兔人工授精技术推广工作中存在的问题,并针对这些问题提出了解决办法,同时也对推广兔人工授精技术提出了一些措施和建议。     

猪流感病毒分离株的特性及致病性

为了解猪流感病毒(swine influenza virus,SIV)分离株A/Sw/SH/1/2007(H1N2)的特性,对毒株的抗原位点、受体位点、潜在糖基化位点进行比较分析,并进行雏鸡、小鼠致病性试验.结果表明,A/Sw/SH/1/2007与北美经典株A/Sw/Tennes/1455/1977(H1N1) HA抗原位点最接近,HA1蛋白4个抗原位点中只有Ca位点有2个氨基酸改变,发生抗原变异,Sa、Cb抗原位点均只有1个氨基酸发生改变,不影响其抗原性;受体位点高度保守,只有183位发生改变;A/Sw/SH 1/2007有6个潜在的糖基化位点,在276位丢失了1个潜在的糖基化位点,但同时在274位出现了1个新的糖基化位点.NA蛋白抗原位点序列与广西分离株A/Sw Guangxi/13/2006(H1N2)同源性最高,除401位氨基酸发生G→R改变外,其余抗原位点均保守.耐药性分析显示,该病毒对金刚烷胺、扎那米韦药物均敏感.致病性试验结果表明,A/Sw/SH/1/2007对雏鸡无致病性,ICPI为0;肌注小鼠2周内死亡100％,滴鼻小鼠死亡80％,存活小鼠血凝效价为27,而与经典H1N1亚型SIV毒株只有较低的交叉凝集,HI为2 3.4～3.6.     

猪流感病毒多表位融合蛋白对小鼠的免疫原性分析

作者拟利用表位多肽的抗原性及黏膜佐剂免疫增强作用,设计可通过黏膜途径免疫接种的猪流感病毒通用型疫苗.体外合成H1N1、H3N2亚型猪流感病毒表位抗原基因,C末端串联大肠杆菌热敏性肠毒素LTb基因,构建pET30(a)-ep-LTb表达载体,利用SDS-PAGE、Western blot分析重组融合蛋白表达及生物学特性,小鼠免疫试验分析融合蛋白免疫原性.SDS-PAGE检测表达蛋白相对分子质量约38 ku,主要以包涵体形式存在.重组蛋白可与抗His-tag抗体和CTB抗体发生特异性反应.ELISA及HI试验检测,经黏膜途径免疫的小鼠产生了针对重组表位模拟抗原蛋白及H1N1、H3N2亚型猪流感病毒的血清抗体及局部黏膜分泌型IgA抗体.利用猪流感病毒表位抗原与LTb基因串连获得的融合蛋白具有良好的免疫原性和反应原性,且在黏膜接种局部产生理想的分泌型IgA抗体,能有效阻断病原由黏膜局部感染,为研制猪流感病毒通用型疫苗奠定了基础.     

A comparative study on the rumen microbial populations,hydrolytic enzyme activities and dry matter degradability between different species of ruminant

A comparative study among Korean native cow (Hanwoo), Holstein dairy cow, Korean native goat and crossbred sheep on the population and marker concentration of ruminal microbes, the activities of carboxymethylcellulase (CMCase), xylanase and amylase, and in situ dry matter (DM) degradability were conducted. Twelve ruminally cannulated animals, three of each species, were used. Animals were fed the same diet containing 40% formula feed and 60% rice straw at the level of 2.5% of body weight. Total viable microbial populations in the rumen fluid were significantly (P < 0.01) greater for bacteria and fungi in goat than those of Holstein. The protozoan population among ruminant species was the reverse from that of bacteria. The concentrations of 2,6‐diaminopimelic acid and chitin as markers for bacteria and fungi in the rumen fluid, respectively, were highest in goat, which is in accordance with the above population data. The concentration of aminoethylphosphonic acid as marker of protozoa was highest in Hanwoo and lowest in sheep (P < 0.01). Goat had the highest (P < 0.01) activities of all the enzymes investigated among ruminants. In situ effective degradation of the DM of rice straw was approximately 19% higher in the rumen of goat compared with other animals.     

鸭多巴胺受体D1基因CDS区多态性与生长性状的关联性分析简

本研究采用PCR-SSCP法与DNA直接测序技术相结合对兴义鸭和樱桃谷鸭多巴胺受体D1 (dopamine receptor D1,DRD1)基因编码序列(coding sequence,CDS)区130－587 bp区域的多态性进行检测,并分析其多态性对樱桃谷鸭生长性状的影响。结果表明,在樱桃谷鸭和兴义鸭DRD1基因编码区130－587 bp区域内均检测到3种基因型：AA、BB和AB,2个等位基因：A和B;AA基因型均为优势基因型,频率分别为0.7416和0.5643,等位基因A均为优势等位基因,频率分别是0.8539和0.7204;多态信息含量分别为0.2184和0.3217,分别处于低度多态和中度多态位点,樱桃谷鸭群体中该座位基因型分布处于Hardy-Weinberg平衡（P>0.05）,兴义鸭群体则偏离了Hardy-Weinberg平衡（P<0.05）;序列比对发现2个SNPs位点,其中c.189 T＞C为同义突变,c.507 T＞A为错义突变,导致丝氨酸（S）变成精氨酸（R）。关联分析结果显示,BB基因型樱桃谷鸭个体的8周龄重和12周龄体斜长显著高于AB基因型（P<0.05）,10周龄重、12周龄重和12周龄胸深显著高于AA和AB基因型（P<0.05）。研究结果揭示该多态座位可能是影响鸭生长性状的一个标记辅助选择位点。     

成年母牛体况评分及其影响因素分析

体况评分(BCS)是评价奶牛饲养效果好坏、营养代谢正常与否的标志,也是奶牛健康与否的标志之一。体况评分为制订下一阶段的饲养管理措施提供重要依据,同时也受到很多因素的影响。本文旨在研究不同胎次、干奶期、泌乳期、不同的泌乳阶段等影响因素对奶牛体况评分的影响。测定本场2009年3月共219头胎次在0～6胎的中国荷斯坦奶牛体况评分,应用SPSS15.0软件对不同胎次、干奶期、泌乳期、不同的泌乳阶段等影响因素对奶牛体况评分的影响加以分析。结果表明:胎次对奶牛BCS的影响不显著(p0.05);干奶期和泌乳期对奶牛BCS的影响极显著(p0.01);泌乳阶段对BCS的影响极显著(p0.01)。因此提示在实际的生产中应灵活调控各影响因素对体况评分的影响,提高母牛生产性能。