狂犬病病毒CVS-11株的培养及其效价测定

本研究通过神经瘤细胞（NA）培养CVS-11株狂犬病病毒,并测定不同批次的病毒毒价,为优化狂犬病疫苗的生产工艺提供数据支持,具有实际意义。病毒培养和检测结果表明,第1次和第2次收获的病毒液病毒含量较高,在107.0FFU/0.1 mL以上,毒力为106.4～107.0LD50/0.03 mL;而第3次收获的病毒含量则较低,只有106.0FFU/0.1 mL左右,毒力为105.0～105.3LD50/0.03 mL。第1次和第2次收获的病毒液可用于制备狂犬疫苗,第3次收获的病毒液因毒价较低不适于制备狂犬疫苗。     

关注雏鸭钴缺乏症

微量元素钴是维生素B12的组成元素,在鸭的体内参与代谢,能激活磷酸酶、精氨酸酶、过氧化氢酶;抑制细胞色素氧化酶、琥珀酸脱氢酶的活性;改善基础代谢以及糖和氮的吸收;参与维生素A、B、C、D的合成;在血液和骨髓形成过程中起重要作用。当摄入不足时,会使丙酸不能发生正常的代谢,出现神经障碍、贫血、拉稀、食欲减退、营养不良,导致死亡和产蛋下降。因此,饲养中要关注雏鸭的钴缺乏症,主要应注意以下几点：     

甜柿果实发育过程中单宁的积累

据《Scientia Horticulturae》的一篇研究报道（http：／／dx．doi．org／10．1016／j．scienta）,来自巴西圣保罗大学的研究人员研究了“Giombo”和“Fuyu”甜柿果实发育过程中单宁物质的积累。单宁是引起柿果涩味的主要原因。研究人员比较了“Giombo”和“Fuyu”甜柿从果实发育期至成熟阶段的差异,以明确两个品种的涩味程度是否与单宁的早期积累、细胞分化阶段单宁的积累模式、细胞密度、总单宁含量及可溶性单宁含量有关。     

家禽对三种重要金属微量元素的需要量及其添加

1铁 机体内60％～70％的铁存在于血红素中,20％左右的铁和蛋白质结合形成铁蛋白,贮存在肝、脾、骨骼及其他组织中。铁缺少时,雏鸡易患小红细胞色素过少性贫血。铁还与羽毛颜色形成有关,缺铁严重时羽毛完全退色。由于缺铁可导致脂蛋白醋酶活性降低,因而血中甘油三酯浓度上升,继发高血脂症。     

饲料中氰化物含量的分析

氰化物系指含氰基的化合物,植物中的氰化物是以甙形式存在的氢氰酸有机衍生物,即氰甙。氰甙本身无毒性,但当其水解释放出游离的氰化氢后,就会引起动物中毒。富含氰甙的植物有青饲料木薯、高粱和玉米的幼苗、亚麻、络麻、海南刀豆、狗爪豆以及蔷薇科植物的叶子和种子。其中毒机理是一种非特异性的酶抑制剂,能抑制细胞内多种含金属离子的酶系统,如细胞色素氧化酶、过氧化氢酶、接触酶、琥珀酸脱氢酶、乳酸脱氢酶等。氢氰酸中毒发病迅速,当动物过食含氰甙的饲料15~20分钟,即可发生中毒现象。中毒家畜表现为呼吸困难、呕吐、流涎、肌肉痉挛,可视黏膜鲜红色。剖检血液鲜红色,胃肠有出血性炎症。     

孔雀马立克氏病的流行症状与诊疗

由疱疹病毒科中的马立克氏病疱疹病毒引起的最常见的禽恶性肿瘤病（癌）。以淋巴细胞组织增生,在各内脏器官以及外周神经、肌肉、中产生单核细胞浸润和肿瘤为特征。有传染性,能导致感染禽大批死亡,是养禽业的很大威胁。此病由匈牙利兽医病理学家J.马立克于1907年首先发现,并用他的姓氏命名。最初的流行呈慢性经过,病变也以外周神经的淋巴细胞增生为主,死亡率不高。     

Effect of diacylglycerol acyltransferase 2overexpression in 3T3-L1 is associated to an increase in mono-unsaturated fatty acid accumulation

Background：Fatty acid（FA） composition is the most important parameter affecting the flavor and nutritional value of the meat.The final and the only committed step in the biosynthesis of triglycerides is catalyzed by diacylglycerol acyltransferase 2（DGAT2）.The role of DGAT2 in lipid accumulation has been demonstrated in adipocytes,However,little is known about the effect of DGAT2 on the FA composition of these cells.Methods：To investigate the role of DGAT2 in regulating lipid accumulation,FA composition and the expression of adipogenic genes,we cloned the open reading frame of the porcine DGAT2 gene and established 3T3-L1 cells that overexpressed DGAT2.Cells were then cultured in differentiation medium（DM） without FA,with a mixture of FAs（FA-DM）,or containing a ~（13）C stable isotope-labeled FA mixture（IFA-DM）.The FA composition of adipocytes was analyzed by gas chromatography-mass spectrometry and gas chromatography-isotope ratio mass spectrometry.Quantitative PCR and western blotting were employed to detect expression of adipogenic genes in 3T3-L1 adipocytes cultured with FA-DM for 12 d.Results：The triacylglyceride（TAG） content was significantly higher in 3T3-L1 adipocytes overexpressing DGAT2 than in control cells.When cultured in DM or FA-DM for 12 d,cells overexpressing DGAT2 showed a higher proportion of unsaturated FAs（C16：1 and C18：1）.However,when cells overexpressing DGAT2 were cultured with FA-DM for30 min,the FA composition was almost identical to that of controls.Further,the proportion of stable isotope-labeled FAs were similar in 3T3-L1 adipocytes overexpressing DGAT2 and control cells cultured in IFA-DM for 12 d.These results collectively indicate that the higher proportion of mono-unsaturated FAs,C16：1 and C18：1,may originate from de novo FA synthesis but not from the uptake of specific FAs from the medium.This hypothesis is further supported by evidence that both mRNA and protein expression of genes involved in FA synthesis（ACACA,FASN,SCD1,and A-FABP?     

Escherichia coli challenge and one type of smectite alter intestinal barrier of pigs

An experiment was conducted to determine how an E. coil challenge and dietary clays affect the intestinal barrier of pigs. Two groups of 32 pigs （initial BW： 6.9 ± 1.0 kg） were distributed in a 2 x 4 factorial arrangement of a randomized complete block design （2 challenge treatments： sham or E. coil, and 4 dietary treatments： control, 0.3% smectite A, 0.3% smectite B and 0.3% zeolite）, with 8 replicates total. Diarrhea score, growth performance, goblet cell size and number, bacterial translocation from intestinal lumen to lymph nodes, intestinal morphology, and relative amounts of sulfo and sialo mucins were measured. The E. coli challenge reduced performance, increased goblet cell size and number in the ileum, increased bacterial translocation from the intestinal lumen to the lymph nodes, and increased ileal crypt depth. One of the clays （smectite A） tended to increase goblet cell size in ileum, which may indicate enhanced protection. In conclusion, E. coli infection degrades intestinal barrier integrity but smectite A may enhance it.     

提高山羊痘活疫苗绵羊羔睾丸细胞产量的综合措施

羊痘（Capripox）又名羊“天花”,是由山羊痘病毒属（Capripoxvirus,CPV）的痘病毒引起的羊的一种急性、热性、接触性传染病,包括绵羊痘（Sheeppox,SP）和山羊痘（Goatpox,GP）。主要表现为发热,无毛或少毛部位的皮肤或黏膜发生丘疹和疱疹。     

三倍体方正银鲫(古)同二倍体红鲫(早)杂交胚胎的非整倍体发育

根据囊胚细胞和原肠胚细胞染色体数的观察，三倍体雄性方正银鲫Carassius auratus gihelio)和二倍体雌性红鲫(Carssius auratus red variety)杂交获得的胚胎，是杂合的非整倍体胚胎，因此胚胎发育畸形，中途死亡。胚胎染色体数从50142，变异幅度很宽，86％以上胚胎细胞染色体数分布在56-105范围内，其中以染色体数为76—86的胚胎细胞最常见，占34％。