离体牛小肠细胞对β-胡萝卜素和叶黄素吸收的研究

用分离出的牛小肠细胞分别与含不同浓度的β-胡萝卜素和叶黄素培养液温育,结果小肠粘膜细胞对两种类胡萝卜素的吸收呈浓度依赖性,吸收率稳定,与浓度无关,且吸收不受培养温度的影响,因而推断牛小肠细胞对两种类胡萝卜素的吸收是一种被动扩散机制,培养液中聚环氧乙烷山梨糖醇单月桂酸脂(Tween 20)超过一定浓度则抑制类胡萝卜素进入肠细胞,其中对叶黄素抑制作用最大。     

氯鼠酮钠盐防治布氏田鼠研究

氯鼠酮钠盐是国内近年合成的抗凝血杀鼠剂,用它对草原主要害鼠布氏田鼠作了毒力测定。急性LD_(50)为1.882±0.7537毫克/公斤,回归方程y=2.2476x+4.3826;慢性LD_(50)为0.20±0.0302毫克/公斤,回归方程y=2.4396x+6.7051。用0.004％、0.008％和0.016％氯鼠酮钠盐小麦毒饵作了现场灭鼠试验,其效果分别为75.83±5.90％、70.81±5.96％和98.41±4.62％。用氯鼠酮钠盐防治布氏田鼠一次投饵时宜用浓度为0.01％～0.016％。     

北方寒地引种抗寒苜蓿品种试验

１９９１、１９９２年两年对１０个抗寒苜蓿品种进行了品种比较试验，鉴选出公农一号、草原一号、草原二号、甘农一号、图牧二号６个苜蓿良种。这些品种适应黑龙江垦区的生态条件，抗寒、抗病性强、长势好、产草量高、品质优良，可以在垦区三江平原推广种植。     

火因子对松嫩羊草草原植物多样性的影响

应用三种丰富度指数，四种多样性系数，五种均匀度指数，进行了不同火因子对羊草草原植物多样性影响的研究。结果得出，灰分刺激与去枯作用明显提高了物种均匀度，加热作用则提高了物种丰富度，火烧的综合作用使得物种多样性显著增加，辛普森多样性指数计算的结果与其他 指数的结果截然相反，不适于在此种情况下应用。     

鸡与鸭饲料氨基酸消化率测定值比较

本研究应用排空强饲法及石岐杂公鸡、樱桃谷公鸭分别测定定了5种饲料氨基酸表观消化率和真消化率。结果表明：除玉米氨基酸表观消化率外,其余饲料的大多数氨基酸消化率在鸡和鸭之间都存在着明显差异;在32小时收粪时间里,鸭的内源氨基酸排出量明显比鸡多;内源氨基酸对鸡和鸭的饲料氨基酸真消化率都有影响,影响大小随蛋白质含量高低而异,一般饲料蛋白质含量越低的饲料两者相差越大。而内源氨基酸排出量对鸭饲料,尤其对低蛋白含量饲料的氨基酸真消化率的影响比鸡更明显。     

Evaluation of immunogenicity and protective efficacy of Actinobacillus pleuropneumoniae HB04C(-) mutant lacking a drug resistance marker in the pigs

Previously, we reported the construction and characterization of a genetically defined Actinobacillus pleuropneumoniae (A. pleuropneumoniae) apxIIC gene mutant, HB04C(-), which conferred protection to mice against infection with A. pleuropneumoniae. In this study, we further evaluated HB04C(-) for safety and its ability to elicit protective immunity in pigs. It was demonstrated that a dose of 2 x 10(8) CFU HB04C(-) was safe to the pigs via intranasal or intramuscular injection. Immunization with a dose of 2 x 10(8) HB04C(-) by both intranasal and intramuscular routine could yield equal protective efficacy and elicited significant protection against experiment challenge with homologous or heterologous serotypes of a virulent A. pleuropneumonia. Taken together, HB04C(-) might serve as a promising vaccine candidate against infection with A. pleuropneumoniae.     

苜蓿干草添加剂研究进展

苜蓿干草在高水分打捆贮藏时添加有机酸、胺类化合物和生物制剂等添加剂可以有效地抑制微生物的生长繁殖 ,缩短干燥时间 ,避免低水分牧草在打捆时的叶片脱落 ,是减少调制过程中营养物质的损失 ,保证苜蓿干草质量的有效措施。     

传染性支气管炎弱毒苗黏膜途径免疫对雏鸡气管及哈德氏腺SIgA细胞分布的影响

采用传染性支气管炎弱毒苗对1日龄雏鸡分别进行点眼和滴鼻免疫.取气管和哈德氏腺做石蜡切片,以葡萄球菌A蛋白-辣根过氧化酶(SPA-HRP)免疫组化染色,对气管和哈德氏腺中SIgA细胞的分布、数量变化进行了观察.结果表明:SIgA阳性细胞分布在哈德氏腺的间质中;气管中的SIgA细胞主要分布在黏膜上皮细胞之间和固有层中,局部黏膜上皮形成的隐窝内也分布有SIgA细胞.数量统计分析表明:免疫组的哈德氏腺和气管中SIgA细胞数量显著高于对照组;点眼免疫的SIgA细胞数量比滴鼻免疫的高;加强免疫则使SIgA细胞数量进一步增多.     

犬脓肿诊治体会

犬脓肿是临床常见的外科疾病之一,常因疮面较大,易形成溃疡,又往往因护理不好及周围环境而缠绵不愈,且常有日趋严重之象。犬脓肿多因外伤（创伤、划伤、缰绳勒伤）和注射不消毒或不彻底引起。多发于颈部及四肢上部。     

Efficacy of the immunoblot assay for cysticercosis in pigs and modulated expression of distinct IgM/IgG activities to Taenia solium antigens in experimental infections

A recently invented immunoblot assay for human cysticercosis was evaluated for efficacy in pigs. The test population consists of 45 pigs with parasitologically confirmed cysticercosis, 47 with heterologous infections, 45 SPF or concrete raised control animals. With this group of 137 animals the test performance was 100% sensitive and 100% specific. The antigen-specific responses of immunoglobulin A (IgA), IgG and IgM in four pigs infected with Taenia solium eggs derived from a human were quantified by immunoblot. Antigen-specific activities were observed as early as 1 week postinfection. The first antigen-specific isotypic response was IgM antibodies directed against a glycoprotein at 97 KD (GP97). This activity generally disappeared between the sixth and ninth week postinfection. Between Weeks 5 and 8, IgG activity rose as IgM activity fell. The IgG activity, however, was directed mostly towards GP50 and GP42 antigens. If the same response occurs in people with cysticercosis, identifying specific isotype activity may help to distinguish new infection from old.