Changes in growth performance, digestive enzyme activities and nutrient digestibility of cherry valley ducks in response to aflatoxin B1 levels

The objective of this study was to investigate toxic effects of aflatoxin B1(AFB₁) on growth performance, organs, hepatic enzyme activities, apparent digestibility of nutrients and digestive enzyme activities in ducks. Ninety 1-day-old Cherry Valley commercial ducks were designed to three treatment groups with three replicates of ten birds each. Group I (control) was fed conventional feed free of AFB₁, group II or III was fed the diets containing 20 μg/kg or 40 μg/kg AFB₁-contaminated rice respectively. The feeding trial lasted 6 weeks. The results were that decreased body weight gain and feed intake, increased feed to gain ratio and selected organ weights (liver, kidney and pancreas) were observed in AFB₁-treated groups. The activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly increased in AFB₁-contamined groups. The apparent digestibility of crude protein (CP) was significantly lower while activities of digestive enzyme from duodenum contents including protease, chymotrypsin, trypsin and amylase were increased in AFB₁-treated group. These results indicated that AFB₁ of feed could decrease growth performance and apparent digestibility of nutrients, change digestive enzyme activities of duodenum contents in duck.     

山东省沂南县动物强制免疫“先打后补”现状分析

2021年,沂南县推进动物疫病强制免疫“先打后补”工作,依托“鲁牧云”信息平台,通过强化组织领导,加强政策宣贯,强化人员培训,放开强免疫苗经营渠道,提供抗体检测无偿服务等措施,提升了养殖场户“先打后补”的积极性、自主性、灵活性,强化了养殖场户动物防疫主体责任,满足了养殖场户疫苗多样化需求。但由于 “先打后补”补助金额少、社会化服务不规范、基层动物防疫体系弱化、缺少配套工作经费等原因,部分养殖场户实施“先打后补”的积极性不高。建议通过规范社会化服务组织,强化培训水平,提高补助标准,强化三级（县乡村）基础设施建设,升级“鲁牧云”等措施,确保“先打后补”政策惠及更多养殖场户。     

2型猪链球菌的血清学鉴定

本试验首次证实了２型猪链球菌在我国的存在，采用玻片凝集、琼脂扩散及毛细管沉淀等３项试验，对１９９０年以来广东某猪场断奶仔猪暴发流行的败血症、脑膜炎及关节炎病猪中分离的１５株链球菌进行了血清学鉴定。结果表明：１５株链球菌均为２型猪链球菌；用高压法提取抗原进行沉淀反应，其结果比酸热法提取抗原具有简便、敏感、特异性强的特点。     

家蚕微粒子病的PCR诊断技术研究

在ＤＮＡ水平上，以聚合酶链反应（ＰｏｌｙｍｅｒａｓｅＣｈａｉｎＲｅａｃｔｏｎ，ＰＣＲ）技术检测家蚕微孢子虫的结果。设计、合成了两对引物，其中引物Ⅰ是针对家蚕微泡子虫（ＮｏｓｅｍａｂｏｍｂｙｃｉｓＮ．ｂ．）引物Ⅱ是针对变形孢子虫（ＶａｉｒｉｍｏｒｐｈａｎｅｃａｔｒｉｘＶ．ｎ，）的。用这两对引物分别对“桑尺蠖微孢子虫”孢子ＤＮＡ和Ｎ．ｂ．（镇江株）的纯孢子及其感染的幼虫、蛹及蛾的ＤＮＡ进行ＰＣＲ扩增，均获得预期的阳性条带；对不同引物扩增的产物进行了ＤＮＡ序列分析。初步认为引物Ⅰ可作为家蚕微孢子虫Ｎ．ｂ．特异性较高的检测引物，而引物１是微孢子虫共有的检测引物。进一步讨论了对家蚕微孢子的检测及分类上的问题。     

青藏高原几种嵩草的生物量及其幼苗生长发育的初步研究

研究了青藏高原４种嵩草属植物的枝条发育状况，生物量积累特征以及３种嵩草幼苗的生长发良规律。结果表明；各嵩草营养枝条的季节变化有两个高峰期，而线叶蒿草的生殖枝有一个明显的高峰期，其它嵩草无高期峰。     

对处理一起市场上投诉的黄膘猪肉的体会

1事件回顾
　　2010年7月某日,某市某农贸市场有肉商向市场管理部门投诉,称其雇人在该市某县屠宰厂屠宰的猪为黄膘猪,请市场管理部门协助处理,并把猪胴体、内脏丢弃在市场管理办公室前的地上,引来群众围观。市场管理方当即向辖区的城区政府汇报;也有群众分别致电当地媒体和市政府热线,政府热线要求市水产畜牧兽医局处理,市水产畜牧兽医局安排市动物卫生监督所派员处理。     

Characterization of porcine circovirus type 2 (PCV2) infection in swine lymphocytes using mitogen-stimulated peripheral blood lymphocytes from healthy PCV2-carrier pigs

Information regarding the susceptibility of swine lymphocytes to PCV2 is rather limited. To further explore and characterize the PCV2 infection in swine lymphocytes, an in vitro model using concanavalin A (Con A)-stimulated peripheral blood lymphocytes (PBLs) obtained from clinically healthy PCV2-carrier pigs was introduced. It was found that the PCV2 antigen-containing rate was below 2% in PBLs from healthy PCV2-free pigs following treated simultaneously with Con A and PCV2. However, significantly higher PCV2 antigen- and nucleic acid-containing rates could be seen in Con A-stimulated PBLs from clinically healthy PCV2-carrier pigs. Prior to Con A treatment, both of the PCV2 antigen- and nucleic acid-containing rates in PBLs from healthy PCV2-carrier pigs were less than 1%; however, they reached 22.1+/-5.7% by flow cytometry and 27.1+/-6.5% by in situ hybridization, respectively, at 4-day post-incubation with Con A. Phenotyping of PCV2 antigen-containing cells revealed that PCV2-positive cells could be detected in both T and B lymphocyte populations within which IgM-positive B lymphocytes appeared to have a relatively higher positive rate. The Con A-stimulated PBLs also displayed a significantly higher viral load by the measurement of either PCV2 DNA copy number or viral titer when compared with the non-treated PBLs from healthy PCV2-carrier pigs. The results indicate that PBLs, especially IgM-bearing B lymphocytes, are indeed susceptible to PCV2 infection and PCV2 is capable of replicating in dividing lymphocytes. This activation-induced replication may explain in part the pathogenesis of lymphoid depletion in PMWS-affected pigs.     

长爪沙鼠生长与繁殖性能的主要指标测定

目的:探讨在普通级环境下饲养的长爪沙鼠的饲养管理、生长发育及繁殖等情况。方法:观测长爪沙鼠的饲养管理方法,记录0-12周的生长发育情况,统计1～5胎的初生个体重、窝产仔数、窝重和离乳重,测定成年长爪沙鼠主要脏器的重量、脏器重量/体重的比值。结果表明:在普通级环境下饲养的长爪沙鼠初生体重为2.8～3.2g,窝产仔4～9只,3～8周龄体重增长快,5周龄开始雌雄体重有显著性差异(P<0.05)繁殖性能好。     

苜蓿皂甙对蛋鸡生产性能、屠体指标、胆固醇及血清脂质的影响

试验选用288只400日龄海兰褐商品蛋鸡,随机分为4个处理,每组72只鸡,设4个重复,每个重复18只鸡,采用单因素方差设计。在玉米-豆粕型日粮基础上添加0、30、60、90mg/kg的苜蓿皂甙进行60d的饲养试验,研究苜蓿皂甙对蛋鸡生产性能、屠体指标、胆固醇及血清脂质的影响。结果表明:日粮中添加苜蓿皂甙对产蛋率、平均蛋重、耗料量和料蛋比没有显著影响(P>0.05);60mg/kg和90mg/kg苜蓿皂甙能够显著降低腹脂率(P<0.05),60mg/kg能够提高半胫膛率(P<0.05)和降低肝脏胆固醇浓度(P<0.05)。添加组血清中总胆固醇极显著降低(P<0.01),60mg/kg和90mg/kg苜蓿皂甙组甘油三酯和低密度脂蛋白质显著降低(P<0.05),高密度脂蛋白有所提高(P>0.05)。综合分析得出,日粮中添加60mg/kg的苜蓿皂甙效果最佳。     

Seroprevalence of chlamydial infection in dairy cattle in Guangzhou, southern China

Chlamydia spp. are obligate intracellular gram-negative bacteria that cause a wide range of significant diseases in humans and animals worldwide, resulting in significant economic losses. Chlamydial infection in cattle has been reported in many countries including China. However, there has been no survey of chlamydial infection of dairy cattle in Guangzhou, southern China. The objective of the present investigation was to examine the chlamydial seroprevalence in dairy cattle in Guangzhou, subtropical southern China by using an indirect hemagglutination assay (IHA). The overall seroprevalence of chlamydial infection in dairy cattle was 7.25% (29/400). Greater than or equal to eight-yr-old dairy cattle had the highest seroprevalence (10.34%), followed by those that were ≥ 6 years old or < 7 years old dairy cattle (10.20%), although there were no statistically significant differences among different groups (P > 0.05). Dairy cattle with 5 pregnancies had the highest seroprevalence (10.81%). These results indicate that chlamydial infection was present in dairy cattle in Guangzhou, subtropical southern China, and integrated strategies and measures should be executed to control and prevent chlamydial infection and disease outbreak in the study region.