湖北省某县羊布鲁氏菌病群体血清流行率横断面研究

2015年初,湖北省某县启动羊布鲁氏菌病监测净化工作。为了解该县羊布鲁氏菌病的流行现状和阳性场户的地理分布,对该县1 567户养羊场户分两阶段抽样,采用虎红平板凝集和c ELISA垂直试验进行检测,获知该县羊布鲁氏菌病的群体血清流行率。结果显示:该县羊布鲁氏菌病真实群体血清流行率为2.00%,不同乡镇和不同养殖规模养羊场户的群体血清流行率分别在0~11.16%和0.67%~25.58%之间不等;检出布鲁氏菌病阳性场户74户,其分布在全县10个乡镇,主要集中在4个乡镇,以存栏量在50只以下的养羊场户居多;不同乡镇和不同养殖规模养羊场户中的布鲁氏菌病分布情况不同。调查结果提示,应根据本底调查结果,制订净化方案,实行布鲁氏菌病区域化管理,同时加强对不同流行区域间羊群移动的检疫监管。     

中药"增免散"对鸡腔上囊细胞凋亡和外周血T细胞亚群的影响

将300只1日龄雏鸡随机分成正常对照组、中药“增免散”组、环磷酰胺组、环磷酰胺组 左旋咪唑组、环磷酰胺 “增免散”组,6日龄用鸡新城疫(ND)La Sota疫苗免疫点眼滴鼻,14、21、28、35日龄测定鸡血液ND抗体效价、外周血液CD4 、CD8 T淋巴细胞浓度、腔上囊器官指数、腔上囊细胞凋亡率,探索中药“增免散”的免疫增强机理。结果表明:中药“增免散”不但能提高外周血液中CD4 /CD8 T淋巴细胞百分比,促进鸡腔上囊的生长发育,降低腔上囊细胞凋亡率,而且对环磷酰胺的免疫抑制有部分拮抗作用。     

HACCP在酸奶生产中的应用

HACCP即“危害分析和关键控制点”,是Hazard Analysis Critical Contril Point英文的首字母缩写。运用HACCP体系可以防患于未然,对于可能发生的问题便于采取预防措施,通过此体系来减低,甚至防止各类食品污染(包括生物性、化学性和物理性三方面)。实施HACCP体系可以根据实际情况采取简单、直观、可操作性强的检验方法,如外观、温度和时间等进行控制。     

山羊卵母细胞体成熟培养条件的研究

从山羊屠宰场收取卵母细胞，置于39％、5％CO2的培养箱中，作24小时体外成熟培养。在含10％犊牛血清(FCS)的成熟培养液里分别添加0％、20％~N卵泡液，试验结果表明，成熟卵母细胞率分别为54．5％、66．7％，差异不显著。在成熟培养液里添加不同血清，即10％犊牛血清(FCS)和羊血清(NGS)，试验结果表明，成熟卵母细胞率分别为54．5％、65.4％，差异不显著。     

饲料用玉米加工中的HACCP体系的建立与应用

饲料的安全性直接影响到动物产品的质量安全。依据国际先进的HACCP质量管理体系,对饲料用玉米加工过程中主要危害因素进行分析,确定出原料接收、原料贮藏、原料清理、原料研磨、添加剂、包装环节为关键控制点(CCP),并提出相应的控制措施,可以有效控制饲料用玉米安全性和产品质量,减少产品的安全风险,为饲料用玉米质量安全控制提供借鉴。     

Prevalence and risk factors associated with intestinal parasites in pigs in Chongqing, China

From 2007 to 2009, the prevalence of intestinal parasites was investigated in intensive and extensive pig farms in Chongqing, China. A total of 2971 samples from both sexes and five age categories (breeding boars, breeding sows, fatteners, growers and weaners) were evaluated by standard methods for the presence of helminth ova and protozoan oocysts, cysts and/or trophozoites. Of the 2971 pigs sampled, 362(12.18%) were infected with Ascaris suum, 301(10.13%) with Trichuris suis, 301(10.13%) with Oesophagostomum spp., 491(16.53%) with Eimeria spp., 149(5.02%) with Isopora suis, 677(22.79%) with Balantidium coli and 196(6.60%) with Cryptosporidium spp. Growers had the highest infection rate while breeding boars had the lowest among the five age categories. B. coli was the most common protozoan in all pig age groups. Pigs infected with multiple parasites were common. Risk factors such as management methods, seasons, ages, etc. can influence the infection rate to a certain degree. This investigation provides relevant data about risk factors for pig farmers, thus allowing them to make more appropriate antiparasitic treatments according to farm conditions and local climate in Chongqing.     

Prevalence and age-related variation of Cryptosporidium species and genotypes in dairy calves

Fifteen dairy farms in seven states on the east coast of the US were each visited on two consecutive years to determinate the prevalence of Cryptosporidium species in pre-weaned (5 days to 2 months) and post-weaned calves (3-11 months), respectively. After each of 971 fecal specimens collected directly from each calf was sieved and subjected to density gradient centrifugation to remove debris and concentrate oocysts, specimens were examined by immunofluorescence microscopy, and polymerase chain reaction (PCR). For all PCR-positive specimens the 18S rRNA gene of Cryptosporidium was sequenced. Cryptosporidium was identified from all farms. Types of housing appeared to have no influence with regard to prevalence of infection. Of 971 calves, 345 were infected with Cryptosporidium (35.5%), but more pre-weaned calves (253 of 503; 50.3%) than post-weaned calves (92 of 468; 19.7%) were found to be infected. A total of 278 PCR-positive specimens characterized by gene sequencing revealed Cryptosporidium parvum, Cryptosporidium andersoni, and two unnamed Cryptosporidium genotypes Bovine B (AY120911) and deer-like genotype (AY120910). The prevalence of these Cryptosporidium species and genotypes appeared to be age related between pre- and post-weaned calves. C. parvum, the only zoonotic species/genotype, constituted 85% of the Cryptosporidium infections in pre-weaned calves but only 1% of the Cryptosporidium infections in post-weaned calves. These findings clearly demonstrate that earlier reports on the presence and prevalence of C. parvum in post-weaned cattle that were based solely on oocyst morphology must be reassessed using molecular methods to validate species and genotype. This finding also indicates that persons handling or otherwise exposed to calves under 2 months of age are at greater risk of zoonotic infection from Cryptosporidium than the risk of infection from exposure to older calves.     

猪β_2-肾上腺素能受体初级克隆质粒的改造与鉴定

猪 β2 肾上腺素能受体 (beta2 adrenergicreceptor,β2 AR)基因初级克隆质粒 (pMDAR)在 β2 AR基因 5′端外侧含有 2个EcoRⅠ酶切位点。用EcoRⅠ酶切消化和T4DNA连接酶连接后 ,获得了具有EcoRⅠ单一酶切位点的改造质粒。对经过修饰后的质粒进行了多酶切和 β2 AR基因片段回切等方法鉴定。     

谷氨酰胺与早期断奶仔猪的营养

文章综述了谷氨酰胺对早期断奶仔猪肠道黏膜结构和功能、肠道局部免疫以及生产性能的影响。     

Polymorphism of the DQA2 gene in goats

Variation in the caprine DQA2 gene was investigated using PCR-single-strand conformational polymorphism (SSCP) and DNA sequencing. Eleven DQA2 alleles were defined by SSCP patterns from 23 goats. All the caprine alleles shared high sequence homology to ovine DQA2 sequences, and exhibited a pattern of polymorphism similar to DQA2 alleles from sheep and cattle but different from caprine DQA1 sequences. Thirty-eight AA positions in the alpha1 domain of caprine DQA2 molecules were polymorphic, and a high degree of polymorphism was observed in the putative antigen-binding region, with 74% of the positions being polymorphic. Phylogenetic analysis of caprine, ovine, and bovine DQA sequences revealed that the caprine DQA2 sequences identified here grouped with ovine DQA2, bovine DQA2, DQA3, and DQA4 sequences but are separate from the group of caprine DQA1 alleles. Nine of the caprine DQA2 sequences were more similar to ovine DQA2 alleles, whereas the remaining two were more closely related to ovine DQA2-like and bovine DQA3 alleles. This finding suggests that the caprine DQA2 sequences may represent two loci, which probably arose by either gene duplication or gene conversion events. Allelic lineages were evident for both DQA2 and DQA2-like loci, supporting the trans-species mode of evolution of major histocompatibilitly complex genes. The high level of polymorphism and similarity between caprine and ovine DQA2 alleles suggests that the DQA2 gene may play an important role in immune responses to shared pathogens.