Cryptosporidiosis in buffalo calves (<Emphasis Type="Italic">Bubalus bubalis</Emphasis>): Prevalence and potential risk factors

The objective of the present study was to describe the prevalence and risk factors associated with cryptosporidiosis in buffalo calves in Middle Egypt. During one year, 458 fecal samples were collected from buffalo calves less than 3 month age in 55 small scale herds and examined for the presence of Cryptosporidium oocysts. Data describing age, gender, season, and herd management practices were gathered to assess potential risk factors. Fecal examination showed that 14.19% of the examined calves were positive for Cryptosporidium spp. Calves at 1-15 days were at the highest risk (P < 0.001), and a significant relationship between season and infection (P < 0.05) was recorded. A significant association between infection and hygiene (P < 0.001), type of floor (P < 0.01) and source of water (P < 0.01) was also recorded. Statistical analysis concerning the clinical signs and fecal characteristics revealed a significant association with fecal consistency (P < 0.001), presence of blood (P < 0.01) and mucous (P < 0.01). Moreover, a significant association was found between infection and the desire for suckling (P < 0.05) and tenesmus (P < 0.05). The results of the present study demonstrated the strong relation between infections by Cryptosporidium spp. and diarrhea in buffalo calves.     

ELISE测定猪尿、猪肝中克伦特罗残留的研究

ELISA(酶联免疫吸附法)测定猪尿、猪肝中违禁药物克伦特罗残留量影响实验结果表明,德国拜发与北京望尔生产的两种ELISA试剂盒具有操作简单、时间短、成本低、敏感度高等特点。在室温20-22℃条件下,试验制备过程中必须做到控温度、控转速、控流速及洗板过程中应注意事项,这样可大大提高在实际操作过程中检测的准确性。     

猪繁殖与呼吸综合征病毒致病机理的研究进展

猪繁殖与呼吸综合征(PRRS)是由猪繁殖与呼吸综合征病毒(PRRSV)引起的一种以妊娠母猪严重繁殖障碍及仔猪的呼吸道症状和高死亡率为特征的传染病。现已遍及世界各主要养猪国家和地区,成为危害养猪业最严重的传染病之一。作者就猪繁殖与呼吸综合征病毒致病机理方面的研究情况作一综述,为诊断技术、免疫机理研究、疫苗设计和疫病防制提供借鉴。     

Farmers’ perceptions of the causes of low reproductive performance in cows kept under low-input communal production systems in South Africa

The objective of the study was to determine farmers’ perceptions of the causes of low reproductive performance in Nguni cows raised on communal rangelands in the Eastern Cape Province of South Africa. Data were collected using participatory rural appraisals and structured questionnaires that were administered to 551 randomly selected farmers from ten communities in the Eastern Cape. Cattle herd sizes ranged from 3 to 11 and were mainly composed of cows. Cattle sales were ranked as the most important use of cattle in all the villages. Tick-borne diseases and poor animal condition were reported as chief constraints of cattle production in most communities. More than 60% of the interviewees reported that the age at puberty and age at first calving for their cows varied between 18 and 36, and 24 and 48 months, respectively. About 95% of the respondents reported long calving intervals and low bull numbers as major causes of low reproductive performance in cows in the communal areas. It was concluded that farmers perceived delayed age at puberty and at first calving, long calving intervals and low bull numbers as the major causes of low reproductive performance in Nguni cows raised on communal rangelands in South Africa.     

Ovicidal activity of seven <Emphasis Type="Italic">Pochonia chlamydosporia</Emphasis> fungal isolates on <Emphasis Type="Italic">Ascaris suum</Emphasis> eggs

The ovicidal effect of the nematophagous fungus Pochonia chlamydosporia on eggs of Ascaris suum was tested under laboratory conditions. A. suum eggs were plated on 2% water–agar with seven fungal isolates (Isol. 5, Isol. 31, Isol. 1, VC1, Isol. 12, Isol. 22 and VC4) and control without fungus. After 5, 7, 10, 14, 15 and 21 days of incubation, approximately 100 eggs were removed from the plates and classified according to the following parameters: type 1, biochemical and physiological effect without morphological damage to the eggshell, type 2, lytic effect with morphological alteration of the eggshell and embryo and type 3, lytic effect with morphological alteration of eggshell and embryo showing hyphal penetration and internal egg colonization. The isolates effectively destroyed A. suum eggs and all types of effects were observed during the experiment. There was no variation in ovicidal capacity (type 3 effect) among the isolates (p > 0.05) throughout the experiment. After 21 days, isolate 5 showed the highest percentages of type 3 effect (58.33%). The results indicated that P. chlamydosporia (Isol. 5, Isol. 31, Isol. 1, VC1, Isol. 12, Isol. 22 and VC4) can destroy A. suum eggs and is, therefore, a potential biological control agent of nematodes.     

Circulating oxidative stress status in dromedary camels infested with sarcoptic mange

Oxidative stress is an imbalance between radical-generating and radical-scavenging activity, resulting in oxidation products and tissue damage. This study was aimed to evaluate the status of oxidative stress indices in blood of camels naturally infested with S. scabiei. Forty-seven male camels (Camelus dromedaries) were divided according to the extent of the infested area with Sarcoptes scabiei into four groups, mild (MID, n = 12), moderate (MOD, n = 10), severely infested (SEV, n = 10) and healthy control group (n = 15). Blood was used for determination of red cell count (RBC), hemoglobin (Hb), packed cell volume (PCV), serum nitric oxide (NO^•, a free radical), ascorbate and albumin concentrations, and erythrocytic values of malondialdehyde (MDA, a marker of lipid peroxidation), protein carbonyls (PC, an indicator of protein oxidation), glutathione (GSH) superoxide dismutase (SOD) and catalase (CAT). Decreased levels (P < 0.05) of RBC, Hb, PCV, albumin and ascorbate were noticed in MOD and SEV compared to controls with the lowest values (P < 0.05) in SEV except for ascorbate, where MOD did not differ from SEV. Compared to controls, NO^• gradually increased (P < 0.05) in MID followed by MOD and SEV, whereas MDA and PC were higher (P < 0.05) in MOD and SEV. PC was higher (P < 0.05) in MOD than SEV. In addition, the antioxidants GSH, SOD and CAT were higher (P < 0.05) in MID and lower (P < 0.05) in MOD and SEV compared to controls. GSH was lower (P < 0.05) in SEV compared to MOD. Besides, Hb was negatively correlated with NO^• (r = −0.68, P < 0.001), MDA (r = −0.53, P < 0.001) and PC (r = −0.73, P < 0.001). In conclusion, dromedary sarcoptosis is accompanied by a state of oxidative stress process, which increased by increasing the area of infestation, and may contribute to the pathogenesis of the disease.     

新城疫病毒实时荧光RT-PCR检测方法的建立与应用

为满足新城疫病毒高通量快速检测的需要,针对新城疫病毒M基因序列,通过基因比对分析保守区域,经同源性分析后,设计合成多条引物和探针并对其筛选,建立了一种能够快速检测新城疫病毒的实时荧光RTPCR检测方法,并对该方法的特异性、灵敏性进行了评估。结果显示,该方法检测耗时短、特异性好,检测下限达10~(-4) ng/μL。利用该方法,对480份临床采集的各类家禽咽拭子样品进行检测,共检测出25份阳性,与常规RT-PCR检测方法结果一致,κ值为1(P 0.001)。结果表明,该方法快速、准确,可用于新城疫病毒的快速检测。     

我国居民肉类消费情况调查

为更好研究落实2020年中央1号文件作出的决策部署,对居民肉类消费情况进行了调查。本次调查对全国30个省(区、市)各年龄层次、收入水平的1 060名居民,进行了猪肉、牛肉、羊肉、禽肉、水产品等肉类消费情况和习惯摸底。结果显示:2019年我国居民日常猪肉消费量有所降低,但猪肉仍是主要肉类消费产品;居民喜食热鲜猪肉的消费习惯已发生变化,对冷鲜猪肉接受度较高,对冷冻猪肉接受度低;卫生安全和价格是影响居民对猪肉消费决策的主要因素。可考虑从创新检疫工作模式,重点扶持"养殖-屠宰-销售"一体化企业,强化冷冻肉技术研发和推广,利用新媒体进行舆论引导等4个方面,进一步提高居民对冷鲜、冷冻肉品的认可度,为未来推动从"调猪"向"调肉"转变提供良好的市场环境。     

Ghrelin对雌激素诱导雄性小鼠胸腺萎缩的逆转及对相关细胞因子基因表达的影响

SPF级6周龄Balb/c雄性小鼠60只,随机分为3组,每组20只,适应饲养1周后进行动物试验.雌激素+Gh-relin试验组:前2周隔日腹腔注射苯甲酸雌二醇注射液(含苯甲酸雌二醇0.1 mg)0.05 mL/只,后2周按每日腹腔注射Ghrelin(含Ghrelin 60 μg)0.1mL/只;雌激素+生理盐水对照组:前2周隔日腹腔注射苯甲酸雌二醇注射液(含苯甲酸雌二醇0.1mg)0.05mL/只,后2周按每日腹腔注射0.9％生理盐水0.1 mL/只;生理盐水对照组:前2周按0.05 mL/只隔日腹腔注射0.9％生理盐水,后2周按0.1 mL/只每日腹腔注射0.9％生理盐水.动物试验结束后,统计小鼠胸腺指数,应用光镜观察胸腺形态学变化,采用实时荧光定量PCR法检测胸腺中12种细胞因子mRNA表达量的变化.结果显示,注射Ghrelin后,雌二醇诱导的小鼠胸腺萎缩在形态学上基本恢复到正常水平,胸腺中白细胞介素1(IL-1)、IL-2、IL-4、IL-6、IL-12、干扰素(1FN-γ)、白血病抑制因子(LIF)、抑瘤素(OSM)、干细胞因子(SCF)、胸腺体液因子(THF)、肿瘤坏死因子(TNF-α) mRNA含量显著降低(P＜0.05),而IL-7 mRNA含量稍微升高(P＞0.05).结果表明,Ghrelin对雌激素诱导的小鼠胸腺萎缩具有逆转作用,其机制可能是:一方面通过抑制IL一6、OSM、LIF、SCF等细胞因子的表达,从而促进胸腺细胞的增殖;另一方面通过抑制IL-1、IL-2、IL-4、IL-12、THF等细胞因子的表达,从而减少TNF-α和IFN-γ的分泌,进而抑制胸腺细胞的凋亡.