模猪场猪瘟野毒感染情况调查

利用ELISA方法对广西6个规模猪场送检的1626份猪血清进行猪瘟野毒感染情况调查。结果6个规模猪场均存在猪瘟野毒感染,其中母猪感染率为7.86%~29.21%,平均为17.52%,种公猪感染率为0%~23.52%,平均为11.83%,育肥猪感染率为5%~22.45%,平均为15.5%,断奶仔猪感染率为8.24%~18.57%,平均为12.69%。此检测结果与猪场临床发病情况基本一致,病猪多表现为繁殖障碍型、温和型的非典型猪瘟。     

Efficacy, duration, and onset of immunogenicity of a West Nile virus vaccine, live Flavivirus chimera, in horses with a clinical disease challenge model

REASON FOR PERFORMING STUDY: West Nile virus (WNF) is a Flavivirus responsible for a life-threatening neurological disease in man and horses. Development of improved vaccines against Flavivirus infections is therefore important. OBJECTIVES: To establish that a single immunogenicity dose of live Flavivirus chimera (WN-FV) vaccine protects horses from the disease and it induces a protective immune response, and to determine the duration of the protective immunity. METHODS: Clinical signs were compared between vaccinated (VACC) and control (CTRL) horses after an intrathecal WNV challenge given at 10 or 28 days, or 12 months post vaccination. RESULTS: Challenge of horses in the immunogenicity study at Day 28 post vaccination resulted in severe clinical signs of WNV infection in 10/10 control (CTRL) compared to 1/20 vaccinated (VACC) horses (P<0.01). None of the VACC horses developed viraemia and minimal histopathology was noted. Duration of immunity (DPI) was established at 12 months post vaccination. Eight of 10 CTRL exhibited severe clinical signs of infection compared to 1 of 9 VACC horses (P<0.05). There was a significant reduction in the occurrence of viraemia and histopathology lesion in VACC horses relative to CTRL horses. Horses challenged at Day 10 post vaccination experienced moderate or severe clinical signs of WNV infection in 3/3 CTRL compared to 5/6 VACC horses (P<0.05). CONCLUSIONS: This novel WN-FV chimera vaccine generates a protective immune response to WNV infection in horses that is demonstrated 10 days after a single vaccination and lasts for up to one year. POTENTIAL RELEVANCE: This is the first USDA licensed equine WNV vaccine to utilise a severe challenge model that produces the same WNV disease observed under field conditions to obtain a label claim for prevention of viraemia and aid in the prevention of WNV disease and encephalitis with a duration of immunity of 12 months.     

Reducing methane emissions and the methanogen population in the rumen of Tibetan sheep by dietary supplementation with coconut oil

The objective was to evaluate the effect of dietary coconut oil on methane (CH(4)) emissions and the microbial community in Tibetan sheep. Twelve animals were assigned to receive either a control diet (oaten hay) or a mixture diet containing concentrate (maize meal), in which coconut oil was supplemented at 12?g/day or not for a period of 4?weeks. CH(4) emissions were measured by using the 'tunnel' technique, and microbial communities were examined using quantitative real-time PCR. Daily CH(4) production for the control and forage-to-concentrate ratio of 6:4 was 17.8 and 15.3?g, respectively. Coconut oil was particularly effective at reducing CH(4) emissions from Tibetan sheep. The inclusion of coconut oil for the control decreased CH(4) production (in grams per day) by 61.2%. In addition, there was a positive correlation between the number of methanogens and the daily CH(4) production (R?=?0.95, P?相似文献   

宁夏首起牛结节性皮肤病疫情流行病学调查

2020年10月,宁夏盐池县、利通区、平罗县发生输入性牛结节性皮肤病疫情。为查明疫情发生原因,分析疫情扩散风险,宁夏回族自治区农业农村厅畜牧兽医局组织成立督导组进行流行病学调查。通过现场调查、座谈及实验室检测,综合发病、溯源和追踪情况以及实验室检测结果,分析认为此次疫情是由调入纯种荷斯坦育成奶牛引起的。因及时采取了封锁疫点、控制移动、扑杀、无害化处理、清洗消毒、杀灭蚊蝇、免疫等综合处置措施,疫情扩散风险较低。此次疫情警示,要强化牛只及其产品的调运监管,加强疫情排查监测,及时发现和处置疫情。     

卡死克对草地天敌昆虫通缘步甲的影响

试验研究了卡死克对通缘步甲成虫的急性致死毒性及田间撒施卡死克毒饵后对其种群数量消长的影响。室内口腔灌喂250ppm浓度的卡死克药液2μl／头后的第1～15天，灌药组与灌清水组的存活率均在70～90％，统计结果无显著差异，说明药剂对该步甲元急性致死毒性。在毒饵撒施后的7～17天，采用陷阱诱捕法调查对通缘步甲田间种群数量的影响，结果表明：处理区与对照区的日均诱捕数量为28．3和28．5头，两区间的差异并不显著。卡死克既不杀伤草地上游猎捕食的通缘步甲又能有效控制蝗虫种群数量的增长，使其能够发挥控制害虫的作用。通缘步甲发生数量大，与蝗虫种群消长有跟随现象，是一种值得研究保护利用的优势天敌种类。     

AA肉鸡腿肌重活体估测方法的探讨

以AA肉鸡商品代为试验材料,分析0、7、14、21、28、35、42日龄公、母鸡整体和腿肌的累积生长,建立腿肌重(y)与活重(x)之间的直线回归、幂回归、指数回归、对数回归及多项式回归方程,探讨腿肌重的活体估测方法。结果表明,AA肉鸡的腿肌在后期生长迅速,尤其是公鸡在35～42日龄时期表现突出;腿肌重(y)与活重(x)的幂回归、直线回归、多项式回归方程的拟合精度均在0.95左右,效果较好。     

限饲对肉鸡的影响

从上世纪20年代肉用仔鸡兴起至今已经过了80多年，这期间科研工作者和生产者无论从肉鸡的选育角度和饲养角度，都是单纯追求提高肉鸡的增重速度，这样虽然使肉用仔鸡的出场日龄大大提前，但肉鸡生长过快，也使肉鸡的体重迅速增长与骨骼、内脏器官发育缓慢之间的矛盾更加突出。肉鸡出现猝死症、腿部畸形和腹水症等疾病，     

野兔圈养管理技术

野兔肉质细嫩、香醇、味美,并含有丰富的人体所需的营养物质,特别是胆固醇含量很低(仅为0.4%),是消费者特别是心血管患者及肥胖者理想的动物蛋白食品。野兔家养成为近几年来发展起来的新兴产业,由于需要较高的管理技术,在很多地方还处于试养阶段,还没有形成规模,野兔的供应还远远不能满足市场的需要,发展前景看好。我所于2006年引进种兔5组,采取圈养的方式进行饲养并获得成功。为了使这一产业在我州得以推广,现将野兔家养的关键技术总结如下。1圈舍的准备根据不同的条件,可修建砖混结构的圈舍,也可利用废弃的猪圈、牛圈、羊圈和鸡鸭舍稍加改…