猫泛白细胞减少症弱毒冻干疫苗研制与探索最佳冻干曲线的研究

生物制品进行冷冻干燥过程中，或多或少会损失一定的效价，可直接影响产品效力和免疫原性。本文为研制出高效价和保持期长的猪泛白细胞减少症弱毒冻干疫苗，为降低效价损失，选择出最佳冷冻干燥曲线，使冻干后的产品效价损失减少到最低水平。试验结果选用全程为17h的冻干曲线是科学的、可行的。     

龙头企业与农户利益联结机制的比较研究——根据对四川省畜禽产业链的调查

根据对四川省畜禽龙头企业、合作社及养殖户的实地调研,发现不同的产品特点和产业发展阶段形成不同利益联结机制,这些机制具有不同的约束和激励效果,企业和农户的风险分担和利益分配关系也不同,并决定企业对原料产品质量安全水平的不同控制力。     

猪链球菌2型四川分离株毒力基因的检测及其序列分析

根据猪链球菌2型的MRP、EPF和SLY基因设计合成了四对引物,对我们分离鉴定的2005四川分离株进行毒力因子检测,并对阳性产物测序比较。结果以分离株为模板,获得了与预期结果一致的867bp(MRP)、572bp(EF)的2个片段,以及SLY的长度为1502bp目的片段(外引物)和1443bp的目的片段(内引物)。说明分离株SSsc0501为MRP+EF+SLY+,属于具有3种主要毒力因子的强毒株。经对PCR阳性产物测序及序列分析,结果其与P1/7株的核苷酸序列完全一致,与1933株的同源性达99.7%,仅在128位、217位、744位、1380位、1386位的5个核苷酸发生突变。在氨基酸水平上SSsc0501株与1933株的同源性达99.6%,有2个氨基酸发生替代。     

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。     

关中西部农业产业化的现状与对策

大力推进农业结构不断优化升级,实现产业化经营,是提高中国农业的整体素质、综合效益和国际竞争力的有效途径。在分析关中西部资源、产业现状、制约因素的同时,提出了促进关中西部农业产业化发展的对策和建议。     

恩诺沙星对鸡大肠杆菌病及葡萄球菌病的药效研究

就畜禽专用氟喹诺酮类抗菌药恩诺沙星对鸡人工感染大肠杆菌病及葡萄球菌病的药效进行了研究。结果表明，恩诺沙星、氯霉素对大肠杆菌Ｏ７８的ＭＩＣ分别为０．０５、１．６０ｍｇ／Ｌ；恩诺沙星、红霉素对金黄色葡萄球菌Ｃ５６０５株的ＭＩＣ分别为０．２、３．２ｍｇ／Ｌ。人工发病试验中，恩诺沙星内服以５、１０、２０ｍｇ／ｋｇ剂量或肌注以２．５、５、１０ｍｇ／ｋｇ剂量，每天给药２次，连用３ｄ，对鸡大肠杆菌病及葡萄球菌病均有较好的疗效，其中对大肠杆菌病的疗效明显优于氯霉素     

2020年山东省牛羊疫病报告及监测数据分析

为了解山东省牛羊疫病的流行及免疫现状,汇总2020年山东省牛羊疫病报告数据以及监测数据等信息,分析牛羊疫病的时间分布、空间分布及病种分布;结合监测情况,分析牛羊疫病的免疫状况和暴发风险.2020年山东省牛病以新生犊牛腹泻、牛病毒性腹泻和牛传染性鼻气管炎为主,突发输入性牛结节性皮肤病,羊病以沙门氏菌病、绵羊疥癣和布鲁氏菌...     

Airway hypersensitivity induced by Ascaris suum extract in New Zealand Romney sheep

Sheep from local farms with and without previous exposure to pigs were tested for their skin and airway responses to a commercial Ascaris suum antigen. There was an immediate reaction to intradermal injection of the antigen in 90% of 101 sheep. A bronchial provocation test by aerosol of the same antigen was undertaken on 43 of the sheep with a positive skin reaction. About 70% of sheep showed an immediate airway response to the antigen as an aerosol, reflected as a significant increase in airway resistance and/or decrease of dynamic lung compliance. The mean peak airway resistance and mean lowest dynamic lung compliance were 165% above and 61% below their baselines, respectively. No significant changes were recorded when the same animals were given an aerosol of phosphate buffered saline. Similarly, no correlation was found between the degree of skin reaction and the magnitude of bronchoconstriction (p>0.05). The sheep with previous exposure to pigs showed no significant differences in airway responses to antigen challenge, although they showed significantly greater skin reactions than those without exposure to pigs. These results indicate that the majority of Romney sheep in the Manawatu have a natural skin and airway sensitivity to A. suum antigen and may therefore be used as an animal model to study human airway hypersensitivity. The origin of this sensitivity has yet to be determined.     

从病毒-宿主生态学角度探讨高致病性禽流感防控新策略

1现实的困境和原因自2003年H5N1亚型高致病性禽流感在东亚和东南亚大面积暴发以来,疫情持续蔓延不断,造成无数只家禽感染发病,各受害国共扑杀了数亿只家禽。有些国家(包括我国)还投入巨额资金,进行大规模疫苗接     

Effects of chromium nicotinate on performance, carcase characteristics and blood chemistry of growing turkeys

1. The objective of this trial was to study the effects of chromium nicotinate (Cr) supplementation on the performance, carcase characteristics and blood constituents of 9 to 22 week-old male turkeys. 2. Fifty-four 8-week-old male turkeys weighing 2.9 +/- 0.28 kg were allocated at random into 9 groups with 3 dietary treatments and 3 replicates. The dietary treatment was different dietary concentrations of chromium in the basal diet, to provide 0 (control), 1 or 3 mg/kg. The feeding trial lasted for 14 weeks. 3. Results showed that 1 mg/kg chromium supplementation significantly improved weight gain and food intake at 9 to 18 weeks of age but did not significantly influence performance at 19 to 22 week of age. The breast and thigh muscle were significantly increased in birds receiving 1 mg/kg chromium supplementation but were decreased by 3 mg/kg of supplementation. 4. Dietary chromium supplementation did not significantly influence other serum constituents, including insulin, HDL, VLDL+LDL, HDL-C, VLDL-C+LDL-C, total protein, albumin, and gamma-globulin at 18 and 22 weeks of age. 5. The serum triacylglycerol (TG) and uric acid contents were significantly increased, while glycerol and alpha-globulin were significantly reduced by 3 mg/kg chromium supplementation. However, 1 mg/kg chromium supplementation significantly reduced serum cholesterol and glycerol at 18-weeks old. At 22 weeks of age, 1 mg/kg chromium supplementation significantly increased serum glucose and decreased the uric acid concentration whereas 3 mg/kg chromium supplementation significantly increased the creatinine concentration and decreased beta-globulin concentration.