文昌鸡产蛋性能及蛋品质研究

本文就文昌鸡产蛋规律、种蛋品质进行研究.结果表明:文昌鸡开产后第7周前产蛋率快速上升,到开产后第7周或第8周,产蛋率到达最高峰,60%以上的产蛋率能维持15～18周,经过产蛋高峰期后,产蛋率缓慢下降,期间略有波动,说明文昌鸡的产蛋性能良好;文昌鸡55周龄蛋品质性状蛋重(EW)、蛋壳重(SW)、蛋壳厚度(ST)、蛋壳强度(SS)、哈氏单位(HU)、蛋形指数(SI)、蛋黄重(YW)、蛋黄颜色(YC)的测定结果平均值分别为49.00g、6.34 g、320.69μm、4.01 kg/cm2.70.02、1.31、16.45 g、6.13.     

Identification and characterization of IgA1 protease from Streptococcus suis

Streptococcus suis (S. suis) is a major swine pathogen and an emerging zoonotic agent. However, the current understanding of the S. suis pathogenesis of infection remains limited. In the present study, an IgA1 protease of S. suis was identified for the first time. The protein was recombinantly expressed in Escherichia coli, and the purified recombinant protein showed good cleaving reactivity to IgA1 and was highly immunoreactive to convalescent sera. The gene was found to exist in most pathogenic strains but scarcely in non-invasive isolates. These findings suggested that the IgA1 protease might play an important role in the pathogenesis of S. suis.     

疑似犬传染性支气管炎暴发的病例报告

<正>近日,某基地及周边60余头工作犬暴发了以强烈阵咳、呕吐白色粘液、发热、传播迅速为主要特征的急性呼吸道疾病。时值甲型H1N1流感高发季节,我们及时采取综合治疗措施,在较短的时间得到有效控制,并     

谷氨酰胺二肽在断奶仔猪饲料中应用的可行性

<正>谷氨酰胺(Gln)是唯一具有抗氧化和渗透特性的氨基酸,是动物肠、肝和免疫细胞优先利用的燃料,是抗氧化物的前体,并被认为是在炎症情况下的一个条件性必需氨基酸。在应激状态下,Gln通过动物肠道或非肠道减少细菌在细胞内的粘附来减少细菌移位的发生。Gln为蛋白合成提供氮的先体,是快速分裂细胞优先利用的呼吸燃料。已有大量研究证实,Gln能减轻断奶仔猪的腹泻,提高其生产性能。     

四川省宜宾市屠宰企业非洲猪瘟病毒核酸检测能力比对

屠宰企业的非洲猪瘟自检对切断病毒传播链条、打好非洲猪瘟攻坚战有着重要作用。为摸清四川省宜宾市屠宰企业的非洲猪瘟检测水平,对全市10个区县83家屠宰企业组织开展了非洲猪瘟检测能力比对工作。结果显示:屠宰企业检测人员偏少、岗位工作时间短、文化程度不高;不同区县、不同类别、不同组合的检测结果存在差异,有的差异较大。总的检测敏感性为49.72%,特异性为87.41%,准确率为66.56%。结果表明:屠宰企业的检测能力较为一般,监测风险预警效果不甚理想,有待加强。建议从保障人员队伍和加强操作培训两方面入手,提高屠宰企业非洲猪瘟检测能力。     

一起牛结节性皮肤病案例的处置评析

动物疫病应急处置是有效防控重大动物疫病,保障动物及动物产品安全,保护养殖业安全和公共卫生安全的重要手段。本文梳理了农业农村部通报的福建长汀县一起牛结节性皮肤病案例的案情概况与处置要点,通过分析案例,提示应及时确诊病例,规范处置传染病,做好紧急免疫,加强监管和联防联控,正面引导舆情,积极开展科普宣传。本案例处置为加强牛结节性皮肤病防控,保障养牛业持续健康发展和官方兽医依法行政提供了参考。     

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     

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.     

硒增强雏鸡对IBD抵抗力机制的细胞免疫研究

为了解硒对雏鸡传染性法氏囊病（ＩＢＤ）抵抗大的影响及其细胞免疫机制，自１日龄起给雏鸡分别饲喂基础（含硒０．０８６ｍｇ／ｋｇ）、补硒０．３ｍｇ／ｋｇ和０．６ｍｇ／ｋｇ的不同日粮，于４９日龄采用微量全血培养￣３Ｈ－ＴｄＲ掺入法测定其中自然发生ＩＢＤ后第１０天和正常对照雏鸡的Ｔ淋巴细胞转化率，并计算ＩＢＤ鸡死亡率。结果，两补硒组ＩＢＤ雏鸡死亡率显著低于基础日粮组ＩＢＤ雏鸡（Ｐ＜０．０１）；ＩＢＤ明显抑制雏鸡Ｔ淋巴细胞转化率（Ｐ＜０．０５；Ｐ＜０．０１）；补硒的正常对照雏鸡和ＩＢＤ雏鸡Ｔ淋巴细胞转化率分别高于各自基础日粮雏鸡（Ｐ＜０．０５；Ｐ＜０．０１）。结果显示补硒可提高雏鸡细胞免疫功能，从而增强雏鸡对ＩＢＤ抵抗力，降低雏鸡死亡率。     

短周期间歇光照对肉用仔鸡生产性能的影响

在７日龄时,肉服仔鸡由接近全日制光照改变为１ｈ光照,３ｈ黑暗的短周期简歇光照。结果表明,短周期间歇光照的肉仔鸡饲料报酬和饲料利用率提高,氮平衡试验表明,增加肉用仔鸡的光周期,粪氮分泌量减少,饲料氮在鸡体内的沉积增加,而饲料氮的摄入量并未增加,因而使得饲料氮的利用率和到提高。