INTERACTION BETWEEN INFECTIOUS BURSAL DISEASE VIRUS AND NEWCASTLE DISEASE VIRUS IN CHICKENS

The Australian strain of infectious bursal disease virus (IBDV), 002/73, affected the response of chickens to Newcastle disease virus (NDV). The titre of serum antibodies to NDV in chickens infected with IBDV was significantly lower than that of birds infected with NDV alone. It also appeared that IBDV affected NDV excretion from chickens as NDV was more frequently isolated from chickens infected with IBDV, IBDV infection did not alter the pathogenicity of NDV in chickens. This Australian strain of IBDV therefore appeared to be immunodepressive in one-day-old chickens.     

雏鸡绿脓杆菌病的病理形态学研究

不同菌量的绿脓杆菌，通过皮下，腹腔和嗉接种１５０只一日龄雏鸡，取各种组织做石蜡切片和超薄切片，进行光镜和电镜观察。结果，一日龄雏鸡三种途径接种都出现脑组织出血和水肿，肺间质水肿和脾坏死。电镜观察，病变组织的血管周围有大量绿脓杆菌，血管壁纤维变性和崩解，提示绿脓杆菌对血管壁的损伤在本病的发生中起重要作用。     

马黄曲霉毒素中毒性流产的诊断研究

陕西眉县土岭马场突发性马流产,主要病理变化为皮下,粘膜及内脏出血,肝脏和肾脏变性坏死。真菌检验:该场各种饲草、饲料及畜体内外环境中黄曲霉出现率为100％,污染率为8.3～100％。黄曲霉毒素B_1测定:1.流产马驹胃肠内容物、马厩暴皿培养及混合饲料中,产生黄曲霉毒素B_1菌株检出率为96.3％;2.混合饲料中黄曲霉毒素B_1含量为250ppb;3.流产马驹肝脏中黄曲霉毒素B_1残留量达60ppb。生物活性测定证实,自饲料与畜体分离的黄曲霉均具有较强烈的病原性与致死性。     

鸡马立克氏病双价疫苗的免疫效力试验

用“814”、B-1/att弱毒疫苗和HVT疫苗匹配组成双价疫苗,进行实验室和田间免疫效力试验。实验室试验表明,由“814”和HVT匹配构成的双价疫苗,免疫效果很好,优于单价疫苗,尤其明显优于HVT单价疫苗。此双价疫苗的田间试验,也取得了令人满意的结果。     

雏鸡在感染IBDV后红细胞免疫功能变化的研究

在经ＩＢＤ弱毒苗免疫和未免疫的３０～５９日龄ＡＡ鸡研究了感染ＩＢＤＶ后红细胞免疫功能的变化。结果表明：从以ＩＢＤＶ攻毒前１天到攻毒后头５天内,未免疫攻毒鸡（Ａ组）和免疫攻毒鸡（Ｂ组）ＲＢＣ－ＣＲ１花环率降低或显著降低,而未免疫未攻毒鸡（Ｃ组）没有类似变化,高于Ｂ组,明显高于Ａ组,以后Ａ和Ｂ组逐渐回升到攻毒前水平。Ａ和Ｂ组ＲＢＣ－ＩＣ花环率在ＩＢＤＶ攻毒后第５天明显降低,均显著低于Ｃ组水平,以后Ａ组仍处于较低水平上变动,Ｂ组即逐渐回升,三组比较,Ａ组仍低于Ｃ组,同时也低于Ｂ组。     

TUBERCULOSIS-LIKE GRANULOMAS IN CATTLE CAUSED BY ACTINOMYCETES

From 280 lesions from normal cattle at slaughter, 10 were found to contain thin, branching, Gram-positive organisms belonging to the Nocardia/Streptomyces group and this was confirmed by culture in 3 cases. Macroscopically the older lesions were similar in appearance to those of tuberculosis. Microscopically, all lesions contained numerous foreign body giant cells and thin, branching organisms. The older lesions also contained areas of necrosis, caseation, mineralisation and fibrosis.