哺乳动物卵母细胞孤雌激活的研究进展

本文对哺乳动物卵母细胞孤雌激活机制、激活方法及激活效果的影响因素等作了浅要的综述和总结。     

Hepatogenous photosensitization associated with liver copper accumulation in buffalos

Four 1.5-year-old, male, Murrah buffalos were maintained during eight months without direct solar exposure during a study of copper toxicosis. Four days after solar exposure, all buffalos presented clinical manifestations consistent with acute photosensitization, including anorexia, apathy, loss of body weight, and generalized cutaneous lesions. Gross lesions were characterized by severe erythema, localized edema, fissures, tissue necrosis, gangrene and crust formation with serous exudation. Liver copper concentration was evaluated, and cutaneous biopsies were taken when clinical signs were evident. The liver copper concentration before solar exposure was increased in all animals. Histopathologic examination of the skin revealed hepatogenous photosensitization characterized by parakeratotic hyperkeratosis, acantholysis, degeneration of squamous epithelial cells, epidermal necrosis with atrophy of sweat glands, and multifocal superficial and deep dermal edema. These findings suggest that asymptomatic accumulation of copper within the liver might have induced hepatic insufficiency thereby resulting in secondary photosensitization when these buffalos were exposed to sunlight.     

珍稀植物北碚榕的种子萌发及繁殖研究

以北碚榕种子为材料,研究酸蚀与浸种时间、萌发基质与温度、光照条件和赤霉素处理对种子萌发的影响,通过育苗将幼苗移栽到田间.结果表明,北碚榕种子经酸蚀处理后可以萌发.适宜的酸蚀时间为3~5min,浸种时间为4~8h(30℃),萌发基质为河沙,萌发温度为(25±1)℃(3 000lx每天光照12h).在此条件下,15d发芽率可达90%以上.每天光照24h和300~400mg/L赤霉素(GA3)浸种能显著提高发芽率.幼苗在培养皿蛭石中成苗率达85%以上,在穴盆营养土中和营养钵沙壤土中成活率均达95%以上,田间移栽成活率达100%,生长正常.解决了北碚榕的种子萌发问题,初步获得了育苗技术,为北碚榕的种子繁殖奠定了基础.     

鸡新城疫Ⅰ系疫苗株Vero细胞培养物的免疫试验及Vero细胞的致瘤性检查

对鸡新城疫Ⅰ系毒 Ｖｅｒｏ 细胞培养物进行了安全性及免疫试验。结果表明, Ⅰ系毒 Ｖｅｒｏ 细胞培养物对２月龄鸡是安全的。免疫试验结果表明, Ⅰ系毒 Ｖｅｒｏ 细胞培养物与鸡胚毒一样, 具有良好的免疫原性, 免疫２ 月龄鸡４ 个月后, Ｈ Ｉ抗体还在６ｌｏｇ２ 以上, 免疫成年鸡１３ 个月后, Ｈ Ｉ抗体还高达５５ｌｏｇ２ 。试验还证明, Ｖｅｒｏ 细胞对鸡没有致瘤性, 安全可靠, 可以用于鸡新城疫疫苗的生产。     

日本“家族经营协议的内容与模式分析

“家族经营协方”在日本农业经济中已经越来越被重视和推广。“家族经营协议”是指在日本农业经济中,为培育法人经营,确保务农事业后继有人,确立 家族务农场的法律地位而形成的一种民法。它的中心目标是把农业作为一种职业,认人们自由选择。同时,“家族经营协议”：以形式确定劳动力在生产经营中的重要作用,也给日本经济带来了新生命力,根据得中国学习借鉴。     

肉种鸡能量限饲对胚胎期血清脂类代谢相关指标影响

文章对产蛋期AA肉种鸡进行能量限饲,旨在探讨其对胚胎期血清脂类代谢相关指标影响。选用20周龄肉种母鸡400羽,随机分为4组,每组5个重复,每个重复20羽。当产蛋率达到5%时开始正式试验,对照组饲喂基础日粮,试验组日粮能量水平分别为基础日粮能量80%、70%、50%,对照组和试验组均限饲且饲喂量相同,于产蛋期(37~39周龄)进行人工授精并按肉种鸡分组收集种蛋(每组150枚)后孵化,分别于13、15、17、19和21胚龄采集血清样品。结果表明,①肉种鸡能量限饲显著提高了15胚龄各试验组及17、19、21胚龄80%能量组血清CHO含量(P<0.05)、13胚龄80%能量组TG含量(P<0.05)。②肉种鸡能量限饲显著降低了13、15、19胚龄各试验组血清GLU含量(P<0.05)和17胚龄各试验组血清LDL含量(P<0.05)。③肉种鸡能量限饲显著提高了15胚龄70%和80%能量组及17胚龄80%能量组血清T3含量(P<0.05)、15胚龄80%能量组及21胚龄70%和80%能量组血清T4含量(P<0.05),显著降低了17胚龄50%能量组血清T3含量(P<0.05)及13胚龄70%能量组血清T4含量(P<0.05)。④肉种鸡能量限饲显著降低了13胚龄70%、80%能量组及21胚龄80%能量组血清LEP含量(P<0.05),13胚龄80%能量组血清INS含量(P<0.05),17、19、21胚龄试验组血清GH含量(P<0.05)。以上结果显示,肉种鸡能量限饲对胚胎期血脂代谢指标影响存在着母体效应,表现为对血清CHO、TG含量提升作用和对血清GLU、LDL、LEP、INS、GH含量降低作用。     

The first report on Cryptosporidium suis and Cryptosporidium pig genotype II in Eurasian wild boars (Sus scrofa) (Czech Republic)

A total of 193 faecal samples of adult Eurasian wild boars were collected at 12 enclosures across the Czech Republic and examined for Cryptosporidium infection using both microscopic and molecular tools. Cryptosporidium oocysts were not detected in any of the 193 faecal samples examined using the aniline-carbol-methyl violet staining method. Thirty-two positive cases of Cryptosporidium infection were detected using either genus- or species-specific nested PCR. Mono-infection with Cryptosporidium suis and Cryptosporidium pig genotype II were found in 13 and 7 cases, respectively. Five mixed infections of C. suis and Cryptosporidium pig genotype II were detected using PCR/RFLP with genus specific primers. The number of detected mixed infections increased 2.4 fold when a species-specific PCR was employed. No other Cryptosporidium spp. was detected. Unlike cryptosporidiosis of domestic pigs, C. suis was detected as a dominant species infecting adult Eurasian wild boars. There was no association between diarrhoea and the presence of Cryptosporidium infection in the Eurasian wild boars studied. This is the first report on the Cryptosporidium infection caused by C. suis and Cryptosporidium pig genotype II in Eurasian wild boars (Sus scrofa).