Within-flock transmission of sheep scab in naive sheep housed with single infested sheep.

The within flock transmission of sheep scab was studied in two trials, which lasted 14 and 12 weeks, respectively. A total of 40 non-infested, scab-naive sheep were divided into six groups of between 6 and 20 individuals. Each group was subsequently housed with a single infested index case, carrying scab lesions of different ages. The groups of sheep in both trials were video recorded continuously and all the sheep were individually examined on a weekly basis. The occurrence of transmission was measured in two ways: first, by the detection of early scab lesions during clinical examination and, second, by an increase in the rubbing of individual sheep as noted from the analysis of the video recordings. These two methods complemented each other in predicting the week on which transmission occurred. Overall, transmission was detected in 34 of the 40 scab-naive sheep. Transmission was shown to occur at about the time when the population of adult mites in lesions on index cases reached their peak numbers. The highest number of mites at this time, however, differed markedly between index sheep. There was no obvious relationship between the incidence of transmission and the time index sheep spent rubbing each day or other index sheep variables, including the age of the lesion or the time since the introduction to the scab free sheep.     

夏洛莱与小尾寒羊杂交育肥试验

夏洛莱绵羊是世界著名的肉羊品种，该品种具有早熟、耐粗饲、采食能力强、适应性强等特点。体型外貌特征：体躯长、胸深宽、背腰平直、后躯宽大呈倒“U”字形、四肢较短。在我国河北、河南、山东等地通过杂交组合生产出的肥羔结构良好。引进夏洛莱绵羊与当地小尾寒羊杂交，其目的在于利用夏洛莱的优良特性，进行经济杂交．并筛选出生长发育快、早熟、体大、产肉性     

陶赛特羊杂交改良本地羊的效果观察

对50只陶本F1羊的生长发育指标进行了测定,同时与同龄的本地羊进行比较。结果发现,陶本F1羊4月龄和6月龄体重分别比同龄本地羊增加3.39 kg、4.45 kg(P0.01)。4月龄陶本F1羊的体高、胸围和体斜长分别比同龄本地羊提高5.72 cm、5.95 cm和7.63 cm。6月龄陶本F1羊分别比同龄羊提高5.87 cm、7.28 cm和7.80 cm(P0.01)。     

策勒黑羊、和田羊和卡拉库尔羊血液蛋白多态性研究

血液蛋白多态性可以作为一个遗传标记因子来反映动物的遗传变异情况。不同品种间的不同位点血液蛋白具有一定差异,所以由多种血液蛋白多态性所标记的多基因型,可用来标记品种特征（张细权,1997）。本研究利用血液蛋白多态性,对塔里木盆地周边的策勒黑羊、和田羊、卡拉库尔羊3个绵羊品种进行遗传多样性分析,对种质资源保护和科学开发利用以及品种的起源、进化研究提供科学依据。     

Control of sheep scab and other sheep ectoparasites with propetamphos

Propetamphos is a new organophosphorous compound with broad spectrum acaricidal and insecticidal activity. Dip wash concentrations of 100 to 200 ppm protect sheep against field challenge for approximately 10 weeks for blowflies, 16 weeks for lice and keds and six weeks for ticks. During laboratory and field trial studies a wash concentration of 125 ppm propetamphos eradicated sheep scab and protected from reinfestation for over four weeks.     

工厂化高效养羊(Ⅰ)

1工厂化高效羊业是我国羊业的根本出路 1.1我国的国情与发展高效养羊业的必要性 我国基本国情是:人口众多、可耕土地少、粮食短缺、资金不足.依据国情选择有利于节约粮食资源和保护环境的产业结构和消费方式,将成为我国的一项基本国策.