共查询到20条相似文献,搜索用时 140 毫秒
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D-loop环作为线粒体DNA重要的一个区域,已被广泛用于物种起源分化、系统进化等方面的研究。本文简要介绍了线粒体DNA D-loop环的结构特征及其研究方法,并综述了近年来猪线粒体DNA D-loop环的研究进展。 相似文献
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Breeding success (fledglings pair?1 y?1) of the Red-listed African Black Oystercatcher (Haematopus moquini) is highly variable, both spatially and temporally. Despite a diversity of natural factors causing this variability, there is evidence that two anthropogenic factors, i.e. disturbance and an introduced mussel (Mytilus galloprovincialis), are having an impact on the local breeding success of this species. Using a data set comprising 87 site-years of nest-monitoring data across most of the species’ breeding range, we analysed the extent and causes of variability in breeding success. Breeding success differed across three population categories defined by varying levels of human disturbance: island populations, protected mainland populations, and unprotected mainland populations. Differences in breeding success between island populations and protected mainland populations were likely due to differing exposure to predators; however, differences between protected and unprotected mainland populations were unlikely caused by this as both experience equivalent predation levels (although from different predators). Protection only improved the breeding success of oystercatchers in very high-quality habitats (with a high biomass of alien mussels), and where populations were ‘released’ from high levels of human disturbance. In unprotected mainland areas, human activity impacted on the breeding success of local populations primarily through predation of small chicks by uncontrolled dogs, and by rising tides drowning chicks that were hiding from human disturbance. The findings of this study note the potential conservation dilemma resulting from an invasive species improving the conservation status of a Red-listed species, and encourage the implementation of restricted sites in high-quality habitats with high breeding pair densities. 相似文献
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2018年以来国内报道人感染伪狂犬病病毒23例,其中20例患者与生猪养殖及加工相关。我国是养猪大国,庞大的从业人数遇上猪群伪狂犬病病毒变异株流行是巨大的公共卫生隐患。科学认识伪狂犬病感染人的风险,坚定地落实猪群伪狂犬病净化在Covid-19背景下意义重大。 相似文献
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无论在国内还是国外,动物园或野生动物养殖场在生产过程中,动物伤人等事故都时有发生。相比较而言,野生动物饲养展出业是一种面临着较大危险源的职业。本文通过对国内外动物园或野生动物养殖场发生的一些动物伤人事故案例进行分析研究后,发现在许多事故中,人往往既是事故的受害者,同时又是事故的肇事者,无论是因为设施的缺陷,还是因为动物处于危险状态,还是因为人的疏忽,都是由于人的不安全行为激发了事故隐患,导致了事故的发生。本文认为,提高人的安全行为能力,是野生动物饲养与展出安全管理的重要工作。人的安全行为能力,包括对事故发生的预见性行为能力,对安全生产的掌控性行为能力和对危机的应对性行为能力。 相似文献
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L C Leigh 《Research in veterinary science》1978,24(2):205-213
A high incidence of proliferative renal glomerular lesions was found in sows from a breeding herd. All the sows had a very similar lesion, which was characterised by swelling of endothelial cells, with varying degrees of obstruction of the capillary lumina, and an increase in the number of mesangial cells. By differential diagnosis the condition was found to conform most closely with the renal lesion of human pregnancy toxaemia (pre-eclampsia syndrome). It is suggested that this nephropathy may play a part in limiting the useful breeding life of affected sows. 相似文献
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Beta-casein A1 protein variant might be one of the risk factors in the etiology of human disorders like diabetes and ischemic heart disease. However, from the practical perspective selecting for the A2 allele in dairy cattle requires knowledge of whether the A1/A2 polymorphism is associated with breeding values for production traits. A DNA fragment containing A1/A2 polymorphic region was amplified and genotyped using the PCR-ACRS (Amplification Created Restriction Site) technique in 478 Holstein–Friesian bulls yielding the allele frequencies of 0.35 and 0.65 for the A1 and the A2 variants, respectively. A linear regression model was used for testing the association between the polymorphism and breeding values for production traits and showed that the allele coding the A2 protein variant increases breeding values for milk and protein yield and decreases breeding values for fat percentage in milk. Genotyping A.I. bulls at beta-casein locus and preferring A2 allele may lead to two benefits: increasing breeding value for protein yield and decreasing frequency of A1 protein variant, being considered as risk factor for human health. 相似文献
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C. Q. Huang Y. Y. Lin A. L. Dai X. H. Li X. Y. Yang Z. G. Yuan X. Q. Zhu 《Tropical animal health and production》2010,42(1):115-118
The objective of the present investigation was to estimate the seroprevalence T. gondii infection in breeding sows in Western Fujian Province, the People’s Republic of China. Sera collected from breeding sows
during 2006–2007 from 6 different regions in Western Fujian Province were assayed for antibodies to T. gondii by an indirect hemagglutination antibody (IHA) test. Antibodies to T. gondii were detected in 87 (14.38%) of 605 breeding sows. Differences in seroprevalence were observed between sampling regions,
ranging from 10.14% to 37.50%. The present investigation demonstrated that the prevalence of T. gondii infection in breeding sows in Fujian Province was high. Integrated control strategies and measures should be implemented
to prevent and control T. gondii infection in breeding sows, which in turn will have significant implications for the control of human infection with T. gondii in this province. 相似文献
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数量遗传学经过近 1 0 0年的发展 ,形成了一整套理论体系 ,其基本原理和方法已经发展成为动物育种学、植物育种学、人类遗传学和进化遗传学等四个相对独立的分支领域 ,然而这些领域之间的信息交流相当薄弱。在基因组学时代 ,随着对数量性状基因型的识别 ,人们通过对经典数量遗传学模型的修改 ,数量遗传学为分析表型信息和基因型信息提供了合理框架 ,数量遗传学将会比过去发挥更大的作用。讨论了一些在数量遗传学的各个分支领域发展起来的研究方法 ,动物育种工作者亟需广泛了解这些方法 ,为利用更加准确和复杂的模型来分析数量性状并指导动物育种创造条件 相似文献
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1993年11月至1994年2月对南极长城站及其周围地区的巨鹱的分布和数量进行了调查,结果表明巨鹱(Macronectesgiganteus)在研究区内呈不均匀分布;调查期间共发现繁殖群体64个,繁殖鸟222对,繁殖种群数量估计在300对左右;种群的繁殖成功率为37.39%;人类活动对巨鹱的分布和繁殖成功率都有显著影响。 相似文献