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1.
在现代养猪生产实践中,母猪繁殖性状作为重要的经济性状之一,其选育和改善越来越受到人们的重视和关注。因为繁殖性能的优劣通过直接影响母猪繁殖生产力,并间接影响了养猪场的经济利益。其中产仔数作为繁殖性状之一,它的提高无疑会带来巨大的经济效益。随着分子技术在动物育种中的应用,展开了对数量性状相关基因的研究,研究影响窝产仔数的基因也成为了热点之一。目前为止,已经发现很多与猪产仔数有关的主效基因和候选基因,笔者对其进行了综述。 相似文献
2.
猪的大多数繁殖性状的遗传力很低，通过直接选择进展不大。对近年来对母猪繁殖性状杂交利用、直接选择排卵数和产仔数、通过胎盘效率提高产仔数、控制窝产仔数的主效基因的选择进行研究。从目前的研究结果看，基于胎盘效率的选择是提高猪的窝产仔数的有效方法之一；随着分子遗传学技术研究的进展，影响猪繁殖性状的主效基因或QTL的鉴别，使得MAS成为了可能。 相似文献
3.
繁殖是养猪生产过程中的关键一环 ,该环节成功与否直接影响整个养猪业的经济效益。传统数量遗传学在指导家畜育种中起到了重要的作用 ,但是繁殖性状遗传力低、性状表现晚、而且是限性遗传 ,通过常规选择难以有所进展。中国猪 ,尤其是太湖猪 ,以其超高繁殖率闻名于世 ,国内外学者对其高繁殖性能的遗传机制进行了研究 ,提出了窝产仔数主效基因假说 ,并通过候选基因法、基因组扫描法等方法进行了研究 ,期望找到控制产仔数的主基因 ,从而为猪繁殖性状的遗传改良提供了新的途径。目前太湖猪窝产仔数主效基因探索已有成功的报道 ,本文将对猪高繁殖… 相似文献
4.
为了筛选淮南猪产仔数、有效产仔数、窝重等繁殖性状的候选基因及SNP标记，采用GGP porcine50K芯片对254头淮南母猪开展了基因分型和全基因组关联分析。结果显示：在总产仔数、有效产仔数、窝重3个繁殖性状分别发现了31、17、1个SNP和43、20、1个候选基因，筛选了FBXO5、PRDM9、CDT1和PABPN1等作为总产仔数性状候选基因，为后续通过分子育种手段提升淮南猪繁殖性状奠定了基础。 相似文献
5.
母猪的繁殖性能一直是育种工作者关注的焦点之一,如产仔数就是一个重要的经济性状,但产仔数的遗传力很低(约为0.1),通过传统的育种方法对该性状的改良收效甚微。标记辅助选择(marker assited selection,MAS)能在短时间内显著提高低遗传力性状。分子生物技术的快速发展为MAS育种在动物实际育种工作中的应用提供了保障,而且近些年来获得了较好的效果。雌激素受体基因(ESR)和卵泡刺激素β基因(FSHβ)等,是与繁殖性能有关的主效基因。这些主基因在大白、长白、杜洛克、二花脸、东北民猪、金华猪、香猪、荣昌猪、莱芜黑猪等品种中都有相关研… 相似文献
6.
猪的繁殖性状直接反映出猪场的生产水平,也具有重大经济效益.但繁殖性状遗传力较低,整个繁殖的过程也十分复杂,常规的选种育种方法提高猪的繁殖性状难度很大,进展也很缓慢.而选择一些影响猪繁殖性状的基因,将常规的育种方法与分子育种方法相结合加快育种进展,可以快速提升猪的繁殖性能.猪产仔数是猪繁殖性能中最为重要的性状.本文主要综... 相似文献
7.
催乳素受体(PRLR)通过与催乳素结合,介导包括动物泌乳和繁殖在内的多种生理功能。近年来,PRLR基因作为猪产仔数候选基因,国内外对其开展了广泛的研究。该文综述了PRLR基因多态性及其与猪繁殖性能的相关性,重点讨论了PRLR基因多态性对猪产仔数的影响,并对PRLR基因研究中存在的问题进行了分析,为进一步阐明其遗传机理,以及为采用候选基因法寻找猪重要经济性状的遗传标记提供参考。 相似文献
8.
猪的产仔数是繁殖性状中重要的经济性状,直接关系到养猪业的经济收益。英国动物育种学家Chris Haley曾估算,如果每头母猪的产活仔数每胎提高I头,英国的养猪业每年就可增加利润7亿英镑,整个欧盟养猪业可多获利20亿英磅。在我国,如果母猪产仔数每胎提高1头,每年也将增收190亿人民币的纯利。因此,通过候选基因法寻找控制猪产仔数的主效基因或遗传标记,以及通过标记辅助选择提高猪的产仔性能,是目前猪遗传育种研究的热点之一。在过去的半个世纪里,通过常规育种技术,猪的许多重要生产性状都在遗传上得到了很好的改良（如瘦肉率,背膘厚）,但对产仔数的改变却十分有限,主要原因是产仔数的遗传力很低,同时又是限性表达性状。但不同品系,窝产仔数的变化范围在2～20头,平均为9～10头;其表型标准差在2．5～3头之间;遗传力在0．1～0．15之间。因此,通过猪育种手段（MAS）提高猪产仔数还有相当大的空间。 相似文献
9.
在猪育种中选择性状的确定有以下几点考虑：首先应与目标性状有紧密的遗传相关，其 次选择性状应有较大的表型和遗传变异且有较完整准确的遗传参数估计值，第三性状应能准 确方便地度量。随着猪育种的逐渐深入，一些性状的改良已达最适水平，如何进一步确定和 发现新的选择性状进一步提高猪的质量为育种者所追求的目标。性状测定手段的进步为我们 寻找新的选择性状提供了条件。本文主要对近年来对猪的育种中所涉及的目标性状和选拔性 状的研究进展做一简要综述。 1 繁殖性状 猪的多产性即窝产仔数，包括总产仔数和产活仔数两性状。从遗传和综合经济效益的高度出 发产仔数是繁殖性状中最重要的性状，另外窝产仔数容易记录，可供利用的遗传变异信息量 大，是繁殖性状中被研究得最多的性状。 近年来，对猪产仔数的选择日益受到重视，其原因在于：①对猪产仔数的遗传特征的了解更 加深入；②猪产仔数期望遗传改进量较大 相似文献
10.
上期回顾:上一期简要介绍了决定梅山猪与欧洲猪种窝产仔数的因素、窝产仔数与相关繁殖性状、采用传统选育与分子遗传学方法提高窝产仔数和与窝产仔数有关的候选基因. 相似文献
11.
In late December 1984, 1853 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1984 and 35% of them responded. Veterinarians reported that 97,794 dogs were blood-tested to check for microfilariae and 1417 dogs (1.45% of those tested) were found with heartworm. Another 34 dogs were amicrofilaremic, but were diagnosed as having heartworm disease, to give the total number diagnosed in 1984 as 1451 (1.48%). Heartworm was reported from all provinces except Prince Edward Island and Newfoundland but most (1310) of the cases were in Ontario. In Quebec, 126 cases were reported mostly from west of Montreal. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 27% of the cases were observed with clinical signs of heartworm disease and 72% had a history of not having left Canada. Southwestern Ontario continued to be the primary focus of the infection. 相似文献
13.
In late December 1983, 2 800 veterinarians across Canada were sent a questionnaire in order to assess the status of heartworm disease in Canada in 1983 and 26% of them responded. Veterinarians reported that 59 504 dogs were blood-tested to check for microfilariae and 771 dogs (1.30% of those tested) were found with Dirofilaria immitis. Heartworm disease was diagnosed in all provinces except New Brunswick and Newfoundland but most (733) of the cases were in Ontario. Heartworm disease was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 31% of the cases were observed with clinical signs of heartworm disease and 64% had a history of not having left Canada. Southwestern Ontario continues to be the focus of the infection and most of the dogs there had not left the province previously. 相似文献
15.
In late November 1991, 1883 clinics in Canada were sent a questionnaire to assess the status of Dirofilaria immitis in dogs in 1991 and there was a 60.0% response. There were 344,031 dogs tested for heart-worm (HW), 627 were found infected and the prevalence of HW infection was 0.18%. There were 417 dogs with HW in Ontario, 116 in Manitoba, 38 in Quebec, 53 in British Columbia, three in Alberta, and one in Nova Scotia. In British Columbia, all of the infected dogs but one were from the Okanagan valley which, as from 1991, is a new focus of infection in Canada. Most dogs with HW had not been on preventive medication in 1990, and the prevalence among dogs tested and unprotected was 0.59%. That prevalence was considerably higher in endemic areas. Companion dogs, over three years of age and maintained primarily outdoors in rural areas, were most frequently infected. One cat was diagnosed with D. immitis and 33 dogs had Dipetalonema reconditium. 相似文献
16.
In late December 1985, 1485 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1985 and 44% of them responded. Veterinarians reported that 137,300 dogs were blood-tested to check for microfilariae and 1210 dogs were found with heartworm. Another 36 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number diagnosed in 1985 as 1247 (0.91%). Heartworm was reported from all provinces except Prince Edward Island, Newfoundland and Saskatchewan but most (1126) of the cases were in Ontario. Southwestern Ontario continued to be the primary focus of the infection in Canada. From Quebec, 91 cases were reported mostly from and around Montreal. From Manitoba, 19 cases were reported from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 28% of the cases were observed with clinical signs of heartworm disease and 78% had a history of not having left Canada. 相似文献
17.
In late November 1988, 1581 small and mixed animal clinics and institutional veterinarians across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1988, and 46% of them responded. Veterinarians reported that 181,577 dogs were blood-tested for heartworm disease and 367 dogs were found with D. immitis microfilariae. Another 60 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1988 as 441 (0.24%). 相似文献
18.
In late November 1989, 1732 clinics and institutional veterinarians were sent a questionnaire to assess the status of Dirofilaria immitis, and 51.7% responded. Of 247,716 dogs tested, 394 had D. immitis microfilariae and 51 were amicrofilaremic for a total of 445 cases and heartworm prevalence of 0.17%. Most (408) of these dogs had no preventive medication and the prevalence among dogs tested and unprotected was 1.01%. That prevalence was considerably higher in endemic areas. Thirty-seven dogs with heartworm had preventive medication. Heartworm was most frequent in companion dogs over three years of age maintained outdoors in rural areas. About 75% of the cases had never left Canada, 26% had clinical signs and 125 were not treated. Heartworm was reported from British Columbia, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland, but 383 cases were in Ontario. South-western Ontario was the primary focus of infection. There were 33 cases in Quebec and 24 in Manitoba, mainly found in and around Metropolitan Montreal and Winnipeg respectively. 相似文献
19.
In late November 1987, 1246 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1987, and 50% of them responded. Veterinarians reported that 165,428 dogs were blood tested for heartworm disease and 511 dogs were found with D. immitis microfilariae. Another 78 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1987 as 589 (0.35%). 相似文献
20.
In late December 1986, 1224 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1986; 46% of them responded. Veterinarians reported that 150,989 dogs were blood-tested for microfilariae and 869 dogs were found with heartworm. Another 65 dogs were amicrofilaremic but diagnosed with heartworm disease and one was found with heartworm at necropsy to give the total number diagnosed in 1986 as 935 (0.62%). Heartworm was reported from Manitoba, New Brunswick, Ontario and Quebec, but most (810) of the cases were from Ontario. South-western Ontario continued to be the primary focus of the infection in Canada. There were 103 cases reported from Quebec, mostly from and around Montreal, and 21 cases from Manitoba, from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 33% of the cases were observed with clinical signs of heartworm disease and 81% had a history of not having left Canada. 相似文献
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