哺乳动物性别控制和鉴定技术的研究进展

文章对哺乳动物性别决定机理、受精前的性别控制技术、受精后的胚胎性别鉴定技术以及今后性别控制技术的前景和趋势等方面进行了综述。     

鸡胚性别鉴定研究进展

家禽性别控制研究包括性别决定、性别分化、性别鉴定、性别诱导和性别控制等方面。性别决定与分化本质的发现是家禽性别研究的重要基础，对鸡胚性别的早期鉴定是对性腺基因研究的重要内容。     

家畜性别控制的研究进展

对家畜性别决定机理、受精前的性别控制技术、受精后的胚胎性别鉴定技术以及今后性别控制技术的前景和趋势等方面进行了分析讨论,旨在为科研工作者和畜牧生产者提供参考.     

鸡及鸡胚性别鉴别方法

家畜的性别控制技术对提高畜牧业生产水平和经济效益具有重要意义,也是畜牧界数十年来研究的热点之一。然而,家禽的性别控制和性别鉴别远比家畜复杂,在家禽生产中伴性遗传和泄殖腔鉴别法仍然是性别鉴定的主要方法。随着性别控制理论和试验研究的进展,目前产生了多种方法对家禽胚胎的进行性别鉴别。如何尽早的鉴别出鸡胚的性别是研究的重点之一。本文就近年来产生的鸡胚性别鉴别的主要方法作一综述。     

性别控制技术的研究与应用进展

性别控制指通过人为干预使动物的繁育按照人们所希望的性别繁殖后代的技术.随着畜牧业生产智能化的迅速发展,高效准确的性别调控技术成为提高畜禽生产经济效益的重要研究方向.本文主要综述了性别分化调控、性别反转和X、Y精子分离技术,以期促进畜牧业养殖性别控制技术的发展和应用.     

家畜性别鉴定与性别控制技术在猪育种中的应用

简介了胚胎性别的鉴定和采用X精子与Y精子分离的性别控制技术在猪育种中的应用。     

家畜胚胎性别鉴定的分子生物学方法及现状

家畜胚胎的早期性别鉴定技术是家畜性别控制技术的一个重要途径,也是家畜胚胎移殖技术的一项重要内容,随着胚胎冷冻,切割及核移殖技术等的发展,家畜的性别控制技术愈来愈显得重要。它一直是畜牧生产和科研关注的热点。本文就家畜胚胎性别鉴定的意义、分子生物学方法及研究现状等方面加以综述。1性别控制的意义通过家畜胚胎早期性别鉴定实现性别控制,一方面能大大提高畜牧业的经济效益、由于人工授精技术的普及,公畜的需要量越来越少。因此,奶牛、奶山羊、犬、兔,都以雌性价值高。而在实际生产中,根据生产的实际需要,也需人为地控…     

鸡的性别决定与性反转

鸡的性别与其生产力关系极大。在蛋类生产中，母鸡的生产效益远高于公鸡，而在肉鸡生产中，公鸡又比母鸡饲料利用率高，生长速度快，生命力强。因而性别控制成为提高养鸡生产效益的一种重要技术途径。长期以来，许多学者和生产者为此而不断努力，对鸡的性别决定与性反转进行了大量的研究和探索，以期实现人为的性别控制，更大限度地提高养鸡业的生产效益。 1鸡的性别决定 　　遗传学研究证实，动物的性别由遗传物质决定。就鸡而言，性别决定机制目前公认的有以下三种学说。 1.1性染色体决定学说 　　1906年 Stevens首次提出了性别决定于性…     

鸡胚性别鉴定“黑科技”

在蛋鸡生产中,不太受欢迎的公鸡在刚出孵时就要被扑杀,这引起了人们对动物福利的关注。现有的鸡胚性别鉴定方法如翻肛鉴别法、鸡胚尿囊液雌激素含量鉴定法等或多或少会对鸡胚孵化率及健雏率产生影响。因此,期望找到一种无损且高效的早期鸡胚性别鉴定方法,以满足现代集约化孵化场的需求。近年来,一种基于羽毛颜色检测的非破坏性光学技术被提出,用于无损鉴定鸡胚性别。由于褐色鸡品系在羽毛颜色上表现出性别二态性,雌性日龄雏鸡羽毛表现为褐色,雄性表现为黄色。该技术利用卤素灯对11~14日龄的鸡胚进行透光检查,形成的透射光被光谱范围在400~1000nm的高光谱相机采集,随后采用主成分分析、线性判别分析等方法对数据进行分析和分类。研究表明,对孵化14d的鸡胚性别鉴定时准确率最高,接近97%。     

鸡的性别鉴定技术

家禽的性别与生产有极大的关系,介绍了鸡的性别鉴定技术,包括伴性性状鉴别法、肛门鉴别法、自动鉴别鸡胚、超声波扫描法（US）鉴别鸡胚性别、细胞仪鉴别鸡胚性别、PCR技术鉴别鸡胚性别和核磁共振测定鸡胚性别.     

Heartworm in dogs in Canada in 1984

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.

     

Heartworm in dogs in Canada in 1983

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.

     

Heartworm in dogs in Canada in 1991

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.     

Heartworm in dogs in Canada in 1985

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.

     

Heartworm in dogs in Canada in 1988

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%).     

Heartworm in dogs in Canada in 1989

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.

     

Heartworm in dogs in Canada in 1987

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%).     

Heartworm in dogs in Canada in 1986

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.