奶牛早期妊娠诊断研究进展

奶牛配种(或受精)后不久,必须进行早期妊娠诊断,以便加强怀孕母牛饲养管理,保证顺利分娩或对未孕母牛及时配种,缩短产仔间隔,提高繁殖效率。生产实践中广泛应用的是直肠检查等方法,尽管此法简单易行,不     

母牛妊娠诊断的“四诊”法

1问诊配种日期和配种次数。询问母牛何时开始发情,何时配种、人工授精或本交,以往妊娠配种次数,本次配种次数,最后一次是何时配种的。询问这些项目可以大致判定母牛是否已到检查时间和采用何种方法合适。最后一次配种后是否再发情。妊娠最早的症状是发情停止,如果饲养员观察牛群非常仔细,此种方     

浅谈母牛不育症的发病原因及综合防制措施

1 母牛不育症的定义 母牛不育是母牛暂时或永久性的不能繁殖,它是由于母牛的饲养、管理、利用和配种不当、生殖器官的疾病和反常和其他器官或全身疾病以及衰老等引起的.严格说来,凡是在母牛成熟后或分娩之后超过了正常发情时间仍不能配种受孕的母牛以及经过多次配种仍不能受孕的母牛,都可以视作不育.     

提高奶牛生产效益100例（连载）

44.抓住奶牛发情时机,做到适时配种 适时配种包括:育成母牛配种年龄要适时;母牛发情持续期内配种要适时;母牛产后配种时间要适时;配种季节要适时。实践证明,凡是奶牛配种做到四个适时的奶牛场(户)都会得到良好的经济效益。     

牛的春繁技术七问

一问:怎样知道母牛怀孕了?答:母牛配种后,不再表现发情,性情温驯,食欲增强,膘肥毛亮,一般即可认定怀孕了。如阴道检查,母牛配种后一个月,当开膣器插入阴道时,阻力明显,有干涩感,阴道黏膜苍白,无光泽,子宫口偏向一侧,呈闭锁状态,上面为灰暗浓稠的黏液塞所封固,即为怀孕;如母牛配种后20天,应用己烯雌酚注射剂10mg,一次肌肉注射,孕牛无发情表现,未孕母牛第2天明显发情。如直肠检查、隔肠抚摸子宫无反应;或右子宫角有收缩,孕角略大于空角,这是母牛已怀孕1个月;如子宫角变得短粗,象电筒头粗,柔软如水袋,卵巢内存有明显的黄体,这是怀孕40～50天;若…     

母牛的人工授精技术

母牛发情后采用自然交配的方式,往往受胎率较低,因此在实际生产中常常采用人工授精技术来有效提高母牛繁殖力。为此,技术人员必须仔细观察母牛发情时间,准确掌握母牛配种时机,熟练掌握人工授精技术,防止母牛“配种晚或配不准”的问题出现,做到适时输精、配种,达到提高母牛繁殖力的目的。     

母牛的妊娠诊断

母牛在人工授精或自然交配以后 ,人们最关心的问题是 :母牛到底怀孕了没有 ?妊娠诊断是确定母畜是否妊娠。如已妊娠 ,则应加强饲养管理 ,保证胎儿正常发育与分娩。如果没有妊娠 ,则应密切注意其下次发情 ,抓好再配种工作 ,并及时找出其未孕的原因 ,例如交配时间和配种方法是否合适 ,公畜精液品质是否合格 ,生殖器官是否患病等等 ,以便在下次配种时作必要的改进或及时治疗。妊娠诊断不但要求准确 ,而且要求能在早期确诊。目前母牛妊娠诊断的方法很多 ,下面笔者介绍几种方法并作一些评价。1　外部征状观察法母牛妊娠以后 ,一般表现为周期发情…     

母牛妊娠诊断

母牛配种后,应能尽早进行妊娠诊断,可以止母牛空怀,提高繁殖力。对未受胎的母牛,应及补配;对已受胎的母牛,须加强饲养管理,做好保工作。     

胎衣滞留时间及其对奶牛产后生育力的影响

通过对1,111头初产母牛和2,493头经产母牛泌乳期资料分析,了解胎衣不下对母牛产后生育力的影响,母牛分别按是否伴有子宫炎和(或)卵巢囊肿进行分组,以比较不同胎次和疾病可能对生育力的影响。患子宫炎和卵巢囊肿的母牛,其胎衣滞留时间长短对生育力没有影响。单纯胎衣不下的初产母牛第一次配种受胎率降低;经产母牛如果胎衣滞留超过5天,其第一次配种受胎率也明显降低;如果胎衣滞留超过7天,第一次配种时间延迟18天,受胎的时间延迟57天。     

母牛妊娠诊断

母牛配种后,应能尽早进行妊娠诊断,可以防止母牛空怀,提高繁殖力.对未受胎的母牛,应及时补配;对已受胎的母牛,须加强饲养管理,做好保胎工作.     

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 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 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 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.