奶牛性控冻精人工授精影响因素研究

用分离X和Y精子的性控精液进行人工授精是控制家畜性别之最简单可行的方法.然而,低密度性控精液输精效果还不如常规人工授精,许多技术环节都有待改进.以常规冻精和稀释常规冻精为对照,研究解冻方法、输精时间和部位、不同精液来源和输精员以及育成和经产牛等因素对性控冻精人工授精妊娠率的影响.结果显示,精液解冻水浴温度和持续时间对人工授精效果有显著影响,性控精液对解冻水浴温度更敏感;性控冻精和稀释常规冻精比常规冻精对输精时间要求更严格;3种精液输精到排卵卵泡同侧子宫角基部受胎率都显著高于输精于子宫体和同侧子宫角前端;3种精液育成牛受胎率(80%)都显著高于经产牛(50%);于输精同时注射促排卵素3号明显提高性控冻精受胎率;经严格挑选、能够从事胚胎移植操作的技术熟练输精员之间性控冻精受胎率差异不显著;在所设计的不同条件下,性控冻精与稀释同样倍数的常规冻精行为相似,说明精子分离过程没有对精子造成特殊损伤.研究结果说明,精确控制人工授精各个技术环节可以实现消除性控与非性控、低密度与高密度精演之间的差别,获得高妊娠率.     

鲜精配种技术在高山细毛羊繁育中的推广应用

本实验旨在扩大良种羊利用率,提高优秀种公羊的配种能力和细毛羊的综合经济效益,通过开展绵羊鲜精大倍稀释配种技术效果试验,结果采用集中采精、大倍稀释、短途运输、分散输精的方法,为我县皇城镇14个村的40个配种站点提供稀释精液43756mL,授配一次发情母羊42059只.经测定,对采用1:8～12的大倍稀释精液,1次/d,输精的情期受胎率达到80.5%,每日2次输精的情期受胎率达到93.8%,达到和超过国内领先水平.     

甘肃高山细毛羊细管鲜精低温保存效果研究

为了研究甘肃高山细毛羊种公羊细管精液低温保存的效果.用葡萄糖、柠檬酸钠、鲜奶和卵黄为主要成分配制了3种稀释液,10倍稀释精液,并在4℃保存,分别在12h,24 h,36h,48 h,60h和72 h观测精子活力和人工授精受胎率.结果显示,配方Ⅲ稀释精液后,细管封装,4℃保存,72 h后精子活力可达0.49,与配方Ⅰ和Ⅱ差异显著,而且配方Ⅲ稀释精液后,在远距离输精后受胎率可达78.3％.以柠檬酸钠和葡萄糖为基础,添加卵黄和TCM199,在4℃下,能有效保护甘肃高山细毛羊精液,延长精子寿命,且在3d内可以满足远距离人工授精要求,有效利用种公羊价值.     

精液剂型、输精部位对母驴情期受胎率的影响

为探索精液剂型、输精部位对母驴情期受胎率的影响,试验在母驴发情旺季(3—6月份)选取健康母驴300头随机分组,分别采用3种精液剂型(冷冻精液、4℃冷却精液、鲜精)和2个不同输精部位(子宫颈内口、子宫角深部)进行人工授精,并对其受孕情况进行统计和分析。结果表明:冷冻精液、4℃冷却精液、鲜精人工授精的情期受胎率分别为23.88%、29.67%、35.28%,其中鲜精受胎率最高,与冷冻精液之间差异显著(P0.05);子宫颈内口和子宫角深部输精的情期受胎率分别为33.33%、45.16%,组间差异不显著(P0.05),但后者的受胎率略高。说明采用鲜精剂型、子宫角深部输精的方式可以更好地提高母驴情期受胎率。     

不同部位输精对母牛受胎率影响的研究

把自然发情的母牛分2组,即冷冻精液组、鲜精组,观察不同部位输精对母牛受胎率的作用及影响.结果表明①冷冻精液组在子宫颈内输精,受胎率黄牛为0,水牛为0;在子宫颈与子宫体交界处输精,受胎率黄牛达86.67%,水牛达66.67%;在子宫体前1/3段输精,受胎率黄牛达60%,水牛达40%;在子宫颈内约5～6 cm输精,受胎率黄牛达26.67%,水牛达6.67%;在子宫体与子宫角交界处输精,受胎率黄牛达13.33%,水牛达6.67%.表明在子宫颈与子宫体交界处输精,受胎率显著高于其他输精部位(P＜0.01);②鲜精组在子宫颈内输精,受胎率黄牛为46.67%,水牛为13.33%;在子宫颈与子宫体交界处输精,受胎率黄牛达80%,水牛达60%;在子宫体前1/3段输精,受胎率黄牛达66.67%,水牛达33.33%;在子宫颈内约5～6 cm输精,受胎率黄牛达33.33%,水牛达20%;在子宫体与子宫角交界处输精,受胎率黄牛达13.33%,水牛达13.33%.表明在子宫颈与子宫体交界处输精,母牛受胎率显著高于其他输精部位(P＜0.01),为母牛冻配的最佳输精部位.     

改进精液处理和输精方法提高种公山羊利用率的研究

对绒山羊公羊精液采用不同稀释液处理,以葡萄糖、柠檬酸钠稀释液效果最好,受胎率达93.55%;精液做1∶4～1∶39倍稀释后输精,1∶4～1∶19倍稀释效果较好,情期受胎率可达88.06%～89.74%;山羊精液经1∶9倍稀释后,输精量0.05～0.15 ml,输入有效精子1 000万～4 000万,对受胎效果影响不大.采用简易输精方法(仿照公羊本交的方式,用输精器将精液直接输入发情母羊的阴道底部),将精液直接输入阴道,与常规方法(用开膣器扩张阴道将输精器插入子宫颈口的输精方法)将精液输入子宫比较,对受胎影响不大,这种方法更适于农村牧区推广应用.     

湖羊冷冻精液的输精效果观察

制作单精(单个公羊的精液)和混精(两个以上公羊的混合精液)两种安瓿冻精,在试验全期对328头母羊采用了混精冻精输精法,对501头母羊采用了单精冻精输精法.结果表明,混精组输精母羊的情期受胎率比单精组提高19.26%.而混精冻精输精和增加一个情期的输精量两种方法,是提高湖羊受胎率的有效方法.     

猪人工授精关键技术

猪的人工授精基本操作流程是采精→精液品质检查→精液稀释→稀释精液的包装→稀释精液的保存→输精。每一个操作细节都有可能影响精液品质,最终影响母猪的情期受胎率。     

马人工授精试验

试验旨在研究马人工授精中子宫角细管输精效果和浓缩精液常温保存及运输方式,验证了传统胶管输精单次追精的结果。结果表明:子宫角细管输精所得受胎率81.08%,与胶管输精所得情期受胎率差异显著(0.01P0.05);15 m L离心管常温保存3 h获得的情期受胎率较高(P0.01);群牧马单次追精情期受胎率53.62%,较多次输精效果差(P0.01)。     

家畜人工授精讲座(连载)——第一讲 为什么要推广家畜人工授精

<正> 一、什么是家畜的人工授精? 人工授精,简而言之,就是用人工方法采某公畜精液,再用人工方法为发情母畜输精。现代人工授精技术还必须对采得的精液的品质进行必要评定,把合乎标准的精液再用合成稀释液进行稀释,稀释后的精液或直接输精或保存备用或运送到远离公畜的地点输精。所以,现代人工授精技术一般都包括采精、精液品质的评定、精液的稀释保存和运输、发情鉴定、输精等技术环节。     

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.