反季节种鹅休产期的饲养管理

扬州鹅有明显的繁殖和生产季节性,具体表现为每年9月份进入繁殖产蛋期,至次年5月底停止产蛋进入休产期,6～8月炎热季节基本不产蛋繁殖。这种明显的季节性繁殖造成了雏鹅及肉鹅的市场价格在7～10月份较高。而冬季1～2月份雏鹅上市高峰期也与中国传统的农村春节休闲时节重叠,农户养鹅积极性下降,     

种鹅夏季产蛋技术的探索

<正>鹅的繁殖和生产有明显季节性,每年9月份进入繁殖产蛋期,至次年5月底停止产蛋,进入休产期,6—8月份炎热季节基本不产蛋繁殖。这种明显的季节性繁殖造成了雏鹅及肉鹅的市场价格在7—10月份较高。而冬季1—2月份雏鹅上市高峰期与中国传统的春节重叠,加之牧草短缺,农户养鹅积极性下降,雏鹅供过于求;因此,只有根据市场价格变化规律,在     

种鹅夏季产蛋技术的探索

鹅有明显的繁殖和生产季节性,每年9月份进入繁殖产蛋期,至次年5月底停止产蛋,进入休产期,6-8月炎热季节基本不产蛋繁殖。这种明显的季节性繁殖造成了雏鹅及肉鹅的市场价格在7-10月份较高。而冬季1-2月份雏鹅上市高峰期与中国传统的春节休闲时节重叠,牧草短缺,农户养鹅积极性下降,雏鹅供过于求;只有根据市场价格变化规律,在夏季鹅苗价格高的时候,生产销售鹅苗,在冬季肉用鹅价格高时淘汰种鹅上市销售,才能使养殖户获得更好的经济效益。实现其目的方法：在常规饲养的种鹅中适时留苗培育反季节产蛋种鹅。但其饲养管理方式与常规饲养的种鹅有所不同,只有严格控制光照和温度,采用人工换羽和控料技术,才能适时开产,     

南方高山地区种鹅反季节生产的措施与方法

养鹅生产的经济效益较高，当前存在的问题是各地发展商品肉鹅生产的供种不足。出现这一问题的原因：一是鹅的繁殖性能较差。通常繁殖性能较好的鹅种，年产蛋也仅有100个左右，大多数鹅种只有几十个，孵化供种量有限。二是鹅身披羽绒，具有耐寒怕热的天性，当环境温度达到30℃以上时，鹅将停产换羽。因此自然条件下我国南方养鹅，每年6～9月少有鹅苗供种，鹅的繁殖呈现出明显的季节性。由于鹅的季节性繁殖，     

反季节生产技术对广东养鹅业发展的影响

<正>广东省是我国鹅生产和消费大省之一,年出栏肉鹅约4500多万只。同我国许多地方鹅种一样,广东省内4个地方鹅种(马岗鹅、乌鬃鹅、阳江鹅和狮头鹅)的繁殖活动都具有明显季节性,繁殖期从每年7—8月份开始,到次年3—4月份结束。     

鹅繁殖季节的调控和配套技术

我国南北各鹅种的季节性繁殖现象可分为3种类型,即完全长日照繁殖型、部分长日期繁殖型和短日照繁殖期.鹅繁殖季节性的差异受外界光照周期变化的影响,光照影响垂体促性腺激素和催乳素的分泌水平从而调节年度繁殖产蛋季节.通过遗传选育和其他畜牧生产管理技术如雏鹅的留种季节和营养供应水平等,都能部分影响鹅的繁殖季节性.而通过人工控制程序,则可以完全克服鹅的繁殖季节性问题,并配之以环境控制和营养调控技术,以有效避免热应激和水体细菌和内毒素污染等问题.通过调控种鹅在春夏季的非繁殖季节正常产蛋繁殖,开展鹅的反季节生产,从而克服雏鹅生产的季节性进行肉鹅的全年均衡生产.     

鹅季节性繁殖调控技术的研究开发和展望

广东省的4个灰鹅品种,即体型较大的狮头鹅、中型的马岗鹅,以及小型的乌鬃鹅和阳江鹅,其繁殖活动或性能的一大特点是具有明显的繁殖季节性,表现为从每年的7～8月份进入繁殖产蛋期,至次年的3～4月份进入休产期,全年的产蛋高峰出现于12月至来年1月份。由于鹅的季节性繁殖活动变化,     

鹅反季节调控技术

鹅的季节性产蛋造成雏鹅和肉鹅的季节性供应或断档问题是开展全年均衡商业化生产的障碍。但肉鹅生产和供应的季节性断档,则也创造了其高企的市场价格。因此,业内为了均衡全年鹅生产以及鹅产品的屠宰加工,同时为     

不同孵化方式对马岗鹅种蛋孵化率的影响

鹅具有明显的季节性繁殖特点,同时鹅虽经过人类的长期选育,但就巢的行为仍保持至今。鹅繁殖活动的季节性和强烈的就巢性导致产蛋时间短、产蛋少,进而造成雏鹅及肉鹅的供应也呈现明显的季节性变化,市场价格波动较大。所以,在种鹅产蛋量提高有限的条件下,如何提高种蛋的孵化率显得尤     

鹅反季节繁殖技术要点

我国是世界最大的养鹅大国，年出栏肉鹅5．06亿羽，占全世界鹅出栏总数的92．8％。鹅是典型的季节性繁殖动物，一直以来，鹅的季节性繁殖向题困扰和制约了养鹅生产和产业化发展。为解决这一问题，国内一些单位从20世纪80年代就研究和尝试过种鹅的反季节繁殖。经过多年实践，广东、四川省成功通过光照和营养调控等措施，克服了鹅的季节性繁殖问题。但由于我国地域辽阔，     

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 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.

     

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 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 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 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.