保持蛋鸡夏季高产的技术措施

夏季高温炎热，影响蛋鸡来食和产蛋．为使产蛋鸡在夏季保持较高的生产性能，应加强饲养管理．1提高营养水平夏季当环境温度超过25℃时，为减少自身的产热量，鸡对能量饲料的采食量降低，使其它营养物质的摄取量也相应减少，导致蛋鸡产蛋性能下降，这就需要较高营养水平日粮补偿．1．1日粮中添加1％～2％的油脂，代替碳水化合物为能量补充．1．2注意氨基酸平衡，适当增加日粮中可消化粗蛋白的含量，使氨基酸的利用率不断提高．1．3提高配合饲料中的能量水平，采用代谢能为11·9～12．3MJ／kg的口粮．2调往唱料时间夏季早晚气温较低，蛋鸡采…     

鸡的蛋白质需求量及其确定

鸡对蛋白质的需要量是根据鸡的饲养标准规定的营养指标确定的，但是，无论采用哪一种饲养标准，都只能作为参考，重点还应考虑以下几种因素。能且与蛋白质的比例一般要求高能量必须附以高蛋白，也就是说，日粮中能量与蛋白质的比率应与生产状况相适应。比如1994年6月28日至1994年11月14日在阳谷饲料厂鸡场进行了不同能量、蛋白日粮育成海兰白蛋鸡试验，参照国家蛋鸡营养标准和海兰白品种鸡营养需要，确定育雏、育成两个阶段能量、蛋白水平，并制定相应饲料配方。根据海兰白蛋鸡的生长发育特点，将试验分为0～8周龄（育雏）和9～20周龄（育成…     

第九版NRC鸡营养需要的评述

美国全国科学研究委员会(NRC)1994年2月公布了第九版家禽营养需要量。现将新版NRC与1984年第八版NRC相比,对鸡营养需要方面的调整、为制订营养需要量的研究所取得的进展作如下介绍。本文主要是对蛋鸡和肉鸡的营养需要量参数的分析。 1 蛋鸡的营养需要量参数分析     

确定鸡对蛋白质的需要量的因素

鸡对蛋白质的需要量，一般是根据鸡的营养标准来确定的，但是无论采用哪一种营养标准，只能作为参考，还应根据以下各种因素来确定。　　1.日粮中粗蛋白质的品质:动物对蛋白质比例适当各种必需氨基酸平衡的日粮利用率高，相反，则利用率低，而且用量要增多。　　2.能量与蛋白质的比例：日粮中能量与蛋白质的比例应与生产状况相适应，如高能量需要高蛋白。　　3.品种类型：品种不同生产性能也不完全相同，对蛋白质的需要量也不同。如高能量、高蛋白的日粮，对蛋用品种鸡能保持较高的产蛋率，对肉用仔鸡品种可以获得较大的增重。但是对于其他…     

蛋鸡常用饲料氨基酸有效率测定

研究表明 ,以可利用氨基酸为基础制定蛋鸡营养需要和设计日粮配方 ,不仅可使日粮氨基酸更趋向平衡 ,提高鸡的生产性能 ,而且能充分利用廉价的非常规蛋白质饲料 ,降低成本 ,提高养鸡生产经济效益。国内外学者对此进行了大量研究工作 ,法国罗纳普朗克动物营养公司 (现为安迪苏公司 )应用去盲肠鸡测定了饲料氨基酸真消化率 ,并提出了鸡可消化氨基酸推荐量。我国在这方面也做了研究 ,并取得了一些进展 ,但尚未达成一致的结论。为此 ,我们采用不去盲肠的真代谢能(ＴＭＥ)法对山东省 1 3种蛋鸡常用饲料进行了氨基酸有效率测定 ,供同行参考。1　材…     

缓解蛋鸡热应激的营养措施

产蛋鸡适宜的环境温度为18～25℃，在此温度范围内，蛋鸡表现出最佳的生产性能。而夏季的高温常常引起蛋鸡热应激综合症的发生，对其生理生化、行为、采食及生产性能产生一系列不良影响，导致蛋鸡产蛋率下降，饲料利用率降低，发病率和死亡率升高，严重影响蛋鸡业的发展。如何提高蛋鸡的抗热应激能力，克服夏季高温对蛋鸡带来的有害影响，已成为国内外学者研究的热点之一。本文着重从以下几个方面来讨论热应激对蛋鸡的影响及其营养缓解措施。1 热应激对蛋鸡的影响1.1 热应激对蛋鸡生理的影响1.1.1 当外界温度超过正常体温时，鸡体温度随环境…     

合理使用钙磷，确保鸡群健康

1鸡对钙磷的需求量 　　鸡对钙磷的需求量与鸡的品种，生长期，产蛋，钙磷比例，维生素 D3浓度，植酸磷比例，环境温度和饲料能量密度等因素有关。 1.1鸡品种 　　虽然不同的品种对钙磷的要求不同，各育种公司提供的饲养指南上都有营养标准可供参考，但制定新品种的饲养标准需要经过大量饲养实验来进行。由于品种在不断选育和改良，因此钙磷的推荐需要量也要修订。但某些商业品种的饲养标准并非经过大量饲养实验而得出，仅仅是估计的新的需要量，这一点要特别强调。 1.2生长期 　　育雏、育成、产蛋期鸡对钙磷的需求量不同，因此生产中常常…     

蛋鸡的氨基酸需要

不断研究蛋鸡的营养需要量、科学合理地配制日粮对充分发挥蛋鸡的遗传潜力、提高蛋鸡的生产性能具有重要意义。蛋鸡蛋白质营养需要经历了粗蛋白质(CP)、可消化粗蛋白质(DCP)、总氨基酸(TAA)、可消化氨基酸(DAA)的发展阶段。本文着重综述了影响蛋鸡氨基酸需要量的因素、理想氨基酸模式的应用以及可消化氨基酸方面的一些研究。     

蛋鸡开产前培育指标及营养需要

蛋鸡开产前培育出具有高产、高效生产潜力的青年鸡，关系到养鸡场（户）整个产蛋期的产蛋率和生产性能及其经济效益。本文根据规模化蛋鸡养殖场生产记录资料，结合国内外相关文献报道，分析了不同品种蛋鸡开产前不同阶段的营养需要，提出开产前培育胫长(跖长)、体重、胸肌指数、均匀度核心指标达标的青年鸡的有效措施。     

秋冬季节蛋鸡饲粮的调整

进入秋冬季节，气温逐渐降低，蛋鸡的营养需要也随之发生变化，从而引起采食量增加。蛋鸡的这对自我调节能力是有限的，超出调节能力时，引起生产性能下降。不仅如此，就采食量而言，会引起某些营养摄入相对过剩，造成浪费和其他问题。因此，进入秋冬季节，气温发生大幅度变动时，应对饲粮进行必要的调整。 一．调整方法 气温降低，鸡对能量的需要增加。此时，饲粮能量水平是影响生产性能和采食量的主要因素。要保证蛋鸡的营养需要，维持较佳的生产性能，必须使饲粮的能量水平保持在合理的范围。一般高产蛋鸡，秋季饲粮能量水平在１１．７２…     

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.