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1.
<正>大量研究表明,脂溶性维生素A、D、E、K对动物的骨骼发育有明显的影响。Aburto等(1998)研究报道,过量维生素A显著降低了骨灰分和增加了软骨病 相似文献
2.
维生素A是肉仔鸡生长发育过程中不可缺少的微量元素之一,过量和缺乏都影响肉仔鸡的生长发育。文章综述了维生素A的来源与代谢、影响维生素A代谢的因素及维生素A的缺乏症和中毒症,提出了维生素A在肉仔鸡日粮中的需要量及研究进展,以便为科学饲养肉仔鸡提供理论依据。 相似文献
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本试验选用艾维茵肉仔鸡作为试验动物，以玉米和大豆粕为主要原料配制基础日粮，采用二因子多水平试验设计，探讨在实用日粮条件下锌缺乏和锌过量对肉仔鸡维生素A代谢的影响，从而进一步研究影响维生素A代谢的临界低锌和高锌浓度，揭示肉仔鸡体内锌与维生素A代谢的相互关系，进而探讨锌与维生素A对肉仔鸡生产性能的影响。 相似文献
4.
本试验选用艾维茵肉仔鸡作为试验动物,以玉米和大豆粕为主要原料配制基础日粮,采用二因子多水平试验设计,探讨在实用日粮条件下锌缺乏和锌过量对肉仔鸡维生素A代谢的影响,从而进一步研究影响维生素A代谢的临界低锌和高锌浓度,揭示肉仔鸡体内锌与维生素A代谢的相互关系,进而探讨锌与维生素A对肉仔鸡生产性能的影响. 相似文献
5.
维生素A参与动物视色素的正常代谢及骨骼的生长，维持上皮组织的完整性以及正常的繁殖机能，在动物体内具有重要的生理功能。本病是由于维生素A缺乏而引起的慢性营养代谢病。 相似文献
6.
正一、维生素A的缺乏与应用维生素A易从胃肠道吸收。胆汁和一些脂溶性物质可促进其吸收。维生素A与视觉、上皮组织、生殖功能、骨骼生长、免疫功能有关。其能维持正常的视觉功能;维持皮肤、粘膜和上皮组织的完整性,能促进动物生长发育,维持骨骼正常发育。通过调节三大物质代谢,增加免疫球蛋白生成,促进器官组织正常生长和代谢等作用;促进类固醇激素的合成。当维生素A缺乏时可引起 相似文献
7.
维生素A参与动物视色素的正常代谢及骨骼的生长,维持上皮组织的完整性以及正常的繁殖机能,在动物体内具有重要的生理功能。本病是由于维生素A缺乏而引起的慢性营养代谢病。 相似文献
8.
维生素A参与动物视色素的正常代谢及骨骼的生长,维持上皮组织的完整性及正常的繁殖机能,在动物体内具有重要的生理功能。本病是由于维生素A缺乏而引起的慢性营养代谢病,以生长发育不良、视觉障碍、神经症状及器官黏膜损害为特征。1猪维生素A缺乏 相似文献
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一、维生素A缺乏症维生素A缺乏症是由于维生素A缺乏而引起的,以夜盲、上皮细胞变性、萎缩、角化和骨骼发育不良为特征的一种营养代谢病。家禽对维生素A缺乏较为敏感,幼禽贮存维生素A的能力比成年禽低得多,因此,幼禽更易发生维生素A缺乏症。1.病因。长时期使用胡萝卜素或维生素A含量过低的饲料喂家禽, 相似文献
10.
一、维生素A缺乏症维生素A缺乏症是由于维生素A缺乏而引起的,以夜盲、上皮细胞变性、萎缩、角化和骨骼发育不良为特征的一种营养代谢病。家禽对维生素A缺乏较为敏感,幼禽贮存维生素A的能力比成年禽低得多,因此,幼禽更易发生维生素A缺乏症。1.病因。长时期使用胡萝卜素或维生素A含量过低的饲料喂家禽, 相似文献
11.
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. 相似文献
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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. 相似文献
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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%). 相似文献
15.
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. 相似文献
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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. 相似文献
18.
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. 相似文献
19.
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%). 相似文献
20.
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. 相似文献
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