养猪生产中严防霉菌毒素中毒

1危害养猪生产的霉菌毒素霉菌毒素是一些霉菌的二级代谢产物,饲料霉菌毒素的产生有两种途径:一种是在田间产生的,另一种是在仓储过程中产生的。直接危害养猪生产的霉菌毒素主要有以下几种:1.1田间霉菌毒素田间霉菌即野外菌株,主要有镰刀菌     

霉菌毒素和吸附剂

霉菌毒素是普遍存在的,是有害的真菌代谢产物,霉菌毒素可在田间收割前就形成,也可形成于收割后的不良储存条件之下。畜禽吃下霉菌毒素,其生产性能就会下降、体内新陈代谢也会发生改变,可能会造成动物和人的病理状态———霉菌毒素中毒。多种产霉菌毒素的真菌都会导致霉菌毒素污     

霉菌毒素吸附剂在养猪生产中的应用

霉菌毒素是霉菌的次生代谢产物。饲料受到霉菌毒素污染后,可能导致畜禽生产性能下降。免疫功能抑制和繁殖机能障碍,甚至引起动物中毒死亡。饲料中使用霉菌毒素吸附剂是减小霉菌毒素污染的有效办法。综述了饲料中霉菌毒素的种类和毒性,霉菌毒素吸附剂的类型和效果,以及新型霉菌毒素吸附剂—霉特吸的特色,为养猪生产中合理选用霉菌毒素吸附剂提供参考依据。     

霉菌毒素造成经济损失：霉菌毒素结合剂的成本与效益评定

家禽饲料配方师在决定使用某种添加剂时,包括霉菌毒素吸附剂,必须要做出评断,使用该种添加剂后,是否能得到比其成本高得多的经济效益,即我们通常说的效益与成本比。 我们在饲料中使用霉菌毒素结合剂,如酯化葡配甘露聚糖有许多原因。通常是因为日常的试验室检测工作发现了饲料或原料中有霉菌毒素存在。但有时不一定能检测出。这可能是由于抽样误差或某些霉菌毒素测定方法的灵敏度,或由于影响家禽的霉菌毒素-黄曲霉毒素,镰刀菌毒     

饲料霉菌毒素对奶牛的毒害作用

据估计全世界供应的谷物中有25％受到霉菌毒素污染,发霉饲料和霉菌毒素中毒是世界范围内奶牛生产中普遍存在的严重问题,饲料中自然产生的毒素污染会影响动物生产性能和健康,霉菌毒素是某些霉菌在饲料基质上生长繁殖过程中产生的有毒二次代谢产物,毒素可在谷物的生长过程、饲料制造、贮存及运输过程中产生。普遍存在于奶牛饲料中的霉菌毒素进人奶牛体内发挥生物学效应,影响奶牛生产性能,造成奶牛养殖业的经济损失,有效地减少饲料中的霉菌毒素对于获得高产是非常关键的。     

霉菌毒素的研究进展

霉菌毒素是霉菌在生长繁殖过程中产生的有毒次级代谢产物,在饲料中广泛存在,主要包括黄曲霉毒素、赭曲霉毒素、烟曲霉毒素、玉米赤霉烯酮、单端孢霉菌素等。目前,关于单一霉菌毒素的毒性研究报道较多,而对多种霉菌毒素的联合毒性进行探索将是今后霉菌毒素研究的热点。     

饲料中霉菌毒素对猪生产繁殖的影响

霉菌毒素在饲料中很常见,母猪对霉菌毒素高度易感。摄入含有霉菌毒素的饲料之后会对母猪的生育繁殖造成较大影响,引起多种症状。影响的严重程度往往同霉菌毒素的种类、含量以及母猪的健康状态等有关。常见的霉菌毒素有黄曲霉毒素、麦角生物碱、单端抱霉烯族毒素以及玉米赤霉烯酮等。     

甘露聚糖作为霉菌毒素吸附剂的研究进展

霉菌毒素是霉菌的代谢次生物，饲料中的霉菌毒素对人、畜健康构成了威胁。就甘露聚糖对霉菌吸附效果等方面研究作一综述，为绿色饲料添加剂的开发提供新的思路和方向。     

猪霉菌毒素中毒及防控措施

饲料中的霉菌毒素是引发猪饲料中毒的主要原因之一,严重影响着猪的生长发育、母猪生产、繁殖性能以及仔猪的成活率,还可以引起免疫抑制,使猪的抵抗力下降,诱发多种疾病,甚至引起死亡。残留于猪肌肉、内脏中的霉菌毒素还可能通过食物链传递给人,造成更大的危害。因此,饲料霉菌毒素对养猪生产的危害应引起养殖者的重视。目前饲料检测到的毒素已超过350种,饲料中各种霉菌毒素之间有协同作用,猪采食了由霉菌毒素污染的饲料,引发抵抗力下降,继而容易继发各种传染病。     

饲料和饲草中霉菌毒素对动物生产性能的威胁

霉菌毒素是由真菌所产生的代谢产物，当采食生物显著量时，它对动物是有毒的，因此而得的疾病叫霉菌毒素中毒症。饲料谷物中霉菌的生长和霉菌毒素的产生受到许多因素的影响，但水分是最重要的因素。谷物贮存时，水分应保持在１５％以最大限度地抑制霉菌的生长。最普通的、最被人们所认识的、自由繁殖的霉菌毒素是黄曲霉毒素和镰刀菌霉菌毒素。饲草也可能含有复合的真菌生物碱。我们对黄曲霉毒素中毒症病因学的理解远远比对镰刀菌霉菌毒素中毒症的病因学了解得多。对因采食霉菌毒素污染的饲草而导致的中毒症的病因学更了解甚少。这可能是因为…     

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.