动物营养研究中的若干热点问题

营养与饲料配方技术研究的目标是解决动物对营养物质以及饲料原料合理利用问题。随着动物营养与饲料科学的研究进展以及饲料工业的迅速发展 ,动物生产水平和营养物质利用率有了极大提高。但目前尚还有一些问题值得探讨 ,下面就根据当前我国动物生产和饲料工业的现状 ,谈几点看法。1　应深入研究营养物质之间的相互关系动物营养物质利用的机理已基本清楚 ,营养物质之间的相互关系便成为研究的焦点。经过一个多世纪 ,营养学研究已进入较深层次 ,已证明各种动物均不同程度需要大约 5 0种以上的必需营养素 ,这些营养素的营养功能以及缺乏症已基…     

动物营养与饲料科学研究的焦点问题

营养是动物的客观要求,饲料是营养素供应途径,营养与饲料科学研究的目标是解决畜禽对营养物质＂供＂与＂求＂的矛盾。随着畜禽养殖业和饲料工业迅速发展,动物生产水平和营养物质利用率有了极大提高,本文主要就我国目前的畜牧生产和饲料工业现状谈几点看法。     

我国水产动物营养与饲料的发展概况及展望

一、我国水产动物营养与饲料的发展概况 我国水产动物营养研究始于50年代,但直至80年代才受到国家的重视和关注。近二十年来,在国家、地方水产院校和科研院所的共同努力下,水产动物营养研究取得了相当大的进展。与此同时,水产饲料工业也获得了迅猛发展。 (一)水产动物营养研究进展 从“六五”至今,国家和地方通过立项攻关,已基本摸清了我国主要水产养殖品种的生存、生产和健康所需要的营养元素。迄今为止已证明各种动物均不同程度需要大约50种以上的必需营养素;证明了主要营养素的营养需要量以     

动物营养与饲料科学研究应注意的几个问题

营养是动物的客观要求 ,饲料是营养素供应途径 ,营养与饲料科学研究的目标———解决畜禽对营养物质“供”与“求”的矛盾。随着畜禽养殖业和饲料工业迅速发展 ,动物生产水平和营养物质利用率有了极大提高 ,这 5 0 %～ 75 %取决于营养研究的发展。半个世纪以来 ,动物与营养研究结合 ,使动物生产得到突飞猛进的发展。猪的生长速度和饲料利用率比 5 0年以前提高了 1倍以上。出栏时间缩短到 6个月以下。奶牛产奶量比 5 0年以前提高了6～ 8倍 ,最高达 1 5倍以上 ,每产 1ｋｇ奶只需要 0 .4～ 0 .7ｋｇ日粮 ,其中还包括大约 40 %～ 60 %的粗饲料。…     

饲料工业发展现状与关键技术研究思路浅析（下）

2 动物营养与饲料科学关键技术研究思路 2.1 研究的必要性 营养是动物客观要求，饲料是营养素供应途径，营养与饲料科学研究的目标一解决畜禽对营养物质“供”与“求”的矛盾。     

简论动物生物化学对营养与饲料科学的科研教学启示

动物生物化学是提高动物营养学创新能力的手段,也是动物营养研究的基础。文章从营养物质代谢,营养素与基因互作,营养物质与肉品质调控,营养基因组学,营养遗传组学,营养代谢组学,营养物质与DNA甲基化及组蛋白修饰表观遗传学,mi RNAs与肌肉、脂肪发育的关系,以及Exo-some与营养等方面的生化机制进行论述。旨在分子水平上系统认识营养素既是营养物质,也作为信号分子对基因表达、代谢途径以及性状传递的调控机制,为营养与饲料科学的发展提供有益的科研教学启示。     

狐几种营养代谢性疾病的症状与防治措施

营养代谢性疾病是指饲料中所含的营养物质,特别是维生素和矿物质等供给量不能满足狐体的生长发育需要。有时出现营养代谢性疾病不是因为饲料中营养素的含量不足,而是由于动物的消化机能失调所致。在调配饲料时,还应注意维生素和矿物质间的相互关系。     

当前动物营养学发展的几个方向

动物营养学是一门主要以动物生理学和动物生物化学为基础,揭示营养物质在体内的代谢机理、规律及功能、研究发挥最大遗传潜力对各种营养素的适宜需要量以及评定饲料对动物的营养价值的应用基础科学,它是沟通动物饲养学与动物生理生化等基础学科的桥梁,最终目标是为畜禽饲养中科学配制全价平衡高效饲料,用最少的饲料投入向人类提供量多、质优且安全的畜产品,同时减少畜牧生产对环境的污染,保护生态平衡,     

营养基因组学在动物营养与饲料科学研究中的应用

动物机体的生理和病理变化,如生长发育、新陈代谢、遗传变异、免疫与疾病等,从本质来说都是基因的表达和调控发生改变的结果。营养基因组学是研究营养物质与基因间的相互作用及其对动物生产与机体健康影响的科学。它以分子生物学技术为基础,应用DNA芯片技术、生物标记物和蛋白质组学技术等来阐明营养素与基因表达间的相互关系。主要介绍营养基因组学的概念、研究方法及其在动物营养与饲料科学领域的应用。     

有效降低动物维持需要的措施

动物饲养的维持需要是指动物在维持状态下对 能量和其他营养素的基本需要.营养物质满足维持 需要的生产利用率为零,这种需要仅维持生命活动 的基本代谢过程,弥补营养素周转代谢的损失以及 必要的活动需要.研究动物的维持需要,对于探索 具有普遍意义的营养需要规律,比较不同种类动物 或同一种类动物在不同条件下的营养需要特点具有 重要作用.     

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.