日粮中添加非蛋白氮对杂交绵羊生长性能、血液指标的影响

通过研究非蛋白氮（NPN,新型包被尿素）添加剂对绵羊的生长性能及血清生化指标的影响,为该新型包被尿素添加剂在绵羊日粮中的安全性、适宜用量以及饲喂效果提供科学依据。     

日粮中添加非蛋白气氮对杂交绵羊生长性能、血液指标的影响

通过研究非蛋白氮(NPN,新型包被尿素)添加剂对绵羊的生长性能及血清生化指标的影响,为该新型包被尿素添加剂在绵羊日粮中的安全性、适宜用量以及饲喂效果提供科学依据.     

不同氮源对绵羊生长、氮代谢的影响

研究了不同氮源(尿素、包被尿素、包被尿素+0.2%益生素)对杂交绵羊(萨福克×小尾寒羊)生长性能、氮代谢的影响.结果表明不同氮源日粮对绵羊的生长性能影响差异不显著(P＞0.05),但包被尿素组和包被尿素+0.2%益生素组的总增重和日增重要高于其他各组;添加包被尿素+益生素的日粮能提高杂交绵羊的氮沉积和可消化氮,增加了沉积氮与进食氮以及沉积氮与可消化氮的比例,减少了杂交绵羊的尿氮及粪氮排出.     

非蛋白氮日粮中添加益生素对绵羊生长性能和血液指标的影响

选用40只5月龄的杂交绵羊(萨福克×小尾寒羊),随机分为2组,包被尿素组饲喂A日粮(2%包被尿素)、组合组饲喂B日粮(2%包被尿素+0.2%益生素)。研究益生素对杂交绵羊的生长性能、血清中的碱性磷酸酶(AKP)、谷氨酸转氨酶(ALT)、天门冬氨酸转氨酶(AST)、尿素氮(BUN)等指标的影响。结果表明:①添加益生素对绵羊的总增重和日增重差异不显著,但组合组的总增重和平均日增重要高于包被尿素组;②添加益生素对绵羊的碱性磷酸酶值影响差异不显著(P>0.05),但组合组碱性磷酸酶高峰值要低于包被尿素组;③饲喂后2h即10:30,血清中的天门冬氨酸转氨酶活性包被尿素组显著高于组合组(P<0.05),饲喂6h以后各个组别逐渐接近并趋于正常值;④饲喂后3h,组合组的丙氨酸转氨酶值显著低于包被尿素组(P<0.05),饲喂7h以后,各组血清中的丙氨酸转氨酶活性差异不显著;⑤饲喂后各组之间尿素氮差异不显著(P>0.05),但组合组血液中的尿素氮达到高峰的时间要长于包被尿素组。     

日粮中不同氮源对杂交绵羊消化代谢的影响

选用9只5月龄的萨福克×小尾寒羊杂交绵羊,随机分为3组,研究日粮中不同来源氮对绵羊消化代谢的影响.对照组饲喂常规日粮A,试验组分为2组,分别为尿素组饲喂日粮B(2%尿素)和包被尿素组饲喂日粮C(2%包被尿素).结果表明,与日粮B相比,日粮C使绵羊沉积氮与进食氮、沉积氮与可消化氮的比列显著提高,显著减少绵羊粪氮的排出.和其他日粮相比,日粮C提高了绵羊的沉积氮,但差异不显著.各组进食干物质、进食氮、尿氮及可消化氮间差异不显著:日粮C可显著提高绵羊中性洗涤纤维(NDF)的消化率,干物质消化率、氮表观消化率、酸性洗涤纤维(ADF)和酸不溶灰分(AlA)的利用率差异不显著.结果表明,绵羊日粮中添加2%尿素和2%包被尿素安全可靠,效果明显,其中日粮C对氮利用率效果最好.     

缓释尿素对绵羊瘤胃液理化指标的影响

选用 5只 10月龄装有永久性瘤胃瘘管的绵羊 ,按 5× 5拉丁方试验设计 ,研究了 5种不同处理的日粮对绵羊瘤胃消化代谢的影响。通过对瘤胃液pH值、氨态氮、尿素氮浓度的测定结果表明 ,以尿素部分替代混合日粮中的豆粕作为蛋白源 ,瘤胃液pH值、氨态氮等生理指标均处于正常范围。经包被处理的缓释尿素 ,食后 0 .5h时瘤胃中氨态氮的释放速度低于直接添加尿素组 ;以聚乙烯醇 (PVA)包被的尿素 ,食后 0 .5h时瘤胃液尿素氮浓度高于其它处理组。从而初步证明尿素经包被处理可在某种程度上减缓释氨速度     

尿素缓释技术及应用

尿素是一种非蛋白氮饲料添加剂，对反刍动物的生长起积极作用。但是尿素易中毒，尿素缓释技术包括调制日粮的组成，使用脲酶抑制剂，包被尿素，糊化淀粉尿素和尿素复合舔砖的方法等，以及应用前景。     

谨防绵羊的尿素中毒

正尿素作为非蛋白质性饲料添加剂在动物的饲养中得到了部分应用,但它是双刃剑,应用得当会起到意想不到的效果,应用不当就会引起中毒,抢救不及时还能引起动物的死亡,因为绵羊对尿素敏感,在应用尿素时一定要谨慎,防止尿素中毒。1尿素中毒的主要临床症状2017年10月10日,我地区的一个绵羊饲养户,饲养了80只绵羊,听说尿素可提高绵羊的生长速度,就在饲料中添加了尿素,平均每只羊每天1000g,喂后羊先后出现神经症     

饲用缓释包被尿素的质量评价

饲用缓释包被尿素相比于普通尿素，能减缓尿素释放速率、提高氮利用率、更好的促进微生物蛋白的合成。目前，市场上缓释包被尿素产品种类较多，为评价缓释包被尿素饲料的产品质量，本文从颜色气味、粒度、包被材料、平均抗压碎力进行表型测定，从水分含量、尿素含量、氮含量进行理化成分的检测，选择1 h尿素释放率评估尿素缓释效果，旨在建立一套缓释包被尿素饲料评价体系，用于对饲用缓释包被尿素产品质量的评估。     

含尿素颗粒饲料、舔砖和添加剂对绵羊短期育肥效果的评述

前言青海草地畜牧业正处在由粗放经营向集约化经营转变的时期。强化绵羊育肥技术措施 ,优化羊群结构 ,提高出栏率 ,加快羊群周转 ,是这一时期着力研究的重要课题。为了达到绵羊强度育肥的效果 ,降低饲料成本 ,我们根据“高效牧业综合技术开发研究”项目中饲料开发及牛羊育肥技术的研究内容 ,自行研制了两种含尿素的精料补充料—尿素颗粒料、营养舔砖和一种含尿素营养添加剂 ,并于 1998— 2 0 0 0年在青海省贵南县森多乡对藏系绵羊进行了多次短期育肥试验 ,取得了显著的增重效果和经济效益。2　材料与方法2 1　尿素颗粒饲料组成及育肥试验…     

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 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 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 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.

     

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.