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1.
１日龄父母代罗曼（Ｌｏｈｍａｎｎ）蛋鸡１２０只,随机分为３组,分别喂以低锰（基础日粮含锰１３．６２ｍｇ／ｋｇ）、低锰高磷（基础日粮＋０．５％的磷）、补锰对照（基础日粮＋锰８０ｍｇ／ｋｇ）日粮。试验期８周。饲喂５～８周发病。低锰组发病率２６％,低锰高磷组２８％,补锰对照组无一发病。第４周时,体重分别为（２６７．９±８．３２）、（２１４．２±１０．４２）、（２６５．０±１２．１８）ｇ,低锰组、补锰对照组与低锰高磷组之间差异极显著（Ｐ＜０．０１）。肝锰含量分别为（５．４０±０．７４）、（２．８２±０．３６）、（８．４８±０．９６）ｍｇ／ｋｇ,补锰对照组与低锰组差异显著（Ｐ＜０．０５）,与低锰高磷组差异极显著（Ｐ＜０．０１）。发病症状：精神沉郁,不愿走动,伏卧,跛行,单腿发病病腿向外侧伸展,双腿发病则内收呈“Ｏ”字形或外展呈“八”字形。剖检跗关节肿大,胫骨髁骨骨质增生、肿大,髁间沟变平坦。组织学检查,胫骨骺生长板增殖区变窄,软骨基质中粘多糖减少。超微结构变化,心肌纤维、肝细胞、胫骨骺生长板软骨细胞、睾丸精原细胞等线粒体肿胀与空泡化。  相似文献   

2.
0～4周龄肉仔鸡不同锰源锰需要量的研究   总被引：15，自引：1，他引：14  
试验将３６０只１日龄ＡＡ（ＡｒｂｏｒＡｃｒｅ）肉鸡公雏随机分为添加锰０ｍｇ／ｋｇ,硫酸锰（ＭｎＳＯ４．Ｈ２Ｏ,下同）６０ｍｇ／ｋｇ,１２０ｍｇ／ｋｇ,１５０ｍｇ／ｋｇ和蛋氨酸锰（Ｍｅｔ－Ｍｎ,下同）４０ｍｇ／ｋｇ,６０ｍｇ／ｋｇ,６个组,６个组基础日粮组成及日粮营养水平相同。试验期为４周。结果表明,所有添加锰组体增重均均显著高于不加锰组（Ｐ〈０．０１）,添加锰６０ｍｇ／ｋｇＭｅｔ－Ｍｎ体增重显著高  相似文献   

3.
在高铜（２５０ｍｇ／ｋｇ）日粮中加铁、锌,可显著（Ｐ＜０．０５）或极显著（Ｐ＜０．０１）地增加血红蛋白（Ｈｂ）浓度,血清铁、锌含量和血清碱性磷酸酶（ＳＡＰ）活性,增强红细胞膜（ＲＢＣＭ）稳定性,减少血清铜含量。当日粮中加铁６０ｍｇ／ｋｇ（日粮铁总浓度１５３ｍｇ／ｋｇ）、锌１０５ｍｇ／ｋｇ（日粮锌总浓度１４２ｍｇ／ｋｇ）时,猪血清铁和锌含量、血液Ｈｂ浓度、ＳＡＰ活性、ＲＢＣＭ稳定性达到最大。在高铜日粮中加铁４０～６０ｍｇ／ｋｇ（日粮铁总浓度１３３～１５３ｍｇ／ｋｇ）、加锌７０～１０５ｍｇ／ｋｇ（日粮锌总浓度１０７～１４２ｍｇ／ｋｇ）,能增加猪平均日增重７５．１５％～７６．０７％（Ｐ＜０．０１）,提高饲料转化率６０．１１％～６０．７７％（Ｐ＜０．０１）。结果表明,猪高铜（２５０ｍｇ／ｋｇ）日粮中铁、锌的适宜水平分别为１５３ｍｇ／ｋｇ和１４２ｍｇ／ｋｇ。  相似文献   

4.
不同铜源及水平的日粮对产蛋鸡生产性能及蛋品质的影响   总被引：7，自引：0，他引：7  
用６８周龄海赛克斯蛋鸡,研究玉米－大豆粕－棉仁粕型日粮中添加５水硫酸铜（ＣｕＳＯ４．５Ｈ２Ｏ）形式的铜６ｍｇ／ｋｇ、３０ｍｇ／ｋｇ、６０ｍｇ／ｋｇ、１２５ｍｇ／ｋ和柠檬酸铜（ＣｕＣｉｔ）形式的铜６ｍｇ／ｋｇ、３０ｍｇ／ｋｇ、６０ｍｇ／ｋｇ试验结果表明：与对照组经（含铜６．４ｍｇ／ｋｇ）,日粮中添加６ｍｇ／ｋｇＣｕ（硫酸铜）时耗料最低,蛋壳厚度最大,且随着添加量的增加蛋壳厚度变薄;日粮中添加３０ｍｇ／ｋｇＣｕ（硫酸铜）时产蛋率最高,料蛋比最低,蛋壳强度最大,日粮中添加不同铜源及水平对蛋黄铜含量的影响不大（Ｐ〉０．０５）。与对照组相比,日粮中添加１２５ｍｇ／ｋｇＣｕ（硫酸铜）时肝脏铜水平明显升高（Ｐ〈０．０５）,但各添加组之间的差异不显著（Ｐ〉０．０５）。随着日粮中铜添加水平的提高,蛋黄和肝脏胆固醇水平显著降低（Ｐ  相似文献   

5.
日粮锰水平对蛋鸡生产性能的影响   总被引：8，自引：0，他引：8  
试验用北京红鸡商品代分两阶段２５ ～３８ 周龄和４９ ～５７ 周龄研究玉米－ 豆粕型基础日粮含锰２０ｍｇ／ｋｇ 的情况下,以一水硫酸锰形式添加锰２０ｍｇ／ｋｇ 、４０ｍｇ／ｋｇ、６０ｍｇ／ｋｇ 和蛋氨酸锰２０ｍｇ／ｋｇ 对蛋鸡生产性能及蛋壳、蛋黄锰存留的影响。结果表明：不同锰源及添加水平对蛋鸡生产性能、蛋壳品质、蛋形指数在各组间无显著差异（Ｐ＞ ０ ．０５） ,蛋壳锰含量呈负增长,有机锰组蛋壳锰含量低于无机锰组。蛋黄锰含量却呈现正增长,以蛋氨酸锰组最高,显著高于添加２０ｍｇ／ｋｇ 锰组和不添加组。由此说明锰在蛋壳和蛋黄中存留呈现相反的结果。  相似文献   

6.
不同锰源及锰水平对雏鸭肝脏脂肪沉积的影响   总被引：1，自引：0，他引：1  
选用１日龄北京雏鸭３００只，研究不同锰源及其锰添加水平对雏鸭肝脏脂肪沉积和肝锰含量的影响。试验１随机分为７组，每组３０只试鸭，在基础饲粮中（含Ｍｎ１９ｍｇ／ｋｇ），钙源及锰添加水平依次为４５、８５、１３５ｍｇ／ｋｇ（试剂级ＭｎＳＯ＿４·Ｈ＿２Ｏ或ＭｎＣＯ＿３）。试验２随机分４组，每组３０只试鸭，在基础饲粮上（含Ｍｎ１９ｍｇ／ｋｇ），补锰水平依次为０、１１０、１０００、３５００ｍｇ／ｋｇ（试剂级ＭｎＳＯ＿４·Ｈ＿２Ｏ），试验３周。结果为：锰源不影响雏鸭肝脏脂肪沉积，肝锰含量和千克活体肝重（Ｐ＞０．０５），锰缺乏（含Ｍｎ１９ｍｇ／ｋｇ）或锰过量（补Ｍｎ３５００ｍｇ／ｋｇ）均影响雏鸭肝脏脂肪沉积和肝锰含量变化（Ｐ＜０．０５或Ｐ＜０．０１）。综合试验结果为：如以肝锰变化作为机体锰营养状况评定指标，则饲粮锰适宜添加量为８５～１３５ｍｇ／ｋｇ。  相似文献   

7.
二氢吡啶对蛋品质的影响及其机理研究   总被引：2，自引：0，他引：2  
马玉龙  田斌 《饲料工业》1999,20(11):29-30
取３００ 日龄罗曼蛋鸡１ ５３６ 只，随机分为４ 组（ 每组设４ 个重复，每个重复９６ 只） ，在自由采食、饮水和光照１６ｈ 的条件下，分别饲喂添加０ｍｇ／ｋｇ 、１００ｍｇ／ｋｇ 、１５０ｍｇ／ｋｇ 、２００ｍｇ／ｋｇ二氢吡啶的玉米—豆粕型饲粮１３ 周。结果发现：①饲粮中含１００ｍｇ／ｋｇ 、１５０ｍｇ／ｋｇ 或２００ｍｇ／ｋｇ的二氢吡啶， 能使蛋壳厚度分别增加１１ ．３３ ％ （Ｐ＜ ０ ．０１） 、１６ ．８５％ （Ｐ＜ ０ ．００１） 和２０．１７ ％ （Ｐ＜ ０ ．００１） ；②饲粮中含１５０ｍｇ／ｋｇ 或２００ｍｇ／ｋｇ 的二氢吡啶，能使蛋比重和蛋壳相对重分别增加０ ．４４％ （Ｐ＜ ０ ．０５） 、０ ．５３ ％ （Ｐ＜ ０．０５） 和５ ．６６％ （Ｐ＜ ０ ．０５） 、６ ．９７ ％ （Ｐ＜ ０．０５） ，血清钙含量分别提高了１６．９０ ％ （Ｐ＜ ０ ．０５） 和１８ ．３３％ （Ｐ＜ ０．０５） ，而血清甲状旁腺素水平则分别下降了１８．０４ ％ （Ｐ＜ ０ ．０５） 和２０．００％ （Ｐ＜ ０ ．０５） 。  相似文献   

8.
１１５只３周龄母鸡被分为４组，分别为３９只、３３只、３１只和１２只。四种日粮分别含氯化胆碱（ＣＣＣ）　：０　ｍｇ／ｋｇ（对照）　；５　ｍｇ／ｋｇ从第１４周龄开始（５　ｍｇ／ｋｇ　Ａ）　；５　ｍｇ／ｋｇ从３周龄开始（５　ｍｇ／ｋｇ　Ｂ）　；５０　ｍｇ／ｋｇ从第３周龄开始（５０　ｍｇ／ｋｇ　Ｂ）。基础日粮根据生长期配合，并进行等氮等能处理。第３～８周日粮干物质ＣＰ和ＭＥ分别为１７．９９　％和１２．７　ＭＪ／ｋｇ；第９～２０周ＣＰ和ＭＥ分别为１４．６３　％和１２．７５　ＭＪ／ｋｇ。对鸡采食量、体重变化…  相似文献   

9.
本试验旨在研究饲粮铜添加水平对 １～２８日龄泰和乌骨鸡生产性能和组织黑色素含量的影响。选用 １日龄泰和乌骨鸡 ２７０只,随机分成 ６组,每组设 ３个重复,每个重复 １５只鸡。试验鸡分别饲喂在基础饲粮（铜含量为 ４．７５ｍｇ／ｋｇ）中添加 ０、５、１５、３０、６０、１２５ｍｇ／ｋｇ铜的饲粮,饲养至 ２８日龄。结果表明：饲粮铜不同添加水平对 １～２８日龄泰和乌骨鸡平均日增重、平均日采食量和料重比均无显著影响（Ｐ＞０．０５）,但适量添加可显著或极显著影响其血清、肝脏、肾脏、皮肤及肌肉的黑色素含量、酪氨酸酶活性（Ｐ＜０．０５或 Ｐ＜０．０１）,并呈现出随饲粮铜添加水平的提高先升后降的趋势。当饲粮铜添加水平为 ３０ｍｇ／ｋｇ时,泰和乌骨鸡血清和组织酪氨酸酶活性及黑色素含量达到峰值。由此可知,玉米 －豆粕型基础饲粮中添加铜可提高泰和乌骨鸡组织黑色素含量,其适宜添加水平为 ３０ｍｇ／ｋｇ。  相似文献   

10.
在３×５的两因子试验中,研究了不同添加水平维生素Ｅ（４、１４和２４ｍｇ／ｋｇ）与有机和无机硒（亚硒酸钠０．２０、０．３５和０．５０ｍｇ／ｋｇ,酵母硒０．３５和０．５０ｍｇ／ｋｇ）对褐壳蛋种母鸡在２０～４０周龄阶段生产繁殖性能和有关血液指标的影响。结果表明,产蛋母鸡的采食量、产蛋率、蛋重、产蛋量、饲料转化率和死淘率在３个维生素Ｅ添加水平间无差异;除了添加酵母硒０．５０ｍｇ／ｋｇ组蛋鸡的蛋重和产蛋量显著低于酵母硒０．３５ｍｇ／ｋｇ组以外,其它各项生产性能指标在各硒处理组间差异不明显。维生素Ｅ和硒可增加彼此在血液中的存留;当日粮中只补加维生素Ｅ４ｍｇ／ｋｇ时,将日粮亚硒酸钠硒添加水平由０．２０ｍｇ／ｋｇ提高到０．３５～０．５０ｍｇ／ｋｇ可使血浆α－生育酚含量由０．５０μｇ／ｍｌ上升到接近１．０μｇ／ｍｌ左右。  相似文献   

11.
试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。  相似文献   

12.
Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.  相似文献   

13.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

14.
Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.  相似文献   

15.
Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.  相似文献   

16.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

17.
The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.  相似文献   

18.
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.  相似文献   

19.
The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.  相似文献   

20.
Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.  相似文献   

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