日粮蛋氨酸水平对肉他鸡的影响

试验选取６００只１日龄ＡＡ肉他鸡，随机分成６组，研究了日粮６个水平的蛋氨酸对其生产性能和血液中甲状腺激素尿酸含量的影响。结果表明：日粮蛋氨酸低于０．２８％或高于１．５％时，肉他鸡生产性能显著下降，血清中尿酸含量显著提高；日粮蛋氨酸０．５％～１．０％时，肉他鸡生产性能与血清中尿酸含量没有显著差异；血浆中甲状腺激素含量不受蛋氨酸水平的影响。     

免疫调节剂对肉仔鸡生产性能和免疫机能的影响

为了解抗生素和免疫调节剂对肉仔鸡生产性能和免疫机能的作用,选用288只21日龄肉仔鸡随机分为6组,分别饲喂对照组(无添加剂)、林可霉素、速大肥、蛋氨酸硒、灵芝孢子粉、蛋氨酸硒 灵芝孢子粉的日粮,试验期21天。试验结果表明：各处理对肉仔鸡3～6周龄的生产性能和免疫器官发育无显著影响;蛋氨酸硒与灵芝孢子粉合用提高了肉仔鸡的屠宰率,降低了腹脂率,但二者不具协同作用;灵芝孢子粉可增加肉仔鸡血清溶菌酶含量,提高血清抗新城疫抗体水平。     

牛黄酸对肉仔鸡卵黄囊吸收及甲状腺激素代谢的影响

以AA肉仔鸡为对象 ,研究了日粮中添加牛磺酸对卵黄囊吸收及甲状腺激素代谢的影响。结果表明 ,肉仔鸡卵黄囊的吸收主要集中在24～72时龄 ,日粮中添加0.10 %的牛磺酸可显著提高此阶段卵黄囊的吸收速度 ,并促进卵黄囊中的胱氨酸、蛋氨酸及赖氨酸的吸收。24～144时龄肉仔鸡血清中甲状腺激素(T3、T4)的水平及肝中T45′-DI活性呈逐渐升高的趋势 ,牛磺酸可显著提高24～120时龄肉仔鸡肝中T45′-DI活性及血清中T3 含量 ,降低血清中T4 含量。     

日粮中不同蛋氨酸水平对感染E.tenella肉仔鸡的影响

试验采用 3× 2试验设计。将 7日龄 36 0只AA肉仔鸡按称重均匀分成 6组 (1、2、3、4、5、6 ) ,每组 6 0只鸡 ,每 5只鸡 1笼 ,饲养在不锈钢笼中。A处理为日粮蛋氨酸添加水平 0、0 .2 %、0 .8% ,B处理为孢子化柔嫩艾美耳球虫 (E .tenella)卵囊 (接种 3× 10 4 个孢子化E .tenella卵囊 ,未接种 )。其中 1、2组饲喂试粮 1(添加 0蛋氨酸 ) ,3、4组饲喂试粮 2 (添加 0 .2 %蛋氨酸 ) ,5、6饲喂试粮 3(添加 0 .8%蛋氨酸 )。 14日龄时 ,1、3、5组的鸡 ,每只分别接种 3× 10 4 个孢子化柔嫩艾美耳球虫卵囊 ,2 2日龄试验结束。结果表明 ,日粮中添加蛋氨酸与未添加蛋氨酸比 ,可以显著提高日增重(P <0 .0 5 )。日粮中添加 0 .8%的蛋氨酸与 0 .2 %相比 ,对试验期间肉仔鸡的生产性能的影响差异不显著 (P >0 .0 5 )。日粮中蛋氨酸水平和柔嫩艾美耳球虫感染对肉仔鸡的免疫器官指数影响不显著 (P >0 .0 5 ) ,但感染组的脾脏指数却都比未感染组大。日粮中蛋氨酸水平可以显著影响感染球虫肉仔鸡抗体的产量 (P <0 .0 5 )。随着日粮蛋氨酸水平的增加 ,血清抗体也随着增加。日粮中蛋氨酸水平可以显著影响感染球虫的肉仔鸡病变记分 (P <0 .0 5 )。日粮中添加 0 .8%的蛋氨酸 ,病变记分显著优于 0 .2 %组、0组 (P <0 .0 5 )。在球     

免疫调节剂对肉仔鸡生产性能和免疫机能的影响

选用288只21日龄肉仔鸡随机分为6组,分别饲喂基础日粮(无添加剂),基础日粮中添加4.4 mg/kg林可霉素、20 mg/kg维吉尼亚霉素、0.3 mg/kg蛋氨酸硒、100 mg/kg灵芝孢子粉、0.3 mg/kg蛋氨酸硒+100 mg/kg灵芝孢子粉的日粮,试验期21 d。试验结果表明:各处理对肉仔鸡21～42周龄的生产性能和免疫器官发育无显著影响;蛋氨酸硒与灵芝孢子粉合用提高了肉仔鸡的屠宰率,降低了腹脂率,但二者不具协同作用;灵芝孢子粉可增加肉仔鸡血清溶菌酶含量,提高血清抗新城疫抗体水平。     

日粮添加发酵银杏叶对1～42 d黄羽肉仔鸡生长性能、血清生化指标和抗氧化性能的影响

试验旨在研究日粮添加不同水平发酵银杏叶对1~42 d黄羽肉仔鸡生长性能、血清生化指标和抗氧化性能的影响。选用960只1 d雌性岭南黄羽肉仔鸡,随机分为4组,每组6个重复,每个重复40羽。对照组饲喂玉米—豆粕型基础日粮,试验1~3组分别饲喂含0.2%、0.4%和0.8%发酵银杏叶日粮,试验期为6周。结果表明:日粮添加发酵银杏叶对22~42 d黄羽肉仔鸡平均日采食量无显著影响(P0.05),添加0.2%发酵银杏叶较其他各组显著提高了黄羽肉仔鸡全期平均日采食量(P0.05);与对照组相比,日粮添加0.4%发酵银杏叶显著提高22~42 d和1~42 d黄羽肉仔鸡平均日增重(P0.05),同时显著降低22~42 d和1~42 d黄羽肉仔鸡料重比(P0.05)。0.4%发酵银杏叶组较对照组显著提高了肉仔鸡血清白蛋白(ALB)含量(P0.05),同时显著降低血清尿酸(UA)和甘油三酯(TG)含量(P0.05)。日粮添加0.4%发酵银杏叶显著提高血清超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-PX)活力(P0.05),显著降低血清丙二醛(MDA)含量(P0.05)。在本试验条件下,综合考虑肉鸡的生产性能和抗氧化性能,玉米—豆粕型日粮中发酵银杏叶的适宜添加水平为0.4%。     

丹参提取剩余物对肉仔鸡生产性能和血清抗氧化指标的影响

试验旨在研究日粮中添加不同水平的丹参提取剩余物对肉仔鸡生产性能和血清抗氧化指标的影响。选用1日龄爱拔益加(AA)肉仔鸡320只,随机分成4个处理,每个处理8个重复,每个重复10只鸡。处理1为对照组,饲喂基础日粮;处理2、3、4为在基础日粮中分别添加0.3%、0.5%和1%丹参提取剩余物的试验组。试验第21、42日龄,空腹称重,统计耗料量,计算生产性能;翅静脉采血,测定血清总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)活性、谷胱甘肽过氧化物酶(GSH-Px)活性和丙二醛(MDA)含量。结果显示,日粮中添加0.3%、0.5%和1%丹参提取剩余物对于肉仔鸡的生产性能没有显著影响(P>0.05)。日粮中添加0.3%丹参提取剩余物对于肉仔鸡血清抗氧化指标的影响差异不显著(P>0.05);日粮中添加0.5%丹参提取剩余物对于肉仔鸡血清总抗氧化能力(T-AOC)影响差异不显著(P>0.05),可以提高超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性,但是差异不显著(P>0.05);日粮中添加1%丹参提取剩余物可以显著提高肉仔鸡血清总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)活性、谷胱甘肽过氧化物酶(GSH-Px)活性(P<0.05),同时可以显著降低血清丙二醛(MDA)含量(P<0.05)。由此可见,在肉仔鸡日粮中添加丹参提取剩余物可以提高肉仔鸡的抗氧化能力,其中添加比例为1%时作用效果最佳。     

不同水平的蛋氨酸对感染球虫(E.tenella)肉仔鸡的影响

试验采用3×2试验设计。将7日龄360只AA肉仔鸡按称重均匀分成6组(Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ),每组60只鸡,每5只鸡一笼,饲养在不锈钢笼中。A处理为日粮蛋氨酸添加水平0%(A1)、0.2%(A2)、0.8%(A3),B处理为孢子化柔嫩艾美耳球虫(E.tenella)卵囊(B1——接种3×104个孢子化柔嫩艾美耳球虫卵囊,B0——未接种)。其中Ⅰ、Ⅱ组饲喂试粮1(A1),Ⅲ、Ⅳ组饲喂试粮2(A2),Ⅴ、Ⅵ饲喂试粮3(A3)。14日龄时,Ⅰ、Ⅲ、Ⅴ组鸡,每只分别接种3×104个孢子化柔嫩艾美耳球虫卵囊,22日龄试验结束。结果表明:①日粮中添加蛋氨酸与未添加蛋氨酸比,可以显著提高日增重(P<0.05),且日粮中添加0.8%的蛋氨酸与0.2%的相比,对试验期间肉仔鸡的生产性能的影响差异不显著(P>0.05);②日粮蛋氨酸水平对肉仔鸡血糖影响不大;③日粮蛋氨酸水平可以显著影响感染球虫的肉仔鸡的病变记分(P<0.05),即日粮中添加0.8%的蛋氨酸,显著优于0.2%组、0%组(P<0.05)。因此,在球虫感染的情况下,高营养水平对其是有效的。     

牛磺酸对肉仔鸡生长性能和免疫功能的影响

以添加不同水平的牛磺酸日粮饲喂艾维茵商品代肉仔鸡,探讨牛磺酸对肉仔鸡生产性能和免疫功能的影响。试验研究表明:日粮中添加牛磺酸可以提高肉仔鸡的生产性能和平均日增质量,降低料肉比,其中以0.1%添加量效果最为显著。各试验组3周龄肉仔鸡免疫效果要好于6周龄,3周龄时,0.1%和0.2%的添加量显著提高脾、法氏囊和胸腺的相对指数,提高血清中总蛋白质量浓度(P<0.05),而对6周龄肉仔鸡免疫器官指数和血清蛋白质量浓度影响差异不显著。     

金霉素与赖氨酸和蛋氨酸交互作用研究

采用3×2×2因子饲养试验和2×2×2因子代谢试验,研究金霉素与赖氨酸和蛋氨酸的交互作用对肉仔鸡生产性能的影响,及金霉素对两种氨基酸代谢的影响。金霉素在饲料中添加150 mg/kg时,对0-3周肉仔鸡具有显著的促生长作用（P<0.01）;并显著提高肉仔鸡的饲料采食量和饲料转化率（P<0.01）,促进氮沉积（P<0.01）。对4-6周肉仔鸡的生产性能无显著影响（P>0.05）;金霉素、赖氨酸和蛋氨酸存在显著的互作关系（P<0.05）。金霉素的促生长效果受饲料中赖氨酸和蛋氨酸含量的影响,当日粮中赖氨酸水平为1.3％,蛋氨酸水平为0.6％时,肉仔鸡的生长性能最高。金霉素对赖氨酸的利用率没有显著影响（P>0.05）,对蛋氨酸和胱氨酸的表观利用率具有显著抑制作用（P<0.05）。研究结果表明持续低剂量金霉素与蛋氨酸和赖氨酸具有交互作用,这种互作关系影响彼此对肉仔鸡生产性能的作用效果,金霉素具有提高肉仔鸡赖氨酸需要量的作用。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

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。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

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.     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

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.     

Prevalence of gastric lesions in racing Alaskan sled dogs

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.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

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.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

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.     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

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.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

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.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

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.     

A brief history of the prevention of infectious diseases by immunisations

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.