从实验感染鸡血液中最大量提取巴氏杆菌试验

通过对AA鸡不同途径攻毒及不同时间不同途径的采血试验,结果表明:通过翅静脉攻毒,在鸡濒死挣扎时的即刻颈静脉无菌放血,再通过差速和蔗糖密度梯度离心,可以从攻毒鸡的血液中提取到最大量的体内培养的巴氏杆菌。用这样的方法,每只鸡可提取到约300～400亿菌,比以前用的方法提高1000倍以上。提取的细菌灭活后免疫鸡,经异型菌交叉攻毒试验,结果表明体内繁殖的巴氏杆菌具有交叉保护特性。     

禽多杀巴氏杆菌的交叉保护性研究

经差速和蔗糖密度梯度离心，从Ｐ１０５９感染鸡的血液中提取巴氏杆菌。每羽鸡可提取较纯的菌液约１０ｍｌ，含菌量在１００亿／ｍｌ以上。该菌液灭活后免疫鸡，用异型菌Ｃ４８１交叉攻毒，结果与肝组织苗免疫的一样，均具有５０％的保护率，而Ｐ１０５９攻毒耐过鸡则全保护。结果证明，体内繁殖的巴氏杆菌具有交叉保护性，而体外培养菌则没有。     

禽巴氏杆菌病B_（26）－T_（1200）弱毒疫苗的田间免疫试验

用５批禽巴氏杆菌Ｂ２６－Ｔ１２００弱毒疫苗共接种３００万只鸡．现场观察６２４３７只免疫鸡．结果表明，该菌对不同品种鸡安全．只有３．８％免鸡表现为一过性食欲减少、精神稍差．但２天内都能恢复正常，没有引起免疫鸡直接死亡现象．田间免疫１４０天抽取各批苗免疫鸡攻毒，有８０％（１６／２０）鸡得到保护，免疫鸡群在免疫１４０天内没有发生禽巴氏杯菌病．     

AE灭活疫苗ELISA抗体与攻毒保护效果试验

用禽脑脊髓炎灭活疫苗免疫28日龄SPF鸡10只,5只对照不免疫,免疫后21d采血分离血清,ELISA抗体效价检测,采血后马上进行攻毒,攻毒后观察统计发病情况,在试验鸡出现典型症状及攻毒后21d试验结束日,存活鸡全部采血测抗体,对比抗体与攻毒保护效果之间的关系。结果表明:攻毒前免疫鸡ELISA抗体阳性率为80%,攻毒保护效果80%,对ELISA抗体阳性鸡攻毒均有保护。     

禽多杀性巴氏杆菌菌影活体免疫效果评价

本试验旨在评价化学法制备禽多杀性巴氏杆菌菌影疫苗的活体免疫效果。80只12周龄健康的海兰灰母鸡被随机分为4组:A组(未免疫)、B组(口服免疫)、C组(皮下注射免疫)和D组(静脉注射免疫)。结果显示,相比于未免疫组(A组),菌影免疫组(B、C组和D组)显著提高了蛋鸡IgG抗体水平、CD4~+和CD8~+百分比和血清抗菌力,并且显著降低攻毒后蛋鸡脏器中的病原菌负载量和死亡率(P0.05)。表明鸡只免疫化学法制备禽多杀性巴氏杆菌菌影疫苗能够增强体液免疫和细胞免疫水平,从而保护鸡只免受多杀性巴氏杆菌感染。     

禽巴氏杆菌病B_(26)-T_(1200)弱毒疫苗对鸡的安全范围和免疫剂量的测定

以20%铝胶生理盐水稀释的禽巴氏杆菌病 B_(26)-T_(1200)弱毒疫苗,按不同剂量皮下接种鸡,两周后攻毒。结果,41万组1/5鸡获得保护:83万组2/5鸡存活;130万～3000万9个组的保护数稳定在4/5～5/5之间,对大剂量活菌接种鸡,观察15天,结果,26亿～93亿共8个组,均2/2健活,无异常;100亿,109亿和150亿组1/2鸡健活,1/2鸡死亡;171亿组鸡2/2死亡.     

禽巴氏杆菌病B26—T1200弱毒疫苗的田间免疫试验

用５批禽巴氏杆菌Ｂ２６－Ｔ１２００弱毒疫苗共接种３００万只鸡。现场观察６２４３７只免疫鸡。结果表明，该苗对不同品种鸡安全，只有３．８％免鸡表现为一过性食欲减少，精神稍差，但２天内都能恢复正常，没有引起免疫鸡直接死亡现象。田间免疫１４０天抽取各批苗免疫鸡攻毒，有８０％（１６／２０）鸡得到保护，免疫鸡群在免疫１４０天内没有发生禽巴氏杆菌病。     

一例猪巴氏杆菌病的诊断及体外抑菌试验

为了确诊某猪场患病猪的病原菌,找到防控办法,对死亡猪肺脏、气管液进行细菌分离鉴定,经过生化试验、药敏试验、体外抑菌试验、动物试验等,得知:分离菌培养特性、生化反应特性与巴氏杆菌基本一致;分离菌高敏药物为头孢氨苄、头孢曲松等,低敏药物为青霉素G、林可霉素等;乳酸菌对巴氏杆菌有明显的抑菌作用;攻毒小白鼠48 h内全部死亡。结论:分离菌为多杀性巴氏杆菌,该病为多杀性巴氏杆菌引起的猪巴氏杆菌病,乳酸菌配合高敏药物能防治该病。     

鸡霍乱口服弱毒菌株的选育及其性能的研究IR1－23菌株的筛选

试验以本所历年来分离、收集、保存的多株禽源多杀性巴氏杆菌菌种为选种素材，以各菌株的培养特性、菌落形态、菌落虹彩、生化反应及其在历次传代过程中的稳定性为选种依据，初步筛选出四个菌株，代号为：ＲＩ—２３、ＲＩ—２４、ＲＩ—３９和ＲＩ—６５、经过皮下注射安全量、口服耐受量、近期免疫效力和毒力稳定性比较测试后，筛选出一株既适应鸡口服免疫又具有良好免疫原性的自然弱毒菌株──Ｒ１－２３菌株（５：Ａ）。该菌株的皮下注射安全量为每只５０亿个活菌，一次性口服的耐受量每只在２０００亿个活菌以上，活体继代６代次、人工培养继代５０代次后均未见有毒力增强表现，两次口服免疫后的近期保护率达８０—１００％。     

禽霍乱G190E40弱毒菌株的试验研究（一）免疫剂量与攻强毒剂量的关系和大剂量毒力测定试验研究

给鸡肌肉内注射２０００和１０００万Ｇ１９０Ｅ４０活菌苗，１４ｄ后，攻同样剂量强毒，经前后４次试验证明，均能产生坚强免疫力。注射２０００万活菌苗攻不同剂量强毒，其免疫效力保护有所不同，攻５个强毒菌保护５／５、攻２５、３０个强毒菌均保护４／５、攻１０、１５、２０个强毒菌各保护２／５、３／５、３／５。肌肉或皮下注射Ｇ１９０Ｅ４０活菌苗６０亿和７２亿试验鸡全健活     

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.     

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.     

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.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -