高锌对天府肉鹅免疫功能的影响

将1日龄天府肉鹅健雏200只随机分为A、B、C、D共4组，A组作为对照组仅喂基础日粮（Zn 100mg／kg），B、C、D组分别饲喂基础日粮＋Zn900mg／kg、基础日粮＋Zn1400mg／kg和基础日粮＋Zn1900mg／kg，试验期7周，以研究高剂量锌对雏鹅免疫功能的影响。结果，与对照组相比，高锌的B、C和D组雏鹅淋巴器官发育受阻，胸腺、腔上囊和脾的器官生长指数程度不同地降低；胸腺、腔上囊和脾淋巴细胞数量减少、变性、坏死；淋巴细胞分裂增殖受抑，胸腺、腔上囊、脾和外周血淋巴细胞分裂指数程度不同地降低。结果表明，日粮高锌可致雏鹅免疫功能受损。     

铜中毒对雏鸡免疫功能影响的研究

180只1日龄艾维菌肉鸡健雏随机分为3组,分别喂以对照日粮(Cu 11.97 mg/kg)和铜中毒日粮(Cu 650 mg/kg,铜中毒Ⅰ组;Cu 850 mg/kg,铜中毒Ⅱ组)6周,观察铜中毒对免疫功能的影响.与对照组比较,两个铜中毒组雏鸡胸腺、脾脏和法氏囊的生长指数、淋巴细胞生长周期和外周血T淋巴细胞ANAE阳性率显著降低(P＜0.05或P＜0.01);病理组织学观察,淋巴免疫器官淋巴细胞显著减少并呈退性变.结果表明,铜中毒严重抑制淋巴免疫器官生长发育和外周血T淋巴细胞活化,并对淋巴免疫器官造成损伤,导致免疫功能下降.本中还就铜中毒对免疫功能的影响机理进行了讨论.     

雏鸡锌中毒的病理形态学研究

1日龄艾维茵肉鸡健雏200只随机分为四组(Ⅰ-Ⅳ),分别喂以对照日粮(Zn 100mg/kg)、中毒(Zn 1500mg/kg、2000mg／kg、2500mg／kg)日粮7周,进行雏鸡锌中毒的病理学研究。锌中毒雏鸡的生长发育受阻,患病鸡消瘦,精神沉郁,双腿无力,跛行或呈犬坐姿势。尸体剖检见胸腺充血、水肿,腔上囊体积变小,脾脏、心脏、肝脏出现坏死灶,肌胃角质层溃疡。光镜下,免疫器官的淋巴细胞减少,淋巴滤泡形成较少,其皮质变薄、髓质增宽并可见髓质部淋巴细胞减少。结果表明,日粮高锌对雏鸡器官组织可产生明显的毒害作用。     

硫酸粘杆菌素对雏鸡红细胞的影响

通过测定红细胞C3b受体(C3bR)花环率和免疫复合物(IC)花环率,研究了不同添加剂量的硫酸粘杆菌素对雏鸡红细胞免疫功能的影响。试验分为5组,分别为I组(基础日粮对照组)、II组(基础日粮+20mg/kg硫酸粘杆菌素试验组)、III组(基础日粮+40mg/kg硫酸粘杆菌素试验组)、IV组(基础日粮+60mg/kg硫酸粘杆菌素试验组)和V组(基础日粮+80mg/kg硫酸粘杆菌素试验组),结果表明,随日龄和剂量增加,雏鸡红细胞C3b受体花环率和免疫复合物花环率下降,说明不同剂量硫酸粘杆菌素均可不同程度导致雏鸡免疫功能受损,其中80mg/kg添加组最为明显。     

缺锌对雏鸭免疫功能影响的研究

1日龄天府肉鸭 10 0只分为 2组 ,喂以缺锌 (Zn 2 2 9mg)和对照 (Zn 10 0mg)日粮 7周 ,观察缺锌对免疫功能的影响。缺锌组免疫器官的绝对重量、生长指数和淋巴细胞生长周期以及外周血T淋巴细胞ANAE+阳性率、血清免疫球蛋白含量和红细胞C3b受体花环、免疫复合物花环率显著降低 (P <0 0 1或P <0 0 5 ) ;病理组织学观察 ,免疫器官淋巴细胞显著减少并呈退行性变 ,网状细胞变性坏死 ,电镜下淋巴细胞胞核固缩或溶解 ,细胞器消失 ,网状细胞粗面内质网扩张 ,线粒体肿胀 ,出现大小不等的溶酶体、吞噬体和自噬体。结果表明 ,缺锌严重抑制免疫器官生长发育和外周血T淋巴细胞活化 ,显著降低血清免疫球蛋白含量和红细胞免疫功能 ,并对免疫器官造成明显的病理损伤 ,导致免疫功能下降。     

铜中毒对雏鸡红细胞免疫功能的影响

本文旨在研究铜中毒对雏鸡红细胞免疫功能的影响。选用1日龄艾维茵肉鸡健雏180只,随机分为3组,分别喂以对照日粮(含Cu 11.97 mg/kg)和铜中毒日粮(铜中毒I组,含Cu 650 mg/kg;铜中毒II组,含Cu850 mg/kg)6周。结果表明:两个铜中毒组雏鸡的RBC-C3bRR花环率和RBC-ICR花环率降低,红细胞免疫功能受损,肉鸡1~6周龄时与对照组比较差异显著(P<0.05或P<0.01),并与红细胞的形态改变相一致。RBC-C3bRR花环率和RBC-ICR花环率的降低与铜中毒引起的红细胞病理损害密切相关。     

那西肽(Nosiheptide)对肉仔鸡免疫功能的影响

1日龄艾维茵肉仔鸡240只，随机分为4组，每组4个重复，每个重复15只。A0为空白对照组，喂基础日粮；A1喂基础日粮＋1．25mg／kg那西肽（Nosiheptide）；A2喂基础日粮＋2．5mg／kg那西肽；A3喂基础日粮＋5mg／kg那西肽。试验期42d。试验结束后，测定各组胸腺、脾脏和腔上囊系数及外周血和脾脏淋巴细胞的转化率。试验结果表明，那西肽对内仔鸡的免疫器官发育及T、B淋巴细胞转化有押制作用，且押制作用随剂量的增加而增加。     

金银花复方制剂对人工感染NDV雏鸡免疫器官T淋巴细胞及其亚群以及B淋巴细胞的影响

为了研究金银花复方制剂对人工感染NDV雏鸡免疫器官T淋巴细胞及其亚群以及B淋巴细胞的影响,本试验以21日龄雏鸡为研究对象,随机分成感染组、中药治疗组、空白组。中药治疗组饮水给予复方金银花制剂。应用流式细胞仪检测技术,细胞培养技术研究了金银花复方制剂对人工感染NDV雏鸡免疫器官(胸腺、脾脏、腔上囊)T淋巴细胞及其亚群以及B淋巴细胞的影响,旨在揭示金银花复方制剂对人工感染NDV雏鸡免疫器官细胞免疫和体液免疫功能的影响及其机理。研究结果发现,金银花复方制剂能够提高人工感染NDV雏鸡免疫器官胸腺及脾脏CD3~+、CD4~+T淋巴细胞百分率,使CD4~+/CD8~+T淋巴细胞值升高,提高免疫器官脾脏及腔上囊B淋巴细胞百分率,表明金银花复方制剂能够提高雏鸡的免疫功能。     

高铜对雏鸡外周血T-淋巴细胞ANAE阳性率的影响

选用1日龄艾维菌健康肉鸡420只,随机分为7组,分别喂以对照日粮(Cu 11 mg/kg)和高铜日粮(Cu 100mg/kg),高铜Ⅰ组,Cu 200 mg/kg,高铜Ⅱ组;Cu 300 mg/kg,高铜Ⅲ组;Cu 400 mg/kg,高铜Ⅳ组,Cu 500 mg/kg,高铜Ⅴ组;Cu 600 mg/kg,高铜Ⅵ组)6周,观察日粮铜添加水平对雏鸡外周血T-淋巴细胞ANAE阳性率的影响.与对照组比较,高铜Ⅰ、Ⅱ组雏鸡外周血T-淋巴细胞ANAE阳性率增加,但差异不显著;高铜Ⅲ、Ⅳ、Ⅴ、Ⅵ组雏鸡外周血T-淋巴细胞ANAE阳性率降低,且与日粮含铜量呈负相关,同时胸腺淋巴细胞减少,凋亡细胞比例增高.结果表明,与对照组比较,日粮铜含量100～200 mg/kg对雏鸡外周血中T-淋巴细胞ANAE阳性率有促进作用,但差异不显著;日粮铜含量300～600 mg/kg程度不同地降低了T-淋巴细胞ANAE阳性率,细胞免疫功能受损.     

日粮高硒对雏鸡外周血T淋巴细胞增殖功能和亚群的影响

300只1日龄艾维茵肉鸡健雏随机分为5组,分别喂以基础日粮(日粮Se含量0.2 mg·kg-1,对照组)和高硒日粮(Se 1 mg·kg-2,高硒Ⅰ组;Se 5 mg·kg-1,高硒Ⅱ组;Se 10 mg·kg-1,高硒Ⅲ组;Se 15 mg·kg-1,高硒Ⅳ组)6周,用流式细胞术和MTT法研究高硒对外周血T淋巴细胞亚群、淋巴细胞增殖功能的影响.结果显示,当雏鸡日粮硒水平达5 mg·kg-1以上时,外周血CD3+ T细胞、CD3+CD4+T细胞和CD3+CD8+T细胞百分比不同程度地降低;高硒Ⅲ、Ⅳ组的T淋巴细胞增殖能力下降,血清IL-2含量降低,与对照组间差异显著或极显著(P<0.05或P<0.01).结果表明,5 mg·kg-1以上的日粮硒降低雏鸡细胞免疫功能.     

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.     

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

Tropical Animal Health and Production -     

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.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

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