锌对鹅铜锌超氧化物歧化酶和丙二醛含量影响变化的研究

试验选用120只1日龄鹅随机分成四组,A组喂以玉米、大豆为基础饲粮未加锌的饲料,另外3组在基础日粮中添加ZnSO4·H2O,使锌含量分别为40mg/kg(B组),110mg/kg(C组)和2000mg/kg(D组)。分别于15日龄、30日龄和55日龄测定铜锌超氧化物歧化酶(CuZn-SOD)活性和丙二醛含量变化。结果表明,在鹅血清和肝脏中,A、D组CuZn-SOD活性低于B、C组,C组的MDA含量在四组中最低。在整个试验过程中脾脏CuZn-SOD活性和MDA含量没有太大变化。该结果揭示了锌能影响鹅的抗氧化防御系统,锌添加量为110mg/kg时,可提高鹅抗氧化水平。     

锌对鹅淋巴细胞凋亡和细胞增殖周期影响的研究

试验选用120只1日龄鹅随机分成4组，A组喂以玉米大豆为基础日粮未加锌的饲料，另3组在基础日粮中添加ZnSO₄·H₂O，使锌含量分别为40(B组)、110(C组) 和2000 mg/kg(D组)。应用流式细胞仪观测锌对鹅细胞周期和细胞凋亡的影响。结果显示锌添加量为110 mg/kg时，鹅血液淋巴细胞、胸腺、脾脏细胞的增殖指数和DNA含量最高。低锌和高锌饲料可以引起血液淋巴细胞的凋亡。     

高锌对艾维茵肉鸡血液病理学的系统研究

试验将1日龄艾维茵肉鸡健雏200只随机分为4组,分别喂以基础日粮(Zn 100 mg/kg,A组)、高锌日粮Ⅰ(Zn 1 500 mg/kg,B组)、高锌日粮Ⅱ(Zn 2 000 mg/kg,C组)和高锌日粮Ⅲ(Zn 2 500 mg/kg,D组),试验期为7周 .结果表明:B组血清碱性磷酸酶(AKP)活性显著升高(P<0.05),D组显著降低(P<0.05);血清碱性磷酸酶的同工酶亦受到不同程度的影响;谷丙转氨酶(GPT)、淀粉酶(AMY)活性各试验组显著升高(P<0.05);肌酸激酶(CK)活性在试验初期升高,中期不同程度降低(P<0.05),试验结束时与对照组无显著差异(P> 0.05);血清总蛋白(TP)、球蛋白(GLB)含量随锌水平的升高而升高,白蛋白(ALB)含量下降,但均与对照组比较差异不显著(P>0.05);血清锌含量随饲料锌水平增高而显著升高(P<0.05);血清中钙、磷含量则与饲料锌水平呈负相关.     

日粮锌源和添加水平对断奶仔猪组织锌及粪便排泄锌含量的影响

试验选用21日龄"杜×长×大"三元杂交的断奶仔猪40头,按体重和性别随机分成4组(Ⅰ～Ⅳ组),每组10头猪。分别饲喂添加氧化锌(以锌量计)Ⅰ组(对照组)100 mg/kg、Ⅱ组3 000 mg/kg和蛋氨酸锌(以锌量计)Ⅲ组100 mg/kg、Ⅳ组300 mg/kg的基础日粮,预试验7 d,正式试验42 d,结果表明:高锌3 000 mg/kg氧化锌使肝脏、肾脏和十二指肠锌含量极显著升高(P0.01),十二指肠和肝脏锌含量Ⅳ组显著高于Ⅰ、Ⅲ组,脾脏、淋巴结锌含量各组间差异均不显著(P0.05);高锌日粮可使断奶仔猪粪便中锌排泄浓度显著增加,易造成环境污染,日粮添加相同剂量锌的蛋氨酸锌组猪粪便中锌排泄量低于氧化锌组。     

饲粮锌水平对肉鸡血锌、组织锌及含锌酶含量的影响

为研究饲粮中不同锌水平对某些含锌酶活性及血、胰和胫骨锌含量的影响,试验选择1日龄健康AA肉鸡公雏300只,随机分为5个处理组,各处理组锌的含量分别为30、60、90、120、150 mg/kg。结果表明:(1)21日龄时,120、150 mg/kg锌组血锌含量显著增加(P<0.05),与对照组相比,分别提高了56.75%和91.45%;150 mg/kg锌组胰锌含量显著增加(P<0.05),与对照组相比,提高了130.77%;90、120、150 mg/kg锌组胫骨锌含量显著增加(P<0.05),分别比对照组提高14.16%、19.50%和26.61%。42日龄时,150 mg/kg锌组血锌含量显著增加(P<0.05),比对照组提高77.25%;60、90、120 mg/kg锌组胰锌含量显著增加(P<0.05),分别比对照组提高194%、198%和212%;120、150 mg/kg锌组胫骨锌含量显著增加(P<0.05),分别比对照组提高37.80%和43.29%。(2)21日龄时,120、150 mg/kg锌组心肌金属硫蛋白(MT)含量显著增加,分别比对照组提高9.79%和32.17%;90、120、150 mg/kg锌组骨骼肌MT含量显著增加,分别比对照组提高54.55%、57.02%和90.91%。42日龄时,心肌和骨骼肌中的MT含量没有表现出显著的差异。(3)21日龄时,150 mg/kg锌组肝脏铜锌超氧化物歧化酶(CuZn-SOD)活性显著提高,42日龄时,150 mg/kg锌处理组肝脏CuZn-SOD活性显著低于其他处理组。在本试验条件下,饲粮中添加硫酸锌可以显著提高肉鸡血清、胰脏、胫骨组织中的锌沉积,并对肝脏CuZn-SOD活性有一定的影响。     

肉仔鸡饲粮中锌需求参数的研究

取1日龄AA肉仔鸡600只,随机分为10组,每组四个重复,分别喂以含锌40mg/kg的基础日粮和含锌50、70、90和110mg/kg的日粮,研究肉仔鸡对锌的需求参数。试验期8周。结果是6周龄前日粮各水平锌对公、母鸡的体增重和饲料效率无明显差异(P〉0.05),40mg/kg锌可满足其生长需要,但7周龄后,公、母鸡的最大体增重分别在日粮含锌50和90mg/kg。公、母鸡血液中锌含量并无随日粮锌含量的增加而升高,肾脏的锌含量变化也不大,比较敏感的是胰和肝,有随日粮锌含量的增加而升高趋势,公、母鸡分别在日粮含锌90和110mg/kg时胰和肝的含量最高,组织中锌含量依次为胰〉肝〉肾〉血。血液中的碱性磷酸酶活性以日粮含锌70mg/kg的最高,铜锌超氧化歧化酶(CuZnSOD)的活性在不同组织中不同,而且母鸡比公鸡的酶活性高,血液的CuZnSOD在日粮含锌70mg/kg时最高,而肝的CuZnSOD在日粮含锌70mg/kg时最低,以后表现为随日粮锌含量增加而升高,公、母鸡分别在90和110mg/kg时最高。本研究结果认为肉仔鸡对锌的需求参数6周龄前40mg/kg、7周龄后90mg/kg。     

饲粮锌水平对肉鸡生长性能、屠宰性能、血清免疫指标及锌排放的影响

本试验旨在研究饲粮锌水平对肉鸡生长性能、屠宰性能、血清免疫指标及锌排放的影响。选择1日龄健康爱拔益加(AA)肉鸡600只,随机分为5个组,每组6个重复,每个重复20只鸡(公母各占1/2)。各组饲粮锌水平分别为30(基础饲粮组)、60、90、120、150 mg/kg。试验期42 d。结果表明:1)1~42日龄,60、90、120和150 mg/kg锌水平组公鸡的平均日增重显著高于基础饲粮组(P0.05),各组母鸡的平均日增重差异不显著(P0.05)。2)饲粮锌水平对21和42日龄肉鸡免疫器官指数和屠宰性能均无显著影响(P0.05)。3)公鸡21日龄时,120、150 mg/kg锌水平组的新城疫血清抗体滴度显著高于基础饲粮组和60、90 mg/kg锌水平组(P0.05);42日龄时,各组之间新城疫血清抗体滴度差异不显著(P0.05)。母鸡21日龄时,各组之间新城疫血清抗体滴度差异不显著(P0.05);42日龄时,120 mg/kg锌水平组新城疫血清抗体滴度显著高于其他各组(P0.05)。4)饲粮锌水平对21和42日龄肉鸡粪便锌含量和锌表观利用率有显著影响(P0.05)。在不同生长阶段,42日龄的粪便锌含量明显高于21日龄,21日龄的锌表观利用率明显高于42日龄。由此可见,在本试验条件下,饲粮锌水平为60 mg/kg时能满足肉鸡生长的需要,饲粮的锌水平为120 mg/kg时能够保持肉鸡较好的免疫功能。     

甘氨酸铁和甘氨酸锌部分替代无机铁和无机锌对断奶仔猪生长性能及养分消化率的影响

试验旨在研究以甘氨酸铁和甘氨酸锌螯合物部分替代无机铁和锌对断奶仔猪生长性能及日粮营养物质表观消化率的影响。选取204头(25±2)日龄和体质量(7.55±0.31)kg相近的健康三元(杜×长×大)杂交仔白猪,随机分为对照组和试验Ⅰ组、试验Ⅱ组和试验Ⅲ组,每组3个重复,每重复17头,各组间均质量无显著差异(P0.05)。对照组白猪饲喂110 mg/kg硫酸亚铁+110 mg/kg硫酸锌的基础日粮,试验Ⅰ组猪饲喂110 mg/kg硫酸亚铁+55 mg/kg硫酸锌+55 mg/kg甘氨酸锌的基础日粮,试验Ⅱ组白猪饲喂55 mg/kg硫酸亚铁+55 mg/kg甘氨酸铁+110 mg/kg硫酸锌的基础日粮,试验Ⅲ组白猪饲喂55 mg/kg硫酸亚铁+55 mg/kg甘氨酸铁+55 mg/kg硫酸锌+55 mg/kg甘氨酸锌的基础日粮。结果表明:试验Ⅰ组和试验Ⅱ组白猪只的日采食量和末期体质量均显著高于对照组(P0.05),试验Ⅰ组、试验Ⅱ组和试验Ⅲ组料重比较对照组分别降低2.34%、2.34%和5.85%(P0.05);试验组粗蛋白(CP)的消化率显著高于对照组(P0.05),试验Ⅲ组磷(P)的消化率显著高于对照组(P0.05),试验Ⅰ组、试验Ⅱ组和试验Ⅲ组钙(Ca)的消化率显著高于对照组(P0.05)。     

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。     

不同添加剂对鸡蛋品质的影响

选用140d体重相近的宁都三黄母鸡600羽随机分为6组,每组2个重复,每个重复50羽。对照组饲喂基础日粮,Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ组日粮分别在对照组基础上添加(110mg/kg锌+15mg/kg铜)、(0.6mg/kg硒)、(0.5%亚麻酸+1%磷脂+20mg/kg维生素E)、(0.5%中药制剂A)、(0.8%牛蒡),进行为期45d试验。结果表明:试验所用几种添加剂对鸡蛋品质均有不同程度改善作用,其中以锌添加组作用明显,蛋锌含量增高,蛋重、蛋白高度和哈氏单位均提高显著;中药制剂A和牛蒡显著增加鸡蛋蛋白高度与哈氏单位,降低胆固醇;亚麻酸组蛋重增加显著,DHA含量提高;硒添加组蛋硒含量增加,其他蛋品质指标无显著改善。     

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.     

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.     

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.     

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