内毒素诱生自由基致兔血循环系统损伤及CA对其影响

将56只健康白兔随机分组:正常对照组( 组)8只,ET处理组( 组)、CA保护组( 组)各24只,第1、2、3、4和5小时分别采集血液制备血浆样品,检测血浆T-AOC、T-SOD活性和MDA含量,第2和第5小时捕杀并迅速采集心脏制备组织匀浆,检测心脏GSH、GSH-ST、GSH-Px活性,研究内毒素(endotoxin,ET)诱导休克兔产生自由基对血浆和心脏的损伤及阳离子A(cationA,CA)对其影响。结果表明: 组各项指标均保持相对稳定; 组MDA含量比 组升高(P<0.01),T-AOC、T-SOD活性比 组降低(P<0.01),而 组的MDA、T-AOC、T-SOD显著高于 组(P<0.05);除心脏GSH-Px活性第5小时降低不明显外, 组GSH、GSH-Px和GSH-ST活性显著降低(P<0.01), 组比 组GSH、GSH-Px、GSH-ST活性高(P<0.01)。结果提示:CA能减轻ET诱生自由基所致的过氧化损伤,有效缓解内毒素引起的血液循环系统毒性损伤。     

试验性脂肪肝出血综合征鸡氧化应激水平和内皮功能变化

将320只14日龄青脚麻鸡随机分为对照组、高脂模型组、雌激素模型组和高脂结合雌激素模型组,每组设4个重复,每个重复20只,共处理28 d.造模14、28 d,测定肝脏氧化应激、血清肝功能和内皮功能相关参数,并进行肝脏病理组织学观察.结果显示,模型组鸡肝脂含量增加、肝细胞脂肪变性,肝脏血管损伤,出现典型的鸡脂肪肝出血综合征(FLHS)病变；与对照组相比,各模型组肝脏MDA含量升高(P＜0.05),SOD和GSH-Px活性降低,血浆AngⅡ含量增加,血清NO含量降低；相关性分析显示,肝脏脂肪变性程度与肝脏MDA含量正相关(P＜0.01),与肝脏SOD和GSH Px活性呈负相关(P＜0.01)；肝脏MDA含量与肝出血分数和血浆AngⅡ含量皆有极显著的相关性(P＜0.01)；肝脏SOD和GSH-Px活性与肝出血分数呈负相关(P＜0.01或P＜0.05),与血清NO含量的变化均呈正相关(P＜0.05)；血浆AngⅡ含量与肝出血分数呈正相关(P＜0.05).结果表明,FLHS发生和发展过程中氧化应激参与了内皮功能紊乱的形成,血管损伤可能与氧化应激和内皮功能失调有关.     

黄芪多糖对银星竹鼠生长、血清生化和抗氧化指标的影响

为探讨黄芪多糖对银星竹鼠生长、血清生化指标和抗氧化指标的影响,试验采用单因素试验设计,将96只银星竹鼠随机分为4组,对照组饲喂基础日粮,试验Ⅰ、Ⅱ、Ⅲ组在基础日粮中分别添加200,400,600 mg/kg的黄芪多糖.预试期7d,正试期60 d,试验结束时,在对照组和生长性能较好的试验Ⅲ组中随机各选取6只竹鼠屠宰取样.结果 表明:与对照组和试验Ⅰ组相比,试验Ⅲ组竹鼠末重、平均日增重(ADG)显著提高,精料料重比(F/G)、粗料F/G、总F/G显著降低(P＜0.05);与对照组相比,试验Ⅱ组精料平均日采食量(ADFI)显著提高(P＜0.05).对比各组各项数据,其中试验Ⅲ组生产性能最好.试验Ⅲ组较对照组竹鼠血清中谷草转氨酶(AST)、总胆固醇(TC)、尿素氮(UN)含量显著降低(P＜0.05),血清中总蛋白(TP)含量显著提高(P＜0.05);试验Ⅲ组与对照组相比,提高竹鼠血清超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和肝脏SOD活性(P＜0.01),降低血清、肝脏丙二醛(MDA)活性(P＜0.01),提高竹鼠血清总抗氧化能力(T-AOC)、谷胱甘肽过氧化物酶(GSH-Px)和肝脏中T-AOC、GSH-Px、CAT活性(P＜0.05).因此,黄芪多糖通过调节竹鼠血清生化指标,促进蛋白质吸收,提高机体抗氧化活性和抗应激能力,从而增强竹鼠的生长性能.     

内毒素致兔红细胞膜ATP酶活性改变及阳离子A的保护作用

为观察内毒素(ET)致兔红细胞膜(ECM)ATP酶(ATPase)活性变化及阳离子A(CA)的保护作用.采用定磷法分别测定正常对照组(Ⅰ组)、内毒素组(Ⅱ组)和阳离子A拮抗组(Ⅲ组)兔ECM的3种ATPase活性.结果除Na+-K+-ATPase、Mg2+-ATPase活性在0.5 h时与Ⅰ组比较无显著差异(P＞0.05)外,Ⅱ组3种ATPase活性在3.0 h内均显著增高(P＜0.01,P＜0.05),而5,7 h全部下降(P＜0.01);与Ⅲ组比较中,Ⅲ组除1 h时Mg2+-ATPase的活性无显著差异(P＞0.05)外,3种ATPase的活性均显著增强(P＜0.05,P＜0.01).结果表明ET可使ECM上3种ATPase活性先增高后降低,而CA对膜ATPase活性有明显保护作用.     

矢车菊素在体外缓解脂肪变性的L02肝细胞的氧化损伤

本试验旨在研究矢车菊素(CY)对发生脂肪变性的L02肝细胞氧化损伤的影响.试验分为4组,各组首先以30mg/mL软脂酸在体外处理24 h使L02肝细胞发生脂肪变性,各组分别添加0、0.01、0.1、1 mg/mL的矢车菊素,连续处理8h后,检测各组细胞内超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性,丙二醛(MDA)含量以及总抗氧化能力(T-AOC).结果表明,在体外CY可以使发生脂肪变性的L02肝细胞内SOD、GSH-Px活性及T-AOC升高,并降低MDA含量.其中,培养体系中添加0.1 mg/mL CY能显著提高细胞内GSH-Px活性和T-AOC(P＜0.05)并降低细胞内MDA含量(P＜0.05);培养体系内添加1 mg/mL CY能够极显著提高细胞内SOD、GSH-Px和T-AOC活性(P＜0.01);并极显著降低细胞内MDA含量(P＜0.01).上述结果可知,在体外CY能有效增强脂肪变形时L02肝细胞的抗氧化能力缓解脂肪变性时的氧化损伤.     

桦木酸对小鼠免疫器官抗氧化能力的影响

本试验旨在研究桦木酸(BA)对小鼠免疫器官抗氧化能力的影响.选取健康的昆明系小鼠28只,随机分为4组(每组7只),每天每只分别按每千克体重0、0.25、0.50、1.00 mg的剂量给予BA,BA混悬于0.2 mL1％可溶性淀粉溶液中.以灌胃方式给予,每天灌胃1次,连续灌胃14 d后,检测各组小鼠脾脏和胸腺中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GHS-Px)活性,丙二醛(MDA)含量以及总抗氧化能力(T-AOC).结果表明:BA可使小鼠脾脏和胸腺中SOD、GSH-Px活性以及T-AOC升高,MDA含量降低.其中,每千克体重灌胃0.50 mg BA能显著或极显著提高脾脏和胸腺中GSH-Px活性和T-AOC(P＜0.05或P＜0.01),显著或极显著降低胸腺和脾脏中MDA含量(P＜0.05或P＜0.01);每千克体重灌胃1.00 mg BA能显著或极显著提高脾脏和胸腺中SOD活性、T-AOC以及脾脏中GSH-Px活性(P＜0.05或P＜0.01),极显著降低胸腺和脾脏中MDA含量(P＜0.01).由此得出,BA能有效地增强小鼠免疫器官的抗氧化能力.     

酵母硒、黄芪多糖及其复合剂对半番鸭生长性能、肉品质和抗氧化能力的影响

本文旨在研究酵母硒、黄芪多糖及其复合剂对半番鸭生长性能、肉品质和抗氧化能力的影响。从同一批饲养的22日龄半番鸭中挑选出体重相近的144只,随机分为4组,每组3个重复,每个重复12只鸭,试验期为49 d。采用2×2因子水平设计,对照组饲喂基础饲粮,试验Ⅰ组饲喂基础饲粮+0.3%酵母硒,试验Ⅱ组饲喂基础饲粮+300 mg/kg黄芪多糖,试验Ⅲ组饲喂基础饲粮+复合剂(300 mg/kg黄芪多糖+0.3%酵母硒)。试验期间测定生长性能指标,并于70日龄每组随机选择12只(每重复4只)进行屠宰,测定其胸肌肉品质和抗氧化指标。结果显示:1)试验Ⅰ组和试验Ⅱ组平均日增重、平均日采食量及料重比与对照组相比差异均不显著(P0.05);试验Ⅲ组平均日增重显著高于对照组(P0.05),平均日采食量和料重比与对照组无显著差异(P0.05)。2)与对照组相比,试验Ⅰ组、试验Ⅱ组和试验Ⅲ组24 h p H均显著或极显著提高(P0.05或P0.01),48 h滴水损失率、蒸煮损失率、剪切力显著或极显著降低(P0.05或P0.01);试验Ⅲ组肉色红度(a*)值显著提高(P0.05);试验Ⅱ组和试验Ⅲ组肉色黄度(b*)值均显著降低(P0.05)。3)试验Ⅰ组、试验Ⅱ组和试验Ⅲ组24~120 h的超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性及总抗氧化能力(T-AOC)均显著或极显著高于对照组(P0.05或P0.01);试验Ⅰ组、试验Ⅱ组48~120 h和72~120 h的丙二醛(M DA)含量分别显著或极显著低于对照组(P0.05或P0.01),试验Ⅲ组24~120 h的MDA含量极显著低于对照组(P0.01)。随储存时间延长,各组SOD、GSH-Px活性和T-AOC均呈下降趋势,MDA含量则呈上升趋势,但3个试验组各抗氧化指标的变化速度比对照组缓慢。4)酵母硒和黄芪多糖对肌肉24 h p H、剪切力、24~120 h的SOD活性、48~120 h的GSH-Px活性、120 h的M DA含量有显著或极显著交互作用(P0.05或P0.01)。由此可见,酵母硒、黄芪多糖均可改善半番鸭肌肉品质和提高抗氧化能力,降低脂质过氧化程度,有效延长货架期,且二者对于肌肉抗氧化、p H和嫩度改善均具有明显的协同效应。     

牛磺酸对后备蛋鸭机体抗氧化功能的影响

本试验旨在研究玉米一豆粕型无鱼粉日粮中不同牛磺酸的添加量对笼养后备蛋鸭机体抗氧化功能的影响.试验采用单因素完全随机分组设计,选择12周龄、健康、体重相近的金定蛋鸭180只,随机分为5组,每组6个重复,每个重复6只.Ⅰ组为对照组,饲喂玉米一豆粕无鱼粉日粮,Ⅱ、Ⅲ、Ⅳ、Ⅴ组在基础日粮的基础上分别添加0.05％、0.10％、0.15％和0.20％的牛磺酸,试验期为6周.结果表明,与对照组相比,在日粮中添加0.15％牛磺酸可以显著提高血清还原型谷胱甘肽酶(GSH-Px)、超氧化物歧化酶(SOD)、总抗氧化能力(T-AOC)和过氧化氢酶(CAT)活性(P＜0.05),并且显著降低了丙二醛(MDA)含量(P＜0.05);在日粮中添加0.10％和0.15％牛磺酸可以显著提高肝脏GSH-Px、SOD、T-AOC和CAT活性(P＜0.05),并且显著降低MDA含量(P＜0.05).结果提示,在笼养后备蛋鸭日粮中添加0.10％的牛磺酸,可显著提高机体抗氧化性能,并且经济效益最佳.     

槲皮素对镉致大鼠肝脏损伤的研究

为了研究镉致大鼠肝脏损伤及槲皮素对损伤的作用,试验以SD大鼠为研究对象,将20只大鼠随机分为4组,即空白对照组、镉处理组、槲皮素组和镉+槲皮素组。6周后,采集血清并处死大鼠,取肝脏组织并制成匀浆液,检测血清中天冬氨酸转氨酶(AST)和丙氨酸转氨酶(ALT)活性,肝脏中丙二醛(MDA)、还原型谷胱甘肽(GSH)含量及过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSHPx)、超氧化物歧化酶(SOD)活性。结果表明:与空白对照组比较,镉处理组AST、ALT活性极显著升高(P0.01),MDA含量显著升高(P0.05),GSH含量极显著降低(P0.01),GSH-Px、CAT、SOD活性显著或极显著降低(P0.05或P0.01);与镉处理组比较,镉+槲皮素组AST、ALT活性显著或极显著降低(P0.05或P0.01),MDA和GSH含量分别显著降低和升高(P0.05),GSH-Px、CAT、SOD活性显著或极显著升高(P0.05或P0.01)。说明槲皮素能保护由镉导致的肝脏损伤。     

地克珠利对球虫感染雏鸡血清抗氧化功能的影响

选择120只14日龄雏鸡,随机分为对照组(Ⅰ)、感染组(Ⅱ)和地克珠利组(Ⅲ),每组40只.除Ⅰ组外,其余每只鸡口服感染8.0x104个E.tenella孢子化卵囊,分别于感染后第0、3、6、9、12天,每组随机取鸡5只,心脏采血,对血清超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)活性和丙二醛(MDA)含量进行测定.结果表明,与Ⅰ组比较,Ⅱ组血清SOD活性在感染后3、6、9 d极显著降低(P《0.01),GSH-Px活性在感染后6 d下降显著(p《0.05),MDA含量和CAT活性均表现不同程度的升降,但差异不显著(p》0.05).在感染高峰期(6 d),Ⅲ组血清SOD、GSH-Px、CAT活性虽然与Ⅱ组的差异未达显著水平,但分别较其提高了7.33%、19.82%和52.08%,MDA含量降低了14.58%,且GSH-Px、CAT活性与MDA含量与Ⅰ组比较差异不显著.提示地克珠利在一定程度上能增强球虫感染鸡的抗氧化能力.     

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.     

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     

Evaluation of the Microbiological Status of Milk and Various Structures in Mammary Glands from Naturally Infected Dairy Cows

A knowledge of the microbiological status of milk and of the different structures in the mammary glands has great importance in elucidating the pathogenesis of mammary gland infections. The objective of this study was to evaluate the microbiological status of various structures in the mammary glands from naturally infected dairy cows following slaughter. A total of 94 samples of milk, 184 samples of mammary parenchyma, 168 samples of gland cisterns, and 168 samples of teat cisterns were collected for microbiological examination. Microorganisms were detected in 59.9% of all samples, 67.0% of the milk samples, 70.1% of the mammary parenchymas, 55.9% of the gland cisterns and 48.8% of the teat cistern samples. When all samples were considered, coagulase-negative Staphylococcus were the most prevalent (35.7%) followed by coagulase-positive Staphylococcus (12.2%), Corynebacterium bovis (2.4%), Prototheca sp. (1.9%), and Streptococcus dysgalactiae (1.5%). There was a significantly higher occurrence of microorganisms in the milk and mammary parenchyma compared to the gland cisterns and teat cisterns. This revised version was published online in July 2006 with corrections to the Cover Date.     

Development and survival of free-living stages of gastrointestinal nematodes of sheep and goats on pasture in the Nigerian derived savanna

Four grass plots were sequentially contaminated with goat faeces containing known numbers of unembryonated eggs of predominantly Haemonchus contortus and Trichostrongylus spp. between October 1982 and April 1983. Four other plots were similarly contaminated with sheep faeces between February and May 1987. An additional plot was repeatedly contaminated with sheep faeces from February to April 1987. Populations of free-living stages in faeces and of infective larvae (L₃) in the herbage were subsequently monitored until the end of April and June of 1983 and 1987 respectively. During February and May 1987 two control cultures of sheep faeces were incubated in the laboratory at 25°C–30°C and at a constant temperature of 50°C and the free-living development was also monitored. L₃ developed very readily in the faeces cultured at 25°C–30°C and in those spread on a grass plot in October, at the end of the wet season, but developed less on the plot contaminated in May at the start of the wet season. Worm eggs in faeces deposited on plots during the hot dry season (December to April) or incubated at 50°C died and disintegrated after 24–48 h exposure to the high environmental temperatures. The results indicate that it is unlikely that gastrointestinal nematodes of sheep and goats can develop or survive on open pasture during the dry season in the Nigerian derived savanna zone.