涂林吉（苏云金）芽胞杆菌伴胞晶体毒素对捻转血矛线虫虫卵的致死作用

从感染捻转血矛线虫山羊的直肠内取粪便，分离出虫卵，置单克隆板孔中，再往各孔中加入系列浓度的涂林吉（苏云金）芽胞杆菌（ＹＢＴ－１９５３）伴胞晶体毒素溶液，置２５℃培养２４ｈ。结果表明，当伴胞晶体毒素总蛋白为１２０μｇ／ｍＬ时，虫卵死亡率为９９．４％，０．６％未死的虫卵孵出的第１期幼虫也因毒素的作用而全部死亡。本研究表明，涂林吉芽胞杆菌（ＹＢＴ－１９５３）伴胞晶体蛋白对捻转血矛线虫虫卵具有较强的毒力。     

苏云金芽胞杆菌晶体毒素对体外培养的日本血吸虫童虫的作用

将感染日本血吸虫的钉螺常规逸蚴，经注射器推压机械断尾获得的童虫，加入内含１０％兔血清的ＲＰＭＩ－１６４０培养液后，置于单克隆培养板内，以苏云金芽胞杆菌（菌株ＹＢＴ－１９５５）制得的伴胞晶体毒素，以不同的浓度加入以上各孔中于３７℃，５％ＣＯ２培养箱内培养。培养１２ｈ后发现童虫活动力减弱，有些已经死亡；２４ｈ后，随着加入伴胞晶体毒素浓度的增加，童虫死亡率也相应增加，呈正相关（ｒ＝０．８９７）。经毒素蛋白含量为４０ｍｇ／Ｌ处理的童虫，２４ｈ后死亡率为１００％，ＬＤ５０为１５．９５μｇ（１ｍＬ）。     

初乳对新生仔猪血液蛋白的电泳形态影响的研究

２４头太湖猪新生仔猪（二花×大白）分为四组，在出生后隔离并分别人工哺喂葡萄糖盐水（ＧＳ组，ｎ＝４），牛初乳（ＢＣ组，ｎ＝５），牛乳（ＢＭ组，ｎ＝６）４８ｈ和自然哺乳（ＰＣ组，ｎ＝９）。前３组在４８ｈ后回圈哺乳。初乳对新生仔猪血液蛋白电泳形态的影响，新生仔猪血清蛋白质浓度初生时平均为３１．８±１．８６ｍｇ／ｍｌ，ＰＣ组在出生后迅速增加，２４ｈ达８１．７８±８．６ｍｇ／ｍｌ此后略有下降。４８ｈ为５６．６７±１１．３６ｍｇ／ｍｌ，第７天为８７．６７±３．８９ｍｇ／ｍｌ。ＢＣ和ＢＭ组与ＰＣ组有相似的变化；而ＧＳ组在４８ｈ内一直下降，４８ｈ为６．２５±２．２８ｍｇ／ｍｌ，自然哺乳后，第７天上升为４７．７５±２．６８ｍｇ／ｍｌ。但ＢＭ、ＧＳ组在２４ｈ、４８ｈ和第７天血清总蛋白浓度显著低于ＰＣ组（Ｐ＜０．０１）。血清ＳＤＳ—ＰＡＧＥ电泳显示，清蛋白（ＳＡ）ＰＣ、ＢＣ、ＢＭ三组４８ｈ内持续增加，ＧＳ组２４ｈ后显著下降，并且ＧＳ组在高分子量区（１５０ｋｄ）出现非抗体蛋白和多肽的聚合，其他三组则未见到。实验中未观察到牛乳酪蛋白向仔猪血液中的转移。     

牛体外受精胚胎一步脱防冻剂冷冻方法的研究

为了研究适合于牛体外受精胚胎的一步除防冻剂的冷冻方法，特进行两个试验。试验１分别用１．５Ｍ甘油＋０．２５Ｍ蔗糖、１．５Ｍ乙二醇和１．５Ｍ丙二醇作防冻剂冷冻体外受精后第７天，已发育至囊胚阶段的牛胚胎。使胚胎降温至－７℃后，植冰，然后以０．３℃／分的速率降温至－３０℃，立即将胚胎投入液氮中冷冻保存。在３７℃水中解冻胚胎后，使其直接在含１５％胎犊血清（ＦＣＳ）的磷酸缓冲液（ＰＢＳ）中脱去防冻剂。经体外培养７２ｈ后，３组胚胎的孵化率分别为７７．２７％（１０２／１３２）、７３．２４％（１０４／１４２）、４７．９０％（５７／１１９），第１、２组的孵化率极显著高于第３组（Ｐ＜０．０１），说明用１．５Ｍ丙二醇溶液冷冻的胚胎，在解冻后不宜直接在ＰＢＳ中脱防冻剂。试验２比较用不同浓度（１．０Ｍ０１．５Ｍ，２．０Ｍ）的乙二醇和不同投液氮温度（－２５℃，－３０℃，－３５℃）冷冻胚胎的效果。结果表明乙二醇浓度和投液氮温度对胚胎孵化率均无显著影响（Ｐ＞０．０５），各组胚胎的孵化率变动于７４．４４％－８５．４８％之间。     

添食蜕皮素和20—羟蜕皮素对家蚕幼虫发育的不同影响

试验结果表明：液体培养基以７％米粉的本方最好。液发酵的时间为一级培养４０ｈ，二级培养２６．５ｈ。固体培养的栽体以谷壳加麦麸经消毒的接菌为好。固体培养的室温在１６－２２℃为最适宜。相对湿度以第１天为９５％以上，第２－３天以１００％，即达到饱和水为好。菌粉干燥的温度在３０－３８℃，时间在２４－４８ｈ为宜。     

羔山羊卵巢卵母细胞体外成熟培养条件的研究

将出生后５０～７０日龄的羔山羊，经超数排卵处理以后，从卵泡中抽取卵母细胞，取外观形态正常的卵母细胞分成五组，在含有１０％胎牛血清（ＦＣＳ）的ＴＣＭ－１９９培养液中分别经１２、１６、１８、２０和２４ｈ的体外成熟培养后进行体外受精，探索不同体外成熟培养时间对体外受精及卵裂率的影响。另外，在成熟用培养基内还分别添加了发情母羊血清（ＥＮＧＳ）和ＦＣＳ以观察其培养效果。结果表明，经过１２～２４ｈ体外成熟培养的卵母细胞，在体外受精后的４８ｈ检查卵裂率分别为１０％、３７．１％、５０．０％，４１．２％和２５．０％，卵母细胞经体外成熟培养１６～２０ｈ的卵裂率显著高于１２ｈ和２４ｈ的卵裂率。在成熟培养基内分别添加ＥＮＧＳ和ＦＣＳ，其体外受精卵的卵裂率分别为６０．３和４６．８％，卵裂率在添加两种血清的培养基之间无显著差异。     

玉米源异麦芽寡糖菌质粉对黄羽肉鸡生长性能和激素分泌的影响

本研究在饲粮中分别添加 ３个不同剂量的玉米源异麦芽寡糖菌质粉（ＩＢＳ）,旨在研究其对黄羽肉鸡生长性能和内源性激素分泌的影响。选择 １日龄黄羽肉鸡 ２７０只,公母各占 １／２,随机分成 ５组。对照 １组饲喂基础饲粮,对照 ２组在基础饲粮中添加 ４．２７ｇ／ｋｇ市售食品级低聚异麦芽寡糖粉,试验 １、２、３组分别在基础饲粮中添加 ６、１２、２４ｇ／ｋｇＩＢＳ。结果表明：１）与对照 １组相比,试验 １、２、３组死亡率分别降低 ３３．３０％、４９．９５％、４９．９５％;１～５２日龄,试验 １、２、３组平均日增重分别提高 ８．８０％（Ｐ＜０．０１）、１１．０２％（Ｐ＜０．０１）、７．８０％（Ｐ＜０．０１）;试验 １、２、３组料重比分别降低 ８．７３％（Ｐ＜０．０５）、９．０９％（Ｐ＜０．０１）、６．９１％（Ｐ＜０．０５）;试验 ２组血清中甲状腺素含量提高 ８．６８％（Ｐ＜０．０５）;试验 ３组血清中胰高血糖素含量降低 ２４．７５％（Ｐ＜０．０５）;在血清胰岛素动态变化过程中,采食后 １ｈ,试验 １组提高 ４０．３１％（Ｐ＜０．０５）,采食后２ｈ,试验 ２组提高 ４０．０９％（Ｐ＜０．０５）;在血清生长激素动态变化过程中,采食后 １ｈ,试验 ３组提高 ３５．１８％（Ｐ＜０．０５）,采食后 ２ｈ,试验 ２、３组分别提高 ４８．２６％（Ｐ＜０．０５）、４２．７２％（Ｐ＜０．０５）;试验 ２、３组血清中生长激素含量总体平均值分别提高 ２３．６５％（Ｐ＜０．０５）、２６．２９％（Ｐ＜０．０５）。２）与对照２组相比,试验２、３组死亡率均降低２４．９７％;１～５２日龄,试验１、２、３组平均日增重分别提高 ６．５７％（Ｐ＜０．０５）、８．７５％（Ｐ＜０．０１）、５．５９％（Ｐ＜０．０５）;在血清胰岛素动态变化过程中,采食后 ２ｈ,试验 ２组提高 ４４．５５％（Ｐ＜０．０５）;在血清生长激素动态变化过程中,采食后 ２ｈ,试验 ２、３组分别提高 ５０．２４％（Ｐ＜０．０５）、４４．６３％（Ｐ＜０．０５）;试验 ３组血清中生长激素含量总体平均值提高 ２３．８０％（Ｐ＜０．０５）。结果提示,黄羽肉鸡饲粮中添加一定剂量的 ＩＢＳ,对其生长性能、激素分泌有促进作用,且在本试验的 ３个剂量中,以添加 １２ｇ／ｋｇＩＢＳ综合效果最佳。     

甲醛处理对蛋白质饲料保护效果的研究

豆饼、菜籽饼、菜籽分别用０．４％、０．６％、０．８％（ｇ／１００ｇＣＰ）甲醛处理后２４ｈ瘤胃干物质降解率（ＤＭＤ２４）分别从８０．２６％、７％、８４．０４％下降到６７．０７％、４８％、７７％；有机物降解率（ＯＭＤ２４）分别从８１．２３％、６９．５０％、８４．０９％下降到６８．２２％、５２．６％、７８．０５％；粗蛋白降解率（ＣＰＤ２４）分别从７２．４３％、７１．６１％、８９．８０％下降到４８．６６％     

14株苏云金芽孢杆菌伴胞晶体蛋白对猪蛔虫第3期幼虫的毒性比较

14株苏云金芽孢杆菌经培养提取伴胞晶体蛋白并测定其蛋白含量。感染性蛔虫卵经胃感染小鼠 ,3d后宰杀并从小鼠肝脏内分离蛔虫第 3期幼虫 (L 3)。设置空白对照 ,将不同剂量的 Bt伴胞晶体蛋白与 L 3置于培养孔在 37℃的二氧化碳培养箱中 (含 5 % CO2 )培养 ,间隔 12 h检查幼虫活性 ,计算死亡率、校正死亡率及半数致死量。L D50 随着作用时间的延长而逐渐减小。14株细菌伴胞晶体蛋白对 L 3的毒力差异很大。 0 17株对 L 3的杀虫作用快速而持久、毒力最强 ,其 L D50 是所有 14个菌株中最小的 ,作用 12、2 4和 36 h时分别为 1.135 7、0 .2 32 2和 0 .15 32 g/ L。     

在不同溶液和容器中短期保存牛体外受精胚胎的效果

为提高室温保存牛体外受精胚胎的效果，特进行了３个试验。试验一分别用３种保存液（ＰＢ１，ＴＣＭ－１９９，Ｈａｍ′ｓＦ－１０）、两种容器（玻璃试管，ＡＡ２０１塑料细管）在２０℃保存胚胎２４ｈ。结果表明，保存液对保存效果无显著影响，在３种保存液中保存第７、８天囊胚的总孵化率分别为７４．７％，７１．８％，７５．５％（Ｐ＞０．０５）。用试管保存的胚胎总孵化率（８３．６％）明显优于用ＡＡ２０１塑料细管保存的（６０．８％）（Ｐ＜０．０１）。试验二比较了用ＰＢ１在两种型号的细管（ＡＡ２０１，ＺＡ４７５）中保存胚胎的效果。胚胎在ＺＡ４７５细管中保存后的孵化率（８９．４％）显著高于在ＡＡ２０１细管中保存的（７６．３％）（Ｐ＜０．０１）。试验三用ＰＢ１在ＺＡ４７５细管中保存第７天囊胚３～７ｈ或１８～２４ｈ，将１枚胚胎移入已授精的、处于发情周期第７天的受体母牛黄体对侧的子宫角内。两组受体牛的妊娠率（分别为６０．３％，６８．３％）和双胎率（分别为４５．７％，６９．８％）均较高，而且差异不显著（Ｐ＞０．０５），说明胚胎可在ＺＡ４７５细管中成功地保存２４ｈ。     

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