黄牛血清流变学7项主要指标的测定

应用锥板式粘度计和红细胞电泳仪对３１头健康黄牛血液流变学７项指标进行测定。结果：全血粘度０．２ｃｍ＝ｓ·３．０９±３．３９ｍＰａ·ｓ，０．５ｃｍ／ｓ时３．６６±３．２９ｍＰａ·ｓ，２ｃｍ／ｓ时４．８８±３．３５ｍＰａ·ｓ，５ｃｍ／ｓ时５．３８±３．１７ｍＰａ·ｓ，２０ｃｍ／ｓ时５．５１±２．１２ｍＰａ·ｓ，５０ｃｍ／ｓ时４．８４±２．３０ｍＰａ，１００ｃｍ／ｓ时３．４２±０．９７ｍＰａ·ｓ；全血比     

双波长光度法测定饲料中钙

本文提出了饲料中钙的测定的新方法，试验表明，在ｐＨ１０．５～１１．５的氨－氯化铵缓冲介质中，钙与三溴偶氮胂形成稳定的紫色配合物，在波长６０５ｎｍ处有最大吸收，表现摩尔吸光系数ε＿（６０５）＝２．３×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），检测的线性范围为５～６５μｇ／５０ｍｌ。进一步利用双波长光度法可使方法灵敏度提高到ε＿（４９０～６０５）＝３．５×１０￣４Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）。本方法用于饲料样品的测定，结果与国家标准法相符，并明显优于ＥＤＴＡ配位滴定法。     

猪核移植重组胚胎的发育能力

以ＭｃＧｒａｔｈ－Ｓｏｌｔｅｒ（１９８３）提供的去（注）核方法，将猪胚胎的单个卵裂球细胞注入去核的次级成熟卵母细胞，借助电融合的方法（ＡＣ；５Ｖ，１．５ＭＨｚ，１２－１５ｓ；ＤＣ：２ｋＶ／ｃｍ，４０μｓ。电激活／融合液：０．３ｍｏｌ／Ｌ甘露醇＋－．１ｍｍｏｌ／ＬＭｇＳＯ４＋０．１ｍｍｏｌＣａｃＬ２＋７．５ｍｇ／ｍｌＣＣＢ）融入受体胞质构成重级胚，体外培养（培养液为改衣ＴＣＭ－１９９；培养条件为５％     

家蚕RAPD的扩增条件、重复性及遗传模型研究

发现当ＰＣＲ体系中Ｍｇ￣（２＋）为２ｍｍｏｌ／Ｌ、ｄＮＴＰｓ为１５０μｍｏｌ／Ｌ、Ｔａｇ酶为１Ｕ、引物为０．２μｍｏｌ／Ｌ时，以４０～４２℃退火可得到稳定结果；８％的ＤＭＳＯ对提高扩增特异性有利；分别从蚕卵、蚁蚕、５龄蚕丝腺、体壁及生殖腺、蛹、蛾中提取模板ＤＮＡ，其ＲＡＰＤ结果一致；以Ｃ＿（１０８）×大造为材料，发现其Ｆ＿１ＲＡＰＤ为共显性。     

台湾芒草之光合作用特性

芒草为Ｃ４型植物，叶片上表皮气孔数目很少，高山所产者尤甚，而且产于高山的芒草，其叶片上表皮覆盖一层可能是角质层的物质，不容易分辨表皮细胞，而产于低海拔者则否。其ＣＯ２补偿点，除了高山芒接近９ｐｐｍ之外，其余在３．５～６．５ｐｐｍ。光合成率对光度之反应呈饱和曲线。在未施氮区，芒草单叶之饱和点为７５０～１２５０μＥ／ｍ＾２／ｓ，其最光合（Ｐｎ介于８－１６μｍｏｌＣＯ２／ｍ＾２／ｓ之间，每盆施氮２ｇ，１     

青海（黑）牦牛的血清钙指标分析

对１０６头青海黑牦牛的血清钙分析结果表明：①ＳＴＣａ、ＳＢＣａ和ＳＦＣａ％分别为２．５５±０．２２ｍ ｍｏｌ／Ｌ、０．９７±０．２５ｍ ｍｏｌ／Ｌ、１．６０±０．１６ｍｍｏｌ／Ｌ和３７．２２％。②ＳＴＣａ和ＳＦＣａ间，ＳＴＰ和ＳＢＣａ间，均呈极显著正相关（Ｐ〈０．０１），回归方程分别为ｙ＝－１．２５６１＋０．８７１９ｘ。     

笼养乌骨鸡人工授精技术的研究

我们于１９９６年４￣６月对笼养１０￣１２月龄种用乌骨鸡进行人工授精技术研究。其结果：乌骨鸡精液颜色为乳白色，射精量为０．４９±０．２３８ｍｌ；精子密度２０．３±１０．８４×１０＾８／ｍｌ；精子的畸形率（５．７９±１．６４）％。乌鸡骨精子形态与家鸽同，精子总长度为（８０．５９±３．９４）μｍ，头为弯园柱状，直径０．５μｍ，头长约８μｍ，精子头部前端为顶林，长约２μｍ，尾部（中、主、末段）长７１±２．     

桑尺蠖和丝棉木金星尺蠖的微孢子虫对家蚕病原性和胚种传染性研究

从桑尺蠖（ＨｅｍｅｒｏｐｈｉｌａａｔｒｉｌｉｎｅａｔａＢｕｔｌｅｒ）中分离的微孢子虫（简称桑尺蠖微孢子虫），形态为长卵圆形，大小为３．５～４．１×１．６～１．９μｍ。从丝棉木金星尺蠖（ＣａｌｏｓｐｉｌｏｓｓｕｓｐｅｃｔａＷａｒｒｅｎ）中分离的微孢子虫（简称丝棉木金星尺蠖微孢子虫），形状为卵圆形，大小为３．２～３．７×１．６～２．１μｍ。两种微孢子虫均能感染寄生家蚕的主要组织器官，引起蚕儿发病，但致病力要比家蚕微孢子虫（Ｎｏｓｅｍａｂｏｍｂｙｃｉｓ）弱，且能经卵传染给下一代，其胚种传染率要比家蚕微孢子虫低。     

双氢除虫菌素对家兔和豚鼠螨病的疗效与药理学特征

对耳部感染兔痒螨的家兔采取４００μｇ／ｋｇ剂量的双氢除虫菌素皮下注射，其临床分级显著降低。对由ＴｒｉｘａｃａｕｒｕｓＣｕｖｌａｅ引起螨病的豚鼠以５００μｇ／ｋｇ双氢除虫菌素皮下注射，得到临床治愈。家兔皮下注射４００μｇ／ｋｇ双氢除虫菌素，组织和体液中产生高而持久的浓度至少达１３天。其在组织中衰减速率与在绵羊和大鼠中观察到的情况相似。在用药３７．２±５．０小时血浆中的平均（±平均标准误）峰值浓度为４２．０±９．ｎｇ／ｍｌ。药时曲线下面积（ＡＵＣ）为３５４３±５８０μｇ／ｍｌ·ｈ，给豚鼠口服、皮下注射或局部用５００μｇ／ｋｇ剂量的双氢除虫菌素，只有皮下注射能测出血浆中药物浓度。在用药后７２小时，四只豚鼠的平均浓度为０．７±０．３ｎｇ／ｍｌ。     

公雏鸡肾上腺去除及其对地塞米松和RU_(486)的反应

应用电灼烧和强酸腐蚀的方法成功地对１０ 周龄公雏鸡实行了肾上腺去除术。在此基础上对完全去肾上腺雏鸡给以外源性糖皮质激素（ Ｇ Ｃ）地塞米松（ Ｄｅｘ）２ ｍ ｇ／ｋｇ·ｄ可以逆转由于 Ｇ Ｃ 缺失造成的血糖降低和水盐代谢紊乱。对去除１ ２３肾上腺雏鸡并给以 Ｒ Ｕ４８６ Ｐ Ｖ Ａ ５０ ｍ ｇ／ｋｇ·ｄ，雏鸡血糖、血清钠，血清钾维持正常水平；虽然其血清 Ａ Ｃ Ｔ Ｈ 浓度升高至（１４６． ９４±７．５６） Ｉ Ｕ／ Ｌ（ Ｐ＜ ０．０１），但血清皮质酮并没有在高浓度 Ａ Ｃ Ｔ Ｈ 刺激下大量分泌而维持于９０．４８～１０３．１４ ｎｍ ｏｌ／ Ｌ 的生理范围内。为在不受内源性 Ｇ Ｃ干扰下建立鸡糖皮质激素受体（ Ｇ Ｒ）阻断提供了实验动物模型。     

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