饲料添加剂中微量游离锌的极谱测定

锌是畜禽必需的微量元素之一,它对畜禽的生长发育起着重要作用.准确测定饲料添加剂中锌的含量对饲料生产具有重要的指导意义.笔者发现,在0.01 mol/mL HCl-1.5%柠檬酸钠-0.3%抗坏血酸体系中,锌在峰电位为-1.03 V处产生了灵敏的还原极谱波,据此建立了单扫描示波极谱法直接测定饲料添加剂中微量游离锌的方法,该方法简便、快速、实用性强,应用于实际样品的分析效果较好.     

火焰原子吸收光谱法测定水牛和荷斯坦牛乳中锌、铁、铜含量

研究采用火焰原子吸收分光光度法(FAAS法)测定水牛和荷斯坦牛乳中锌、铁、铜含量.结果表明,锌、铁、铜含量在水牛乳中分别为15.520 μg/mL、4.267μg/mL、0.586μg/mL,在荷斯坦牛乳中分别为4.374 μg/mL、2.756μg/mL、0.866 μμg/mL.水牛乳中锌、铁含量极显著高于荷斯坦牛...     

JP-303D智能极谱法同时测定化探样品中微量钨钼

钨和钼可以在氯酸盐-苯羟乙酸-硫酸-辛可宁体系中分别能产生灵敏度较高、跨度较大的极谱催化波。本文采用1mL(1+1)硫酸+1mL高氯酸+20mL(1+1)王水湿法消解化探样品,再用150g/L氢氧化钠溶液浸提,智能极谱法同时测定钨和钼。该方法快速简单、准确,适用于化探样品中微量钨钼元素的同时测定,并已实际应用于大批量样品分析检测。     

气相色谱-质谱法测定猪肉中的莱克多巴胺

建立了气相色谱-质谱法（GC-MS）测定猪肉中莱克多巴胺残留的方法.用乙腈提取试样中的莱克多巴胺,经SLH固相萃取柱净化,氮气吹干,衍生化后进行气相色谱-质谱法测定.猪肉中莱克多巴胺的检出限为0.5μg/kg,定量限为2.0μg/kg.溶液中莱克多巴胺浓度在0.02～1.0μg/mL范围内,峰面积与之呈良好的线性关系.平均回收率在81.4%以上,批内相对标准偏差小于8.4%.     

高效液相色谱法测定猪血浆中阿莫西林含量

建立了高效液相色谱法测定猪血浆中阿莫西林含量的方法.采用Agillent1100HPLC系统,色谱柱为SB C18,流动相为0.05 mol/L磷酸二氢钾-0.1 mol/L三乙胺-乙腈(800:120:7,pH 2.5),流速1.0 mL/min,柱温30℃,检测波长220 nm.猪血浆样品经高氯酸溶液变性处理,取上清液直接进样测定.阿莫西林的色谱峰面积对其浓度的线性关系范围在0.5～20.0μg/mL之间,相关系数为0.999 7.阿莫西林低、中、高(0.5,5.0,20.0μg/mL)三种添加浓度猪血浆样品的平均加样回收率分别为100.7%、105.1%、103.3%(n=3),变异系数分别为3.0%、0.1%、3.3%(n=3).该法可用于猪血浆中阿莫西林含量的测定和相关的药代动力学研究.     

高效液相色谱法测定赛鸽用复方吡喹酮胶囊中吡喹酮和伊维菌素的含量

用高效液相色谱法同时测定赛鸽用复方吡喹酮胶囊中吡喹酮和伊维菌素的含量.采用Nova-Pak C18柱(150 mm×3.9 mm,4 μm),以乙腈-甲醇-水(53:35:12)为流动相,流速为1.0 mL/min,检测波长254 nm,柱温25℃.在此色谱条件下,吡喹酮和伊维菌素的分离良好,吡喹酮和伊维菌素分别在511～1 534μg/mL和10.1～30.6μg/mL浓度范围内峰面积与浓度呈良好的线性关系(r＞0.999).按外标法以峰面积计算进行测定,吡喹酮和伊维菌素的平均回收率分别为99.9%和98.3%,RSD分别为0.3%和0.6%(n=9).本方法简便、快速、准确,适用于赛鸽用复方吡喹酮胶囊中吡喹酮和伊维菌素含量的测定.     

饲料中添加沼液喂猪时铜的迁移规律研究

对沼液中含铜量及饲料中添加沼液喂猪对猪日增重、料肉比和肝脏、肌肉、粪便中含铜量的影响进行了研究。采用GB13885-91方法,间隔30 d三次测定沼液中铜含量,结果分别为0.13μg/mL、0.16μg/mL和0.18μg/mL,试验设3个添加沼液处理,饲料与沼液的比例分别为1∶0.5、1∶1和1∶1.5,进行饲养试验,并采用GB13885-91方法对猪肌肉、肝脏及粪铜含量测定。结果：饲料中添加1∶1和1∶1.5的沼液,日增重极显著高于对照组和饲料中添加1∶0.5的沼液组,饲料中添加1∶1的沼液组日增重极显著高于饲料中添加1∶1.5的沼液组;饲料中添加沼液显著提高了肝脏、肌肉和粪便中铜含量,且随着沼液添加量的增加,肝脏、肌肉和粪便中含铜量随之增加。说明肝脏、肌肉和猪粪中含铜量与饲粮的含铜量是密切相关的,饲料中添加沼液喂猪可以降低饲料中铜的添加量。     

饲料中添加沼液喂猪时铜的迁移规律研究

对沼液中含铜量及饲料中添加沼液喂猪对猪日增重、料肉比和肝脏、肌肉、粪便中含铜量的影响进行了研究。采用GB13885-91方法,间隔30 d三次测定沼液中铜含量,结果分别为0.13μg/mL、0.16μg/mL和0.18μg/mL,试验设3个添加沼液处理,饲料与沼液的比例分别为1∶0.5、1∶1和1∶1.5,进行饲养试验,并采用GB13885-91方法对猪肌肉、肝脏及粪铜含量测定。结果：饲料中添加1∶1和1∶1.5的沼液,日增重极显著高于对照组和饲料中添加1∶0.5的沼液组,饲料中添加1∶1的沼液组日增重极显著高于饲料中添加1∶1.5的沼液组;饲料中添加沼液显著提高了肝脏、肌肉和粪便中铜含量,且随着沼液添加量的增加,肝脏、肌肉和粪便中含铜量随之增加。说明肝脏、肌肉和猪粪中含铜量与饲粮的含铜量是密切相关的,饲料中添加沼液喂猪可以降低饲料中铜的添加量。     

“一针肥注射液”中微量元素含量测定方法的建立

目的：建立＂一针肥注射液＂中微量元素的含量测定方法。方法：采用火焰原子吸收分光光度法测定＂一针肥注射液＂中铁、锌、铜、硒、钴的含量。结果：铁、锌、铜、硒、钴的线性范围分别为0.053~0.385μg/mL、0.25~2.50μg/mL、0.5~8.0μg/mL、10.0~100.0ng/mL、5.0~50.0ng/mL,平均回收率分别为100.35%、99.95%、99.51%、98.49%、100.51%。结论：本法可以准确测定＂一针肥注射液＂中铁、锌、铜、硒、钴的含量,该法简便、快速、准确可靠。     

高效液相色谱法测定饲料中替米考星含量

本实验建立了测定饲料中替米考星含量的高效液相色谱(HPLC)检测方法。将2g饲料样品,经乙腈、乙腈-磷酸二氢钾缓冲液提取后过C18萃取柱净化、蒸干、流动相溶解后进行HPLC检测分析。流动相检测波长为290nm,流速1.0mL/min。结果表明:在1～500μg/mL的浓度范围内替米考星的峰面积(顺式和反式异构体的峰面积之和)与浓度呈良好的线性关系(r=1),平均回收率为81.4%以上,RSD小于6.1%,检测限为1μg/g。     

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