混合型饲料添加剂液态亚洲薄荷素油·桉叶油含量检测方法研究

建立可同时测定混合型饲料添加剂中薄荷脑和1,8-桉叶素含量的气相色谱法。方法采用乙醇溶解、定容后,经毛细管气相色谱分离,氢火焰离子化检测器测定,外标法定量。研究结果表明,目标化合物薄荷脑、1,8-桉叶素在0.01～10 mg/mL浓度具有良好线性关系,相关系数为r≥0.9990;检出限分别为10 mg/L、15 mg/L。薄荷脑,准确度:回收率为109.7%～117.4%,精密度RSD=0.83%(n=6);1,8-桉叶素,准确度:回收率为84.1%～89.7%,精密度RSD=2.48%(n=6)。该方法简便快捷,灵敏度和准确均较高,加标回收率高,重现性好;操作简单,使用仪器设备普及率高。可用于混合型饲料添加剂液态亚洲薄荷素油·桉叶油样品中薄荷脑和1,8-桉叶素的测定。     

气相色谱法检测混合型饲料添加剂中的大蒜素和香芹酚

建立了检测混合型饲料添加剂中大蒜素和香芹酚含量的气相色谱方法。样品采用乙醇提取,经毛细管相色谱柱(HP-5,30m×0.32mm×0.25μm)分离,氢火焰离子化检测器测定,外标法定量,并采用气质确证。方法学研究结果表明,目标化合物二烯丙基二硫醚,二烯丙基三硫醚,香芹酚在0.01~10 mg/m L浓度范围内具有良好线性关系,相关系数为r≥0.9990,检出限分别为10mg/kg、15mg/kg、10mg/kg;回收率为79.8%~96.2%,相对标准偏差为2.61%~4.73%。该方法前处理简单,准确可靠,灵敏度可以用于混合型饲料添加剂样品中大蒜素和香芹酚进行测定。     

高效液相色谱紫外检测法测定饲料中N-氨甲酰谷氨酸的含量

本实验建立了高效液相色谱紫外检测法测定饲料中N-氨甲酰谷氨酸含量的方法。配合饲料样品用水提取后经混合型阴离子固相萃取柱净化富集。以甲醇-0.05%磷酸水溶液(V/V,5∶95)为流动相,C18色谱柱分离,检测波长215 nm。结果表明,在1.5~500μg/m L浓度范围线性关系良好,R2=1,样品回收率为88.6%~101.2%,相对标准偏差为0.69%~2.31%(n=5),定量限为0.075 mg/g。可见本方法适用于饲料中N-氨甲酰谷氨酸的含量测定。     

高效液相色谱法测定混合型饲料添加剂中肉桂醛、丁香酚、香芹酚和百里香酚含量

研究建立了同时测定混合型饲料添加剂中肉桂醛、丁香酚、香芹酚和百里香酚含量的液相色谱方法。混合型饲料添加剂样品用甲醇提取,以C_(18)柱(150 mm×4.6 mm×5μm)为分析柱,紫外检测器检测,外标法定量。结果表明:在所选择的色谱条件下,空白载体中肉桂醛、丁香酚、香芹酚和百里香酚能达到很好的分离;丁香酚、香芹酚和百里香酚在1.0～500 mg/L内线性关系良好,肉桂醛在0.10～50.0 mg/L内线性关系良好;丁香酚、香芹酚和百里香酚最低定量限为50 mg/kg,肉桂醛最低定量限为5.0 mg/kg;加标回收率为83.7%～112%,变异系数为0.70%～6.39%。该方法样品前处理简单、简便可靠,可用于混合型饲料添加剂中肉桂醛、丁香酚、香芹酚和百里香酚的同步检测。     

气相色谱法检测饲料添加剂中的柠檬醛、D-柠檬烯和甲基庚烯酮

建立了气相色谱方法同时测定混合型饲料添加剂中甲基庚烯酮、D-柠檬烯、柠檬醛(包括橙花醛和香叶醛)含量的分析方法。样品采用乙酸乙酯提取,经毛细管气相色谱柱(ZB-5,30m×0.32mm×0.25μm)分离,氢火焰离子化检测器测定,外标法定量,并对目标化合物采用气质确证。方法学研究结果表明:目标化合物甲基庚烯酮、D-柠檬烯、橙花醛和香叶醛在0.01～10 mg/m L浓度范围内具有良好线性关系,相关系数为R~2≥0.9990,方法的定量限在0.02～0.04g/kg,回收率为81.3%～108.5%,相对标准偏差为2.01%～4.88%。该方法简便、快速、准确,可以用于饲料添加剂样品中甲基庚烯酮、D-柠檬烯、橙花醛和香叶醛含量的测定。     

混合型饲料添加剂中1,8-桉叶素和松油烯-4-醇含量检测方法研究

建立了同时检测茶树油混合型饲料添加剂中1,8-桉叶素和松油烯-4-醇含量的气相色谱方法。样品采用乙醇提取,经毛细管相色谱柱(ZB-35,30m×0.32mm×0.25um)分离,氢火焰离子化检测器测定,外标法定量,并采用气质确证。方法学研究结果表明,目标化合物1,8-桉叶素和松油烯-4-醇在0.01~10 mg/m L浓度范围内具有良好线性关系,相关系数为r≥0.9990,检出限分别为15mg/kg、10mg/kg;回收率为80.8~102.5%,相对标准偏差为2.23~4.57%。该方法简便、快捷,灵敏度和准确度均较高可以用于茶树油混合型饲料添加剂样品中1,8-桉叶素和松油烯-4-醇的测定。     

混合型饲料添加剂中硫酸黏杆菌素的液相色谱检测方法研究

本研究建立了混合型饲料添加剂中硫酸黏杆菌素含量的液相色谱检测方法。混合型饲料添加剂样品用5%草酸提取,经离心和HLB小柱净化,用丹磺酰氯柱前衍生,以C_8柱(150 mm×4.6 mm×5μm)为分离柱,荧光检测器在激发波长344 nm,发射波长518 nm下进行检测。结果表明:在所选择的色谱条件和衍生条件下,硫酸黏杆菌素A在0.025～10.0μg/mL时线性关系良好,最低定量限为2 mg/kg;添加回收率为85.1%～108%,变异系数为0.84%～5.52%。本方法样品前处理简便、可靠,可用于混合型饲料添加剂中硫酸黏杆菌素的检测。     

反相高效液相色谱法测定饲料及饲料添加剂中阿朴酯的含量北大核心

研究旨在建立一种反相高效液相色谱(RP-HPLC)法检测饲料及饲料添加剂中阿朴酯含量的方法。饲料或饲料添加剂样品经水、甲基叔丁基醚-甲醇溶液提取,样液在50℃水浴中经氮气吹干(添加剂样品直接稀释),使用流动相稀释,定容,上机检测。结果显示,采用C30色谱柱、流动相甲基叔丁基醚-甲醇比例为15∶85时,阿朴酯能够与其他类胡萝卜素很好地分离。试验所用方法在0.04~10.00 mg/L浓度范围内线性关系良好,相关系数为0.999 98。样品中添加阿朴酯的加标回收率为86.0%~99.8%,方法检出限为0.15 mg/kg,方法定量限为0.40 mg/kg。研究表明,试验所用方法操作简单、灵敏度高,能够检测饲料及饲料添加剂中的阿朴酯。     

HPLC测定混合型饲料添加剂中L-苹果酸含量

用HPLC法测定混合型饲料添加剂中L-苹果酸(malic acid,LMA)的含量。采用C18(250 mm×4.6 mm×5μm)色谱柱,以0.02 mol/l磷酸二氢钾:乙腈=982(v:v),流速0.8 ml/min,柱温25℃,检测波长210 nm,进样量10μl。结果表明:L-苹果酸对照品和样品的保留时间均是3.9 min,其线性方程分别为Y=0.390 9X-4.578 6,R=0.999 8(n=5),在126.25~2 020μg/ml的范围内,线性关系良好,其最低检测量为12.23μg/ml。精密度的RSD为0.43%,表明此方法精密度较好;重现性的RSD为0.17%,表明重现性良好;回收率的RSD为0.61%。用此方法检测出其混合饲料添加剂中L-苹果酸含量为(99.01±0.11)%,符合产品规定的质量要求。该实验建立的HPLC方法可快速、准确测定混合饲料中L-苹果酸含量,为其质量控制提供科学依据。     

高效液相色谱紫外检测法测定添加剂预混合饲料中叶酸含量

本实验建立了添加剂预混合饲料中叶酸测定的高效液相色谱紫外检测测定方法。样品经碳酸钠溶液提取,通过阴离子交换柱净化富集,高效液相色谱紫外法测定。结果表明:叶酸浓度为0.1~250.0μg/m L时,具有良好的线性关系,样品回收率为79.9%~100.4%,相对标准偏差小于10%,定量限可达0.3 mg/kg,适用于添加剂预混合饲料中叶酸含量的测定。     

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.     

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     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -