饲料中呋喃唑酮的HPLC法测定

建立了高效液相色谱（HPLC）法测定饲料中违禁药物呋喃唑酮的含量。饲料中呋喃唑酮用乙腈-甲醇（1：1，V／V）提取，中性氧化铝SPE柱净化。呋喃唑酮的线性范围为0．02～1.0μg／mL（r=0．9999），3种加药浓度进行回收率测定，回收率为86．3％～104．5％之间，批内变异系数小于1．10％，本方法的最低检测限为0．5μg／g。     

索氏抽提残余法与ANKOM滤袋法检测饲料粗脂肪含量的比较

为了比较索氏抽提残余法与ANKOM滤袋法测定饲料中粗脂肪含量的准确性与检测效率,试验从河北省和天津市的饲料加工厂采集12份饲料样品,采用索氏抽提残余法和ANKOM滤袋法同时对试验样品粗脂肪含量进行测定。结果表明:2种方法测定结果的相对偏差均在3%以下,符合《饲料中粗脂肪的测定》(GB/T 6433—2006)~([6])的要求;索氏抽提残余法和ANKOM滤袋法的差值在-0. 16～0. 32之间,比值在96. 57%～101. 94%之间,检测结果基本一致;经配对样本t检验,测定结果差异不显著(P0. 05)。说明二种方法均能准确检测出样品中粗脂肪含量,但索氏抽提残余法检测效率较低,而ANKOM滤袋法操作简易,检测效率较高,是值得推广的检测方法。     

HPLC法测定饲料中喹乙醇残留及应用HPLC法测定饲料中喹乙醇残留及应用

HPLC法测定饲料中喹乙醇的残留，具有很好的分离度，浓度10～100μg／mL范围呈良好的线性关系，R=0．99998，回收率范围为85．8％～99．4％，批内变异系数≤5．7％，批间变异系数≤1．1％。实践中检测24批鸡配合饲料，喹乙醇残留未检出，检测62批鱼饲料，喹乙醇残留检出率为8．1％，检出的样品中，残留量范围为19．7～42．0mg／k。表明鱼饲料中存在喹乙醇残留隐患。     

不同粉碎粒度的饲料对滤袋法测定纤维物质含量的影响

本试验旨在研究不同粉碎粒度的饲料对滤袋法测定饲料中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)、中性洗涤不溶蛋白(NDIP)及酸性洗涤不溶蛋白(ADIP)含量的影响。采集黑龙江、河南及河北3个省的30个不同种类的饲料样品,分为5类(干草类饲料、农副产品类饲料、青贮类饲料、糟渣类饲料和饼粕类饲料),各类饲料分别粉碎为2个处理长度,粗粉碎组为2.00 mm,细粉碎组为0.45 mm(过40目分析筛),测定各样品的NDF、ADF、NDIP和ADIP含量。结果显示:1)粗粉碎组和细粉碎组的干草类饲料、饼粕类饲料NDF含量差异极显著(P<0.01);2组间干草类饲料、青贮类饲料ADF含量差异极显著(P<0.01),糟渣类饲料、饼粕类饲料ADF含量差异显著(P<0.05)。粗粉碎组饲料的NDF和ADF含量普遍高于细粉碎组。2)粗粉碎组和细粉碎组的NDIP含量除青贮类饲料差异显著(P<0.05)外,其余几类饲料的NDIP含量差异均不显著(P>0.05);2组间各类饲料的ADIP含量差异均不显著(P>0.05)。结果提示,采用滤袋法测定不同粉碎粒度的饲料NDF和ADF含量差异较大,建议采用2.00 mm的粉碎粒度进行测定;采用滤袋法测定不同粉碎粒度的饲料NDIP和ADIP含量差异较小。     

林可霉素在饲料中残留的微生物学检测方法

建立了林可霉素在配合饲料中残留的微生物学检测方法。样品用二氯甲烷提取经浓缩、溶剂转换．制成试样溶液，再用藤黄微球菌作为检定茼进行含量测定。结果显示。林可霉素在0．15-2．4μg／ml的浓度范围内具有良好线性关系（r=0．9991）。配合饲料中3种添加浓度1．00μg／g、400μg／g、8．00μg／g的平均回收率为80．2％（n=9）。RSD分别为5．7％、4．2％、2．2％（n=3）。     

松针粉饲喂肉兔的效果研究

松针粉是在抚育幼林时，将修剪下来的幼嫩枝条和针叶收集起来，经过干燥、粉碎而成。松针粉色绿、幽香，是近年来人们正在开发的一种营养价值较高的畜禽饲料添加剂。据测定，松针粉中胡萝卜素含量一般在69—356mg／kg、维生素C含量约为950～2203mg／kg、维生素E含量一般在201～1266mg／kg、蛋白质含量8％-11．9％、粗脂肪含量3．8％-13．1％，含有的微量元素多达40余种，比苜蓿草含有的微量元素还要丰富。     

林麝饲用植物叶常规营养成分分析

用国标规定的饲料常规养分分析方法对林麝喜食的勾儿茶等24种野生植物叶样品中的干物质、粗蛋白质、粗纤维、粗脂肪、粗灰分、总能进行测定,并将测定结果与泡桐、苜蓿的营养成分进行比较。结果表明,这些样品的粗蛋白含量介于8．4％～27．4％之间,其中构树、律草、桑的蛋白含量均高于泡桐、苜蓿,分别为27．4％、22．3％、19．0％;干物质含量介于90．1％～93．5％之间,粗脂肪含量介于0．8％～7．1％之间,粗纤维含量介于7．8％～23．0％之间,粗灰分含量介于4．8％～13．2％之间,总能介于14．38～19．73MJ／kg之间。这将为林麝的饲养管理及其营养基础研究提供一定的依据。     

微量Bradford法测定提纯禽结核菌素蛋白含量

研究用96孔微量板Bradford法测定提纯禽结核菌素蛋白含量。通过不同浓度的待测禽结核菌素与考马斯亮蓝G-250溶液混合后，在595nm光波下测定各孔样品的OD值。微量Bradford法检测禽结核菌素的线性范围是50—1000μg／mL，相关系数为0．999，最低定量限为50μg／mL。试验用3支禽结核菌素国际参照品，分别配制成125、250、500μg／mL三种不同浓度，每支每种浓度测定4次，计算实际测得的蛋白质浓度。结果显示，批内相对标准偏差为1．6％～4．4％；批间相对标准偏差0．7％-2．2％。研究结果表明微量Bradford法可作为测定禽结核菌素蛋白含量的一种方法。     

饲料中糖皮质激素类药物含量的UPLC—MSJ／MS检测方法的研究

试验建立了饲料中9种糖皮质激素类药物含量的UPLC—MS／MS检测方法。饲料中的糖皮质激素类药物经甲醇振荡提取，浓缩蒸干，溶解后用碳黑固相萃取柱串接氨基固相萃取柱净化后，液相色谱一串联质谱法测定，外标法定量。9种药物在2～100．g／ml浓度范围内呈线性相关，相关系数在0．997～0．9995，方法在饲料中最低检测限（LOD）为2μg／kg；定量限（LOQ）为5μg/kg。此方法在空白饲料中添加5～20ng／g浓度范围内，平均回收率在55．1％～88．2％，批内变异系数为3．3％～19．1％，批间变异系数为4．2％～13．5％。该方法具有较好的灵敏度、准确度和精密度，能完全满足饲料中此类药物含量的检测，可以作为此类药物的标准化检测方法。     

一种提取蛹蛋白的新方法初探

本试验以蚕蛹为原料，用石油醚浸出法提取蛹油制备脱脂蛹，然后采用有机溶剂法，以30％乙醇生理盐水为溶剂提取蛹蛋白，并对蛹蛋白的质量进行了检测。研究结果表明：脱脂蛹的含量约占干蛹含量的70％；提取蛹蛋白最佳抽提条件为：温度70℃、浴比1：15、时间2h，蛹蛋白的得率为8．47％；蛹蛋白的颜色为浅褐色．几平无蛹臭味．     

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     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

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

Tropical Animal Health and Production -