恩诺沙星固体分散剂在肉鸡组织中残留的研究

为了研究恩诺沙星固体分散剂在肉鸡组织中的残留情况,试验选择150只1日龄AA肉鸡,试验组喂养至35日龄在饮水中添加75 mg/L恩诺沙星固体分散剂,自由饮水,连续用5 d后休药,采集不同时间的样本用高效液相色谱法(HPLC)进行检测。结果表明:休药第5天,肝脏、胸肌及脂肪组织中药物总残留量(恩诺沙星+环丙沙星)分别为(77.07±15.21),(12.56±9.65),(26.36±11.72)μg/kg,而肾脏组织中未检出;休药第7天,肝脏、肾脏、胸肌及脂肪组织中均未检出恩诺沙星及环丙沙星。采用WT 1.4软件处理试验数据,肝脏、肾脏、胸肌和脂肪的休药期(WDT)分别为5.92,4.36,5.21,5.63 d。说明肉鸡按照推荐剂量饮水给药,建议休药期至少为6 d。     

盐霉素在肉鸡组织中残留消除规律研究

选择250只1日龄"AA"肉鸡,每1 kg饲料中添加70 mg的盐霉素钠,自由采食,混饲至42日龄停药.停药0 h,肉鸡胸肌、肝脏、脂肪和肾脏中盐霉素含量分别为97.17、371.43、154.4和50.33μg/kg,休药48 h后,肉鸡组织中未检出盐霉素,证明国家规定的5 d休药期是合理的.     

恩诺沙星混悬液的研制及其在鸡组织中的残留研究

以恩诺沙星为主药,采用正交试验筛选配方,研制恩诺沙星混悬液,并对该制剂的药剂学特征及其在鸡组织中的残留进行研究。药剂学研究表明,混悬液的性状、pH及药物含量均符合混悬剂质量要求,且稳定性良好、易于再分散。健康鸡在饮水中添加75 mg/L(以恩诺沙星计)混悬液,自由饮水,连续用药5 d后休药;休药第5天,肌肉、肝脏及"皮肤+脂肪"组织中药物总残留量(恩诺沙星+环丙沙星)分别为11.12±10.53、79.29±28.86、50.08μg/kg±22.09μg/kg,而肾脏组织未检出;休药第8天,肌肉、肾脏、肝脏组织中均未检出恩诺沙星及环丙沙星,"皮肤+脂肪"的总残留量为13.84μg/kg±10.82μg/kg。采用WT1.4软件处理数据,计算出该混悬液在鸡体内的休药期为6 d。     

鸡白痢与球虫病混合感染的诊断与治疗

我市某养鸡专业户养有3000只肉鸡,实行地面育雏.据户主讲:7 日龄接种了新城疫Ⅳ系疫苗,8～10日龄在饮水中加入0.005%的恩诺沙星,13 日龄接种了传染性法氏囊病疫苗,16日龄脱温分群.     

糖萜素代替药物添加剂对肉鸡生产性能的影响

选同一父母代种鸡场1日龄AA苗鸡1000只,分成对照组和试验组2组.对照组饲喂基础日粮中添加抗生素(每千克饲料添加杆菌肽锌16.7 mg 硫酸粘杆菌素3.3 mg),并在饲养过程中按常规饮水给药;试验组饲喂基础日粮中添加糖萜素(1～28日龄550 mg/kg,29～56日龄400 mg/kg),在饲养过程中不使用预防药物.试验结果表明,肉鸡日粮中添加糖萜素后,成活率、平均体重、饲料转化率和经济效益均略好于在日粮和饮水中添加抗生素等药物的对照组,说明在肉鸡生产中,可以用糖萜素代替药物添加剂,生产无公害甚至绿色肉鸡产品.     

恩诺沙星对肉仔鸡胫骨关节软骨的影响

为了探究氟喹诺酮类药物恩诺沙星对禽类胫骨发育的影响,以恩诺沙星为研究对象,选取雄性肉鸡鸡雏,随机分成5组,分别为空白组、10 mg/kg体重组、30 mg/kg体重组、60 mg/kg体重组、100 mg/kg体重组,每组36只,于1日龄和7日龄进行相应的给药处理,在7、14、21、28、35、42 d每组随机抽取6只肉鸡,取部分胫骨关节软骨做组织切片用,观察胫骨关节软骨组织结构变化并记录关节软骨细胞数量,评价胫骨关节软骨的发育情况。结果表明,恩诺沙星对肉鸡胫骨关节软骨的组织结构影响不显著,静止区软骨细胞和肥大区软骨细胞在不同生长时期时,不同剂量恩诺沙星对其细胞数量影响差异不显著。     

一起鸡白痢与球虫混合感染的诊治

1发病情况朝阳县黑牛乡务本村某养鸡户2011年7月饲养的2 000只肉鸡,实行地面育雏。主诉7日龄接种新城疫IV系疫苗,8～10日龄在饮水中加入0.005%恩诺沙星,13日龄接种传染性法氏囊病疫苗,16日龄脱温分群。2天后,发现个别鸡只精神沉郁,羽毛松乱,头下低,双翅下垂,不愿走动,闭目打盹,肛门周     

妥曲珠利对肉鸡生长性能和免疫机能的影响

本试验旨在研究饮水中添加不同水平妥曲珠利对肉鸡生长性能和免疫机能的影响.288只1日龄AA肉仔鸡,随机分为4组.各组日粮相同,对照组(1组)饮用自来水,试验组(2组、3组和4组)于8～10日龄连续3d饮水中分别添加妥曲珠利25mg/L、50 mg/L和100 mg/L,试验期42 d.结果表明,妥曲珠利对肉鸡生长性能和血清新城疫抗体效价均无显著影响(P＞0.05);25mg/L和50 mg/L妥曲珠利组肉鸡28日龄胸腺指数和脾脏指数显著高于对照组(P＜0.05),100mg/L妥曲珠利组肉鸡28日龄腔上囊指数显著低于对照组(P＜0.05);50 mg/L妥曲珠利组外周血T淋巴细胞的转化率显著高于对照组(P＜0.05).可见,饮水中添加25 mg/L和50 mg/L妥曲珠利对肉鸡免疫机能有一定促进作用.     

肉鸡腹水症与大肠杆菌并发症的诊治

2003年6月，宣州区金坝乡某养鸡场饲养的近5000羽肉鸡，从22日龄至33日龄。陆续发病。发病率达60％以上。死亡率达40％，病程约2～4d。发病后用青霉素、链霉素拌料，恩诺沙星饮水均无明显效果，经临诊与实验室检查，诊断为肉鸡腹水症与大肠杆菌合并症。     

肉鸡腹水症与大肠杆菌合并症的诊治

2003年6月．宣城市宣州区某养鸡场饲养的近5000羽肉鸡．从22日龄至33日龄陆续发病。发病率达60％以上．死亡率达40％．病程约2～4天。发病后用青霉素、链霉素拌料,恩诺沙星饮水均无明显疗效．经临床诊断与实验室检查,确诊为肉鸡腹水症与大肠杆菌合并症。     

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 -