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1.
乙酰甲胺磷对家蚕3龄起蚕的急性食下毒性(LC50)为41.80 mg/L,中等毒性;在常规使用浓度下对家蚕无熏蒸毒性。用30%乙酰甲胺磷EC 300倍、600倍和1200倍稀释液对桑树进行局部喷叶或根灌处理,喷药桑叶对3龄起蚕无中毒死亡的间隔时间为30 d、25 d和25 d,在桑叶上的残毒期中等偏长;未直接喷药的桑叶可使家蚕出现不同程度的中毒死亡,表明乙酰甲胺磷可通过桑叶、桑根内吸传导至上部桑叶。结果表明,乙酰甲胺磷用于防治桑园害虫应注意掌握安全间隔时间。  相似文献   

2.
为评价埃谱利诺菌素浇泼剂对绵羊消化道线虫驱虫效力,选择1.5岁自然感染消化道线虫的绵羊100只,随机分为5组,每组20只,1~3组为埃谱利诺菌素浇泼剂0.4、0.5和0.6mg/kg.b w组,沿背部皮肤中线浇注给药,4组为埃谱利诺菌素注射剂药物对照组,按0.2mg/kg剂量颈部皮下注射,5组为阳性对照组,不给药;采用粪便虫卵检查法评价驱虫效果。结果:给药后7、14d检查,0.5mg/kg剂量对消化道线虫虫卵转阴率分别为90.0%、95.0%,减少率分别为97.0%和99.3%; 0.6mg/kg剂量给药后7、14d检查,对消化道线虫虫卵转阴率、减少率均达100.0%; 0.4mg/kg剂量对消化道线虫虫卵的转阴率、减少率均低于0.5、0.6mg/kg剂量组。对照药物埃谱利诺菌素注射剂0.2mg/kg剂量组对消化道线虫的驱虫效果略高于埃谱利诺菌素浇泼剂0.5mg/kg剂量组;埃谱利诺菌浇泼剂3个剂量组试验绵羊未见异常反应。试验证明埃谱利诺菌浇泼剂0.4、0.5、0.6mg/kg体重剂量驱除绵羊消化道线虫安全有效,其中0.5、0.6mg/kg剂量高效安全低残留,推荐剂量以0.5mg/kg为宜。  相似文献   

3.
为建立盐酸莱克多巴胺(RAC)在鸡血清和组织中残留的检测方法,探究其消除规律,本研究以1mg/kg、3mg/kg和9mg/kg的添加剂量将R AC混入饲料,连续饲喂21d,在用药后第1、3、7、14、21d和休药后1、3、7d,分别采集实验组和对照组鸡血液、肌肉、肝脏和胃组织样品,酶联免疫吸附试验(ELISA)检测各样品RAC含量。实验结果为实验组鸡血清中RAC残留量在第7d达到高峰,第7~14天持续下降,第21d出现第2个残留高峰;肌肉中残留量在第7d达到高峰,后逐渐降低;肝脏中比较容易达到残留高峰,第21天后,RAC残留量迅速下降;胃中残留量第14d达到高峰。用ELISA对组织和血清中残留RAC的检测发现,RAC残留浓度基本遵循肝脏胃肌肉血清,休药7d后为胃肝脏肌肉血清。  相似文献   

4.
65%毒死蜱乳油是防治桑螟等害虫的桑树专用有机磷杀虫剂。于春、秋2季分别以325 mg/L、650 mg/L毒死蜱药液1次或2次喷施桑树后,采用气相色谱检测技术定量分析药物在桑叶和桑园土壤中的残留动态变化,建立药物降解曲线方程,用于预测施药后能确保蚕作安全的间隔时间。检测桑叶中药物的降解过程:施药后7 d内药物降解速度较快,以施药后1 d内最快,期间不同浓度药液及施药次数处理组间样品检测值差异较大;施药7 d后,样品检测值趋于稳定,且2次施药处理的药剂残留始终高于1次施药处理,而施药浓度与药剂残留量的关系不大,多次施药后药物残留有累积作用。检测土壤中药物的残留量低于同期以相同浓度药液处理后在桑叶中的残留量,1次施药的残留量低于2次施药的残留量,但秋季施药14 d后,药物在土壤中的降解则更加缓慢。采用650 mg/L毒死蜱药液喷施1次和2次后的检测数据,建立了药物在桑叶及桑园土壤中的降解曲线方程,用于测算毒死蜱药液喷施桑树后桑叶中药物残留量0.5 mg/kg时的家蚕安全饲养间隔期:春季1次施药为16~18 d,2次施药为22 d;秋季1次施药为25 d,2次施药为30 d。  相似文献   

5.
目的 通过唑虫酰胺在柑橘及土壤中开展的两年三地的残留试验并进行风险评估,为制定唑虫酰胺在柑橘上的最大残留限量值提供数据支撑。方法 根据农药残留试验准则和标准操作规程开展田间试验,样品前处理后通过液相色谱-串联质谱测定得到试验数据,再进行风险评估。结果 唑虫酰胺在柑橘和土壤0.010~1.5 mg/kg的添加水平中,平均回收率达到90.6%~107.4%,相对标准偏差为1.5%~9.0%,定量限为0.010 mg/kg。两年三地唑虫酰胺在柑橘上的半衰期为17.3~34.7 d,土壤中的半衰期为5.8~34.7 d,末次施药后间隔21 d采集柑橘和土壤样品测定唑虫酰胺残留量均低于美国规定的最大残留限量值,不存在膳食摄入风险和急性膳食风险。结论 按照美国规定的最大残留限量值(MRL)1.5 mg/kg,间隔21 d采集的柑橘是相对安全的,唑虫酰胺的残留风险较低。  相似文献   

6.
进行了两个实验:实验一观察药物对鸡ND疫苗初次免疫的影响,结果显示7日龄高母源抗体(9.36log2)雏鸡免疫ND活疫苗前用药,10mg/kg西咪替丁用药鸡免疫后7~14d、100mg/kg西咪替丁用药鸡免疫后7~28d,抗体滴度明显升高;10mg/kg左旋咪唑用药鸡免疫后7~21d,抗体滴度与未用药对照组无明显差别,但28d抗体滴度明显高于未用药对照组。免疫后用药,10mg/kg西咪替丁用药后7d,抗体滴度明显高于空白对照组;用药后14d,各用药组抗体滴度与空白对照组无明显差别;用药后21d,10、100mg/kg西咪替丁和10mg/kg左旋咪唑用药鸡抗体滴度均明显高于空白对照组。实验二观察药物对ND疫苗二次免疫的影响,结果显示10、100mg/kg西咪替丁用药ND疫苗二次免疫后7~28d,鸡血清抗NDV抗体滴度明显高于未用药对照组。10mg/kg左旋咪唑用药组,疫苗二次免疫后7~28d,抗体滴度也明显升高。  相似文献   

7.
溴虫腈在桑叶中的残留毒性与降解动态检测   总被引:5,自引:2,他引:3  
为了保证桑园喷施杀虫剂溴虫腈后的养蚕用叶安全,采用食下毒叶法测定了溴虫腈对家蚕的残留毒性,用气相色谱法检测了喷药后不同时间桑叶中的药剂残留动态变化。结果表明:桑园内分别喷施250、200、150、100、50mg/L溴虫腈,检测到药剂在桑叶的残留毒性期分别为>5 d、>5 d、3 d、1 d和0 d;200 mg/L溴虫腈在桑叶中的降解动态方程为C=95.335e-0.159 9t(R2=0.906 8),半衰期为4.33 d,此检测方法的最低检出药剂残留质量比为3.97×10-4mg/kg;桑树盛产期喷洒100 mg/L溴虫腈后2 h、1 d、3 d、5 d、7 d、14 d、21 d和28 d,药剂在桑叶中的残留量分别为40.969、39.814、20.226、18.726、9.975、5.522、2.774和0.026 mg/kg;200 mg/L和100 mg/L溴虫腈2次喷施处理桑叶21 d后的最终残留量分别为12.958、4.242 mg/kg。10%溴虫腈悬浮剂用于桑树害虫或害螨防治的建议使用浓度为100 mg/L,采叶安全间隔期为施药后5 d。  相似文献   

8.
西咪替丁对鸡新城疫疫苗免疫效果的影响   总被引:4,自引:0,他引:4  
进行了两个实验:实验一观察药物对鸡ND疫苗初次免疫的影响,结果显示7日龄高母源抗体(9.36log2)雏鸡免疫ND活疫苗前用药,10mg/kg西咪替丁用药鸡免疫后7-14d,100mg/kg西咪替丁用药鸡免疫后7-28d,抗体滴度明显升高;10mg/kg左旋咪唑用药鸡免疫后7-21d,抗体滴度与未用药对照组无明显差别,但28d抗体滴度明显高于未用药对照组。免疫后用药,10mg/kg西咪替丁用药后7d,抗体滴度明显高于空白对照组;用药后14d,各用药组抗体滴度与空白对照组无明显差别;用药后21d,10,100mg/kg西咪替丁和10mg/kg左旋咪唑用药鸡抗体滴度均明显高于空白对照组。实验二观察药物对ND疫苗二次免疫的影响,结果显示10,100mg/kg西咪替丁用药ND疫苗二次免疫后7-28d,鸡血清抗NDV抗体滴度明显高于未用药对照组。10mg/kg左旋咪唑用药组,疫苗二次免疫后7-28d,抗体滴度也明显升高。  相似文献   

9.
罗兰  袁忠林  孙娟 《草业学报》2017,26(1):160-167
为评价10%吡虫啉可湿性粉剂、10%氯氰菊酯乳油和48%毒死蜱乳油对苜蓿蚜虫和蓟马的防治效果和安全性,采用田间喷雾法和气相色谱法测定了3种杀虫剂对苜蓿蚜虫和蓟马的防治效果及其在春季紫花苜蓿中的残留消解动态和最终残留量。结果表明,吡虫啉、氯氰菊酯和毒死蜱在剂量分别为35.7 g a.i. (g有效成分)/hm2、75.0 g a.i./hm2和480.0 g a.i./hm2时,药后1~7 d对苜蓿蚜虫的防效为80.83%~94.78%、79.29%~87.80%和90.93%~98.90%;对苜蓿蓟马的防效为78.33%~95.57%、78.56%~91.67%和92.78%~100.00%;在紫花苜蓿中的半衰期分别为4.78,3.69和2.48 d。按推荐使用量施药,吡虫啉和毒死蜱药后7 d在苜蓿中的残留量均低于0.5 mg/kg,氯氰菊酯药后14 d在苜蓿中的残留量均低于0.5 mg/kg。参照我国和国际食品法典委员会(CAC)农药残留限量要求,拟建议吡虫啉、氯氰菊酯和毒死蜱在紫花苜蓿的最高残留限量(MRL)分别为0.5,1.0和0.5 mg/kg,安全间隔期分别为7,14和7 d。  相似文献   

10.
几种桑园常用杀虫剂对家蚕的残毒期试验   总被引:16,自引:3,他引:13  
设计桑虫清、辛硫磷、乙酰甲胺磷不同浓度的处理区 ,以喷药距收蚁日期的天数为处理水平 ,研究各处理对家蚕的残毒期。应用BASIC语言编程 ,对试验资料进行回归分析的结果是 :各处理间以幼虫期死蚕率差异最显著 ,喷药到收蚁的天数与死蚕率的相关关系曲线与指数函数型 (y =cebx)相吻合 ;喷药到收蚁的天数与蔟中死蚕率的相关关系 ,呈抛物线型 (y=a +bx +cx2 )。各处理间的茧质无显著差异。桑虫清的残毒期为 7~ 8d ,辛硫磷为9~ 10d ,乙酰甲胺磷为 15d以上。残毒期与药剂剂量呈正相关  相似文献   

11.
Introduced rodents have been eradicated from large numbers of offshore islands using toxic baits; however, toxic baits have been linked with negative impacts on non‐target species. The present study assessed the bait take of target (house mouse, Mus musculus) and non‐target (buff banded rail, Rallus philippensis) animals on Northwest and Heron Islands in the Great Barrier Reef. Three non‐toxic bait formulations (wax block, pellet and grain) were tested and each was applied at 1 kg ha?1 in six treatment grids. The tracks of animals visiting the baits were identified using 30 tracking stations per treatment grid. A tracking station consisted of a track‐board placed in the centre of a sand‐pad. Mean bait take differed significantly between the formulations: birds took more grain bait than wax block bait; mice took more wax block than grain bait. Both mice and birds were equally selective of pellet bait. Thus, the findings indicate that wax blocks are the most suitable formulation for future baiting programs to eradicate mice on these and other islands.  相似文献   

12.
1. Our objective was to evaluate the toxic effects of aflatoxin B1 (AFB1) and fumonisin B1 (FB1), administered singly or in combination to broilers. 2. Feeds were prepared with concentrations equal to 0, 50 and 200 microg AFB1/kg, and/or 0, 50 and 200 mg FB1/kg, and offered to broiler chicks from 8 to 41 d of age. The experimental design was totally randomised, in a 3 x 3 factorial arrangement with 9 treatments and 12 birds per treatment. Animals were vaccinated against Newcastle disease on d 14 of life and killed at 41 d. 3. Compared with controls, all mycotoxin-treated groups at 41 d had lower body weight and weight gain, and higher relative heart weight. The relative weight of the liver increased only in birds fed diets containing 200 mg FB1, singly or in combination with AFB1. 4. At 35 d, all groups receiving mycotoxin-treated rations had reduced geometrical mean antibody titres, with birds from groups fed combinations of AFB1 and FB1/kg having even lower values, when compared to the other groups. 5. Histological changes were observed only in liver from birds fed mycotoxin-contaminated rations, and in kidneys of birds fed the diet containing 200 microg AFB1 and 200 mg FB1/kg. Main alterations included vacuolar degeneration and cell proliferation of bile ducts in the liver, and hydropic degeneration in renal tubules in the kidneys. 6. We concluded that AFB1 and FB1 in combination have primarily additive effects on body weight, liver structure and immunological response of broilers at the concentrations used.  相似文献   

13.
In this study, ecological models, optimisation algorithms and threshold analysis were linked to develop oral-vaccination strategies against rabies in fox populations. It is important that such strategies are cost-efficient and resistant to environmental conditions which would lessen their success.The model validation shows that the ecological models used are suited to predict the proportion of tetracycline- (TC) marked foxes in the course of time. This figure indicates the proportion of foxes which had at least one contact to vaccine baits, and is based on the design of the vaccination strategy (i.e. the number and timing of vaccination campaigns and the number of baits used per square kilometre and campaign). The design of a vaccination strategy also determines the costs.It is the combination of ecological models and optimisation algorithms that helped us to design a vaccination strategy which is capable of achieving a continuous rate of >70% of TC-marked foxes within an analytical horizon of 3 years at low costs. Compared to the standard strategy (baseline comparator), the improved strategy incurs just over half of the cost while almost doubling the number of weeks during which the proportion of TC-marked foxes is >70%.In the improved strategy, June is recommended as the time for bait distribution. The standard strategy, however, avoids summer months (because high temperatures reduce the durability of the baits) which again leads to a reduction of the bait intake by the foxes. Using threshold analysis, we examined the effect of a reduced durability of the baits on the design of the improved vaccination strategy. We concluded that distribution of baits in June was optimal given that the durability of baits is above a threshold of 7 days.  相似文献   

14.
The aim of this study was to evaluate the efficacy of lyophilised C-strain vaccine in domestic pigs and wild boar after oral application. A new spherical bait form (diameter 3 cm) containing lyophilised vaccine virus and the recent vaccine baits were used for animal experiments. Four vaccination groups were established in experiment 1 (group 1: recent liquid bait vaccine; group 2: spherical baits containing one dose of the lyophilised vaccine; groups 3 (domestic pigs) and 4 (wild boar): spherical baits containing two doses of the lyophilised vaccine) and two groups in experiment 2 (group 1: recent liquid bait vaccine; group 2: spherical baits with two doses of the lyophilised vaccine). Challenge was carried out with the highly virulent virus strain "Alfort 187" (using 100 TCID50 in the first and 1.000 TCID50 in the second experiment). Our results showed that the animals vaccinated with lyophilised C-strain vaccine developed high neutralising antibody titres comparable to those obtained after vaccination with the recent bait vaccine. All pigs which picked up the baits remained healthy after challenge. Neither clinical symptoms nor viremia or virus shedding were observed after infection except in one pig (group 2, experiment 2) which had not consumed the vaccine bait. The surviving domestic pigs and wild boar were tested negative for CSFV and viral RNA at the end of the study. This result demonstrates that lyophilised vaccine may become an effective vaccine formulation for oral immunisation of wild boar against CSF in the near future.  相似文献   

15.
A field trial was conducted on a farm in Michigan with commercial turkeys naturally infected with Ascaridia dissimilis. The birds were treated at approximately 8 and 14 wk of age on a per-barn basis with fenbendazole (Safeguard) in the feed at 16 ppm for 6 d (1 barn), or with levamisole (Prohibit) in the water at 16 mg/kg of BW (2 barns). Six birds were obtained at random and sacrificed in each barn for worm burden determinations before treatments and again soon after treatments. Nematicidal efficacies for fenbendazole and levamisole were shown to be 99.3 to 99.9% and 54.6 to 85.8%, respectively. Despite the far greater reductions in worm burdens by fenbendazole as compared with levamisole, the burdens at the time of retreatment had equalized in all barns, illustrating the role of premunition regarding turkey ascaridiasis, and highlighting the overriding importance of reducing the challenge to provide long-term control of this parasitism.  相似文献   

16.
A study was conducted to evaluate the Met-sparing effects of the methyl donors, choline (CHO) and betaine (BET). Male broilers of a commercial strain were fed corn-soybean meal-based diets formulated to meet nutritional levels typical of top broiler producers. Diets were fortified with a complete vitamin premix devoid of CHO. In test diets, Met levels were as formulated, or less 0.05, 0.10, 0.15, or 0.20% Met. Within each Met level, diets received no supplemental CHO or BET or 1,000 mg of CHO/kg, 1,000 mg of BET/kg, or a combination of 500 mg each of CHO and BET/kg. This resulted in a 4 × 5 factorial arrangement with each of the 20 treatments fed to 4 pens of 60 birds for a 56-d feeding trial. Samples of birds were processed at 42, 49, and 56 d to determine parts yield and dressing percentage. Intestinal segments were evaluated for tensile strength at these same ages.The dietary Met level had no significant impact on BW at 14 or 56 d of age, but at 35, 42, and 49 d reduction of the Met content resulted in loss of BW. Feed conversion was not affected by the Met level at 14 d but was significantly affected by reducing the Met level at all other ages. Breast meat yield was reduced in a linear manner by reductions in Met supplementation. The CHO or BET supplementation had no apparent sparing effect on Met needs but did improve feed conversion at 35 and 42 d. There was a positive effect of CHO and BET on breast yield that was independent of Met levels; CHO was as effective as BET for this purpose. No effect of CHO or BET on intestinal strength was observed in the present study.  相似文献   

17.
OBJECTIVES: To develop an encapsulation method for delivery of vaccines to feral pigs, and quantify the effect of iophenoxic acid on captive feral pig blood iodine concentrations to assist in investigation of factors affecting vaccine uptake. DESIGN AND METHODS: Feral pigs were administered iophenoxic acid by oral gavage, and consumption was assessed for different encapsulation methods in baits. Blood iodine concentrations were monitored for eight days after consumption. The relationship between dose rate, time since dosing and blood iodine concentration was assessed for gavaged and baited captive feral pigs. Wild feral pigs were baited with PIGOUT baits containing 20 mg of encapsulated iophenoxic acid to simulate a vaccination program. Using knowledge from the pen studies, bait uptake and factors affecting bait uptake were investigated. RESULTS: Bait-delivered iophenoxic acid led to variable and inconsistent changes in blood iodine concentrations, in contrast to pigs receiving iophenoxic acid by gavage. This precluded accurate assessment of the quantity consumed, but still allowed a conservative determination of bait uptake. Iophenoxic acid in smaller capsules was consumed readily. Increasing baiting intensity appeared to increase bait uptake by wild feral pigs, and pigs of varying sexes, ages and weights appeared equally likely to consume baits. CONCLUSIONS: Encapsulated liquids can be delivered to feral pigs within baits, should the need to vaccinate feral pigs for fertility or disease management arise. High baiting intensities may be required.  相似文献   

18.
Bait disappearance can give valuable information for the assessment of oral vaccination campaigns of foxes against rabies. In this study, the spatial and temporal disappearance of three different vaccine baits under almost identical conditions was investigated. In the study area, 350 baits were placed at previously marked positions during two different periods; late autumn and early spring. The distribution of baits was in accordance with the method as recommended by the European Union; a density of 20 baits per km2 along flight lines 500m apart. Bait disappearance was checked 1, 3, 5 and 7 days after distribution. At least 80% of the baits had disappeared within one week after distribution. No difference in bait disappearance was observed between the two selected periods. However, a significant higher bait disappearance was observed in forested areas when compared to open agricultural areas. Furthermore, the differences in bait disappearance between the three type of baits tested were relatively small and not significant.  相似文献   

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