温度和光照对阿维拉霉素稳定性的影响

试验旨在研究不同剂型阿维拉霉素的稳定性,为其生产、运输及贮存等提供科学依据。试验以高效液相色谱法(HPLC)测定阿维拉霉素相对含量及单组分相对含量,分别通过温度试验和光照试验探讨贮存过程中阿维拉霉素相对含量及单组分相对含量的变化规律,以评价其预混剂及原料药两种剂型的稳定性。温度试验和光照试验结果均显示阿维拉霉素预混剂及阿维拉霉素原料药对温度和光照敏感,光照的影响大于温度的影响;但相同条件下阿维拉霉素原料药较阿维拉霉素预混剂稳定,阿维拉霉素A组分较B组分稳定。结果表明阿维拉霉素在运输及贮存时需确保避光,其贮存温度应低于20 ℃,以保证产品质量,提高稳定性。     

鸡源A型产气荚膜梭菌致病性及药物疗效分析

本研究旨在调查规模化养鸡场内鸡源产气荚膜梭菌（Clostridium perfringens，CP）的致病性和耐药性，并评价阿维拉霉素和磷酸泰乐菌素预防CP感染鸡群发生坏死性肠炎（necrotizing enteritis，NE）的效果，为鸡NE的防治提供指导。在河北、山西两地选择有CP引起NE发病史的规模化养鸡场，随机采集新鲜粪便，分离CP，并通过多重PCR测定其毒素型。选定3个不同养殖场分离到的A型CP，以10⁹CFU·只^-1的剂量，连续5 d经灌胃的方式感染14日龄SPF鸡，观察肠道病变和NE发生情况，评价分离菌株的致病力。使用微量肉汤稀释法测定分离到的CP对阿维拉霉素、林可霉素和磷酸泰乐菌素的最小抑菌浓度（minimal inhibitory concentration，MIC）。根据MIC结果，选择药物敏感性较好的两种药物对因CP引起NE发病的鸡群中未出现临床症状的鸡进行预防试验，观察精神食欲、腹泻症状、肠道病变情况，统计CP检出率和NE发生率，评价两种药物预防效果。结果显示：自753份鸡粪便样品分离到91株CP，且毒素型全部为A型。攻毒试验结果显示：A、B、C组攻毒组NE病变发生率均显著高于未攻毒组D组（P<0.05），攻毒组肠道病变评分均显著高于未攻毒组（P<0.05）。与未攻毒组相比，攻毒组出现明显的腹泻症状和肠道病变，差异显著（P<0.05），3株CP都可以引起鸡NE。MIC结果表明：阿维拉霉素、林可霉素和磷酸泰乐菌素的MIC范围分别是0.25～4、0.125～128和0.25～32 μg·mL^-1。药物疗效试验结果表明：通过拌料连续21 d给予阿维拉霉素预混剂，给药期间及停药后1周可保护鸡群，防止出现NE症状或防止病变恶化，显著降低NE发生率、NE病变评分以及CP检出率（P<0.05）。通过拌料连续7 d给予磷酸泰乐菌素预混剂，效果与阿维拉霉素预混剂相当，但停药14 d后，6只鸡（6/11）又出现NE症状。目前，河北、山西省部分规模化鸡养殖场内流行的CP多为A型，并且可以引起NE，同时，A型CP对阿维拉霉素和磷酸泰乐菌素仍较敏感，其预混剂用于发病鸡群的预防效果较好。     

Factors affecting storage stability of various commercial phytase sources

A 360-d study was performed to evaluate the effects of different environmental conditions on storage stability of exogenous phytases. Coated and uncoated products from 3 phytase sources [Ronozyme P (DSM Nutritional Products, Basel, Switzerland), OptiPhos (Phytex LLC, Sheridan, IN), and Phyzyme (Danisco Animal Nutrition, Marlborough, UK)] were stored as pure forms, in a vitamin premix, or in a vitamin and trace mineral (VTM) premix. Pure products were stored at -18, 5, 23, and 37°C (75% humidity). Premixes were stored at 23 and 37°C. Sampling was performed on d 0, 30, 60, 90, 120, 180, 270, and 360. Sampling of the pure products stored at -18 (lack of sample) and 5°C (because of mold growth) was discontinued after d 120. Stability was reported as the residual phytase activity (% of initial) at each sampling point. For the stability of the pure forms, all interactive and main effects of the phytase product, coating, time, and storage temperature were significant (P < 0.01), except for the time × coating interaction. When stored at 23°C or less, pure phytases retained at least 91, 85, 78, and 71% of their initial phytase activity at 30, 60, 90, and 120 d of storage, respectively. However, storing pure products at 37°C reduced (P < 0.01) phytase stability, with OptiPhos retaining the most (P < 0.01) activity. Coating mitigated (P < 0.01) the negative effects of high storage temperature for Ronozyme and OptiPhos (from d 90 onward), but not for Phyzyme. For the stability of phytase in different forms of storage, all interactive and main effects of phytase product, form, coating, time, and temperature of storage were significant (P < 0.01). When stored at room temperature (23°C), retained phytase activities for most the phytase sources were more than 85, 73, and 60% of the initial activity up to 180 d when stored as pure products, vitamin premixes, or VTM premixes, respectively. When stored at 37°C, pure phytase products had greater (P < 0.01) retention of initial phytase activity than when phytases were mixed with the vitamin or VTM premixes. Coated phytases stored in any form had greater (P < 0.01) activity retention than the uncoated phytases at all sampling periods. Results indicate that storage stability of commercially available phytases is affected by duration of storage, temperature, product form, coating, and phytase source. Pure products held at 23°C or less were the most stable. In premixes, longer storage times and higher temperatures reduced phytase activity, but coating mitigated some of these negative effects.     

薄层层析－紫外分光光度法测定预混剂中的恩拉霉素

试验旨在建立薄层层析－紫外分光光度法测定预混剂中恩拉霉素的方法。使用硅胶GF254薄层板为固定相,正丁醇∶冰醋酸∶水(2∶1∶1)为展开剂,在紫外光灯(254 nm)下定位,样品中的恩拉霉素得到较好分离。在271 nm波长处对不同含量的恩拉霉素标品进行紫外检测,结果表明,恩拉霉素点样量在20~166 μg范围内与吸光度呈现良好的线性关系(r=0.9989),平均回收率为99.85%,RSD值为3.1%(n=9)。此法所测定的结果与高效液相色谱(HPLC)法所测定的结果基本一致。该方法简单、快捷、准确、分析量大,适用于预混剂中恩拉霉素的定量分析。     

The effect of avilamycin in the control of stress-induced post-weaning diarrhoea in piglets

Avilamycin, an oligosaccharide antibiotic with growth-promoting properties in pigs, has proved to be effective in controlling stress-induced post-weaning diarrhoea in piglets, caused mainly by Escherichia coli. The present study includes two trials, in which 400 newly-weaned piglets were used (200/trial). The following five different treatments were tested; 0, 40 and 80 p.p.m. avilamycin, 50 p.p.m. olaquindox and 100 p.p.m. apramycin. In each trial there were four pens (each with five females and five males) per treatment. Avilamycin when given at 80 p.p.m. reduced average daily diarrhoea score (ADDS) and mortality, and improved liveweight gain and feed conversion ratio (FCR), compared with the untreated controls, the 40 p.p.m. avilamycin and the 50 p.p.m. olaquindox (P less than 0.05) treatments. The overall performance of 40 p.p.m. avilamycin and 50 p.p.m. olaquindox was similar. The results indicate that avilamycin at the dose level of 80 p.p.m. in the starter feed can control post-weaning diarrhoea of piglets and prevent loss of productivity. Nevertheless, the antibiotic apramycin, whose spectrum of activity is mainly against the Gram-negative bacteria, given at the therapeutic level of 100 p.p.m., was more effective than any other experimental treatment (P less than 0.05), except for ADDS and FCR which were not significantly different from that of avilamycin 80 p.p.m.     

那西肽预混剂组分HPLC检测方法的建立

为了建立那西肽预混剂组分测定的高效液相检查法,采用十八烷基键合硅胶为填充剂,以0.025%磷酸水溶液-乙腈(50:50)为流动相,检测波长为241 nm,并以该色谱条件对来自7个厂家的14批不同规格的那西肽预混剂进行了测定。综合结果给出组分的建议限度为:那西肽组分A的峰面积不得少于那西肽组分A与组分B峰面积之和的88.0%。该方法具有专属性强、耐用性好、操作简便等优点。     

不同铜源及贮存温度对仔猪复合预混合饲料中VA稳定性的影响研究

旨在研究超稳硫酸铜和碱式氯化铜作为铜源,对仔猪复合预混合饲料中VA稳定性的影响,并考查不同贮存温度对仔猪复合预混合饲料中VA稳定性的影响。采用单因子试验设计方法,设2个处理组,即超稳硫酸铜组和碱式氯化铜组。将各组配制好的试验样品平均分为9份,其中,3份置于常温环境,3份置于高温环境,3份置于低温环境。从第0天开始,每隔8 d检测1次所有样品中的VA含量,共检测32 d,计算不同贮存时间仔猪复合预混合饲料中的VA损失率。结果表明：在常温、高温和低温贮存环境中,随着贮存时间的延长,超稳硫酸铜组和碱式氯化铜组的VA损失率均呈升高趋势,并且在各检测时间点,超稳硫酸铜组的VA损失率均极显著低于碱式氯化铜组（P<0.01）;在饲料中铜源相同的情况下,贮存环境温度越高,VA损失率越高;贮存温度对仔猪复合预混合饲料中VA损失率的影响高于铜源对其的影响。综上提示,超稳硫酸铜可降低仔猪复合预混合饲料中VA的损失率,其作用显著优于碱式氯化铜,并且温度对VA稳定性的影响远超铜源对其的影响。     

诱食剂对育肥猪生产性能的影响

本试验旨在研究含有诱食剂的预混料对育肥猪生产性能的影响。试验选择60 kg左右的杜×大×长育肥猪108头,随机平均分到试验组和对照组中。试验组使用含有诱食剂的预混料,对照组使用不含有诱食剂的预混料。试验结果显示,添加含有诱食剂的预混料能够显著提高育肥猪的日增重15.4%(P<0.05),采食量极显著提高了15.8%(P<0.01),料肉比提高了0.1%,但差异不显著(P＞0.05),收入提高了15.3%。试验结果表明,使用含有诱食剂的预混料饲喂育肥猪,可以取得较为满意的经济效益。     

安徽省六安市猪预混料市场营销现状调查和分析

为了解安徽省六安市猪预混料市场营销现状,并为生猪养殖户科学选择预混料以及预混料生产企业制定销售策略提供参考,通过电话调查和走访的方式,对该市生猪养殖场的猪预混料使用情况进行了调查。结果表明：随着猪场养殖年限的增加会提高预混料的使用率;对于不同养殖模式的生猪养殖场,以养殖育肥猪为主的猪场更愿意使用预混料;年出栏育肥猪数量的增加会提高预混料的使用率;合理的价格、稳定的质量、及时的供货以及优惠政策的制订,均有利于维持养殖户对预混料产品的忠诚度。根据调查结果,提出以下建议：预混料厂家应以兽药饲料经销商作为主要分销渠道,将以出售育肥猪为主业且规模较大、养殖时间较长的猪场列为重点目标客户,加强售后服务,同时配合灵活的销售政策,培育忠诚的客户群,不断提高产品的市场竞争力;猪场采购预混料时要选择品牌形象好、价格合理、质量稳定、服务良好的产品。     

反刍动物饲料产品和动物源性饲料产品中牛羊源成分检测

[目的]检测反刍动物饲料和动物源性饲料中牛羊源成分。[方法]利用实时荧光定量PCR技术对反刍动物饲料产品（预混料、精料补充料、全价配合料等）和动物源性饲料产品（鱼粉、禽肉粉、猪肉粉、羽毛粉等）共计131批样品进行了牛羊源成分检测。[结果]所有样品中均未检出牛羊源性成分。[结论]该次抽检的反刍动物饲料产品和动物源性饲料产品中暂无牛羊源成分污染,但仍应加强对反刍动物饲料和动物源性饲料中牛羊源成分的监测。     

Tilmicosin enteric granules and premix to pigs: Antimicrobial susceptibility testing and comparative pharmacokinetics

The purpose of this study was to compare the pharmacokinetics and relative bioavailability of tilmicosin enteric granules and premix after oral administration at a dose of 40 mg/kg in pigs. Three kinds of different respiratory pathogens were selected for determination of minimal inhibitory concentration (MIC) to tilmicosin. Eight healthy pigs were assigned to a two‐period, randomized crossover design. A modified rapid, sensitive HPLC method was used for determining the concentrations of tilmicosin in plasma. Pharmacokinetic parameters were calculated by using WinNonlin 5.2 software. The MIC₉₀ of tilmicosin against Haemophilus parasuis, Actinbacillus pleuropneumoniae, and Pasteurella multocida were all 8 μg/ml. These results indicated that these common pig respiratory bacteria are sensitive to tilmicosin. The main parameters of time to reach maximum plasma concentration (T_max), elimination half‐life (t_1/2β), mean residence time (MRT), and apparent volume of distribution (V_F) were 2.03 ± 0.37 hr, 29.31 ± 5.56 hr, 25.22 ± 2.57 hr, 4.06 ± 1.04 L/kg, and 3.05 ± 0.08 hr, 17.06 ± 1.77 hr, 15.55 ± 1.37 hr, 2.95 ± 0.62 L/kg after the orally administrated tilmicosin enteric granules and premix. The relative bioavailability of tilmicosin enteric granules to premix was 114.97 ± 7.19%, according to the AUC_0‐t values. These results demonstrated that tilmicosin enteric granules produced faster tilmicosin absorption, slower elimination, larger tissue distribution, and higher bioavailability compared to the tilmicosin premix. The present study results manifest that tilmicosin enteric granules can be used as a therapeutic alternative to premix in clinical treatment.     

Pharmacokinetics of Curcumin Solid Dispersion in Piglets

A method for the detection of curcumin in pig plasma by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was established firstly and the pharmacokinetics of curcumin solid dispersion and curcumin premix in piglets were studied. Sixteen healthy piglets (Yorkshire×Changbai), seven-week aged, half male and half female, were randomly divided into two groups receiving curcumin solid dispersant and curcumin premix orally at the dose of 100 mg·kg^-1, respectively. Then plasma samples were collected at different time points, and the blood concentration of curcumin was determined by HPLC-MS/MS. The WinNonlin 5.2.1 software was used to analyze and calculate the pharmacokinetic parameters. The pharmacokinetic parameters of curcumin solid dispersion and curcumin premix were as follows: the area under the curve (AUC) was (104.53±38.67) and (37.82±11.48) h·ng·mL^-1, time to peak concentration (T_max) was (3.25±0.38) and (2.31±0.37) h, peak concentration (C_max) was (26.65±9.65) and (9.55±2.75) ng·mL^-1, respectively, elimination half-life time (t_1/2β) was (3.55±2.17) and (6.93±0.86) h, mean residence time (MRT) was (5.23±0.53) and (4.26±0.47) h. The statistical analysis showed significant differentce (P<0.01) between curcumin solid dispersion and premix in parameters, the T_max of curcumin solid dispersion was delayed significantly, the C_max was increased obviously and the AUC was improved after the piglets were given curcumin solid dispersion. Compared with curcumin premix, the relative bioavailability of curcumin solid dispersion was 280.39%. The results showed that curcumin solid dispersion could improve the dissolution and absorption of curcumin in the intestinal tract and improve the relative bioavailability of curcumin, which provided a scientific basis for the development and clinical application of curcumin solid dispersions in the future.     

姜黄素固体分散体在猪体内的比较药动学研究

本研究首次建立了测定猪血浆中姜黄素的高效液相色谱串联质谱法（HPLC-MS/MS），比较了在内服给药途径下，姜黄素固体分散体和姜黄素预混剂在仔猪体内的药动学特征。选用16头7周龄左右健康二元杂交猪（约克夏×长白），公母各半，随机分为2组，每组8头，按100 mg·kg^-1（以姜黄素计）分别灌服姜黄素固体分散剂和姜黄素预混剂，不同时间点采集血浆样品，经提取、净化后采用HPLC-MS/MS测定血浆中姜黄素的药物浓度，使用WinNonlin 5.2.1软件非房室模型计算、分析姜黄素在猪体内的药动学参数。结果显示，仔猪灌服姜黄素固体分散体和姜黄素预混剂后的药时曲线下面积（AUC）分别为（104.53±38.67）和（37.82±11.48）h·ng·mL^-1；达峰时间（T_max）分别为（3.25±0.38）和（2.31±0.37）h；峰浓度（C_max）分别为（26.65±9.65）和（9.55±2.75）ng·mL^-1；消除半衰期（t_1/2β）分别为（3.55±2.17）和（6.93±0.86）h；平均驻留时间（MRT）分别为（5.23±0.53）和（4.26±0.47）h，统计分析表明，与预混剂相比，仔猪灌服姜黄素固体分散体后，主要药动学参数差异显著（P<0.01），T_max明显延迟，C_max显著提高，AUC明显增大，姜黄素固体分散体的相对生物利用度为280.39%。结果表明，姜黄素固体分散体可改善姜黄素在肠道的吸收，提高姜黄素的生物利用度，为今后姜黄素固体分散体的开发和临床应用提供科学依据。     

液相色谱-串联质谱法检测猪血浆中除虫脲的方法学研究

【目的】考察口服灭蝇蛆药除虫脲（diflubenzuron，DFB）预混剂灌服给药后，在猪体内的药代动力学特征，建立猪血浆中除虫脲浓度的液相色谱-串联质谱（LC-MS/MS）检测方法。【方法】以除虫脲-¹³C₆（DFB-¹³C₆）为内标，血浆样品经甲醇沉淀蛋白，离心后取上清液减压浓缩至干，甲醇-水（1∶1）复溶后进行分析。色谱柱为ZORBAX Eclipse Plus C18柱；流动相为甲醇-0.1%甲酸水（含5 mmol/L甲酸铵），进行梯度洗脱；流速为0.4 mL/min；柱温为35 ℃；进样量为10 μL。电喷雾离子源，正离子模式，多离子反应监测模式检测，DFB及内标的定量离子对分别为m/z 311.1→158.1和m/z 317.1→158.1。对色谱和质谱条件优化后，考察该方法的专属性、定量下限、基质效应、线性范围、准确度、精密度和样品稳定性等。【结果】所建立的方法灵敏度高，检测限为0.5 ng/mL，定量限为1 ng/mL；基质效应对样品的检测影响较小；标准溶液在1~1 000 ng/mL的浓度范围内，线性关系良好（R²≥0.998）；在定量下限1 ng/mL及低（2 ng/mL）、中（100 ng/mL）、高浓度（800 ng/mL）的添加水平下，平均准确度在97.78%~115.06%之间，批内、批间变异系数均<10%，符合方法学要求。在考察的条件下，标准溶液、空白血浆加标样品及处理后的样品，稳定性良好；但应避免样品的反复冻融。【结论】建立的LC-MS/MS检测方法简便、专属性强、灵敏度高、准确可靠，可用于猪血浆中除虫脲浓度的检测，进而应用于除虫脲预混剂在猪体内的药代动力学研究。     

不同温度对紫罗勒叶片芳香物质成分及含量的影响

不同温度处理盆栽紫罗勒(Ocimum basilicum‘Purple Ruffles’)植株后,通过顶空固相微萃取自动进样(SPME)结合气相色谱–质谱联用(GC–MS)的技术分析了紫罗勒叶片芳香物质的成分及相对含量。结果表明,各温度处理下紫罗勒叶片共检出55种化合物,其中芳樟醇是紫罗勒叶片的主要芳香成分。但不同温度处理后,紫罗勒叶片芳香物质的成分及相对含量有所不同。综合考虑,温度为15℃(昼/夜,20℃/10℃)是紫罗勒芳香成分提取较为理想的温度条件。     

The nutritive effect of avilamycin in swine breeding and fattening

During a total period of treatment of 141 days, divided into starter grower and fattening period, the efficacy of avilamycin in a dosage of 80 mg/kg (starter grower) and 20 mg/kg (fattening) rsp. 40 mg/kg and 20 mg/kg was investigated in comparison with a negative control group and the additive tylosin. Growth was partially significantly increased by avilamycin at a dosage of 40 mg/kg/20 mg/kg compared to the control. Average daily weight gains of the starter grower period were improved for about 12%, feed conversion ratio for about 14%. In spite of a clear decrease in the efficacy of the additive during fattening period, a superiority of the avilamycin-group over the control- and the tylosin-group could be saved when avilamycin was added till the end of the fattening period. So addition of avilamycin in a dosage of 40 mg/kg during starter grower and 20 mg/kg during fattening period can be recommended.     

预混料中微量元素、水分和pH值对维生素A和烟酰胺稳定性的影响

为了研究水分、pH值及微量元素对预混料中维生素A和烟酰胺稳定性的影响,试验采用均匀试验设计,在近似于生产的高温贮藏条件(37℃)下,在第0,15,30,45,60天取样测定4%仔猪预混料中的维生素A和烟酰胺损失率及水分、pH值、过氧化值、总抗氧化能力的变化。结果表明:预混料中添加微量元素导致了维生素A和烟酰胺的额外损失,随微量元素添加量的增加,维生素A和烟酰胺的损失率也显著增加(P<0.05);硫酸根和水分显著或极显著影响维生素A损失量和过氧化值(P<0.05或P<0.01);在贮藏阶段非微量元素因素(甲酸根、碱式碳酸根、硫酸根、水分、pH值)与维生素稳定性在前15 d呈显著相关(P<0.05),15 d后呈极显著相关(P<0.01)。     

ED-XRF法快速测定虾预混合饲料中钙、磷含量

虾预混合饲料中钙（Ca）、磷（P）含量直接影响虾的生长、发育和健康状况。传统的化学分析方法需要对虾预混合饲料进行复杂的预处理,取得测试结果需要花费数小时。采用一种简单、快捷的分析方法——能量色散X射线荧光光谱法（ED-XRF）,对虾预混合饲料进行粉碎、压片和测试,在数分钟内获得了样品的测试结果。ED-XRF法对Ca、P的检出限分别为43 mg/kg和163 mg/kg,定量限分别为142 mg/kg和544 mg/kg。对虾预混合饲料3^#样本连续测试6次,Ca、P的连续测定数据的极差分别为0.159%和0.013%,分别小于推荐性国家标准中Ca、P含量检测的重复性临界差CrR₉₅（6）0.239%和0.031%,表明ED-XRF法满足推荐性国家标准对饲料中Ca、P含量测定的要求。通过对10个已定值的虾预混合饲料样品进行Ca、P含量测定,ED-XRF法的测定值与推荐性国家标准中相关方法测定值的相对差值不大于4.55%。综上表明,ED-XRF法具有较高的精密度和准确度,可用于虾预混合饲料生产企业对Ca、P元素添加量的监控。     

新型预混料对奶牛酒精阳性乳防治作用的研究

为了验证针对酒精阳性乳（alcohol positive milk,AMP）发病机理制作的新型预混料对奶牛酒精阳性乳的防治效果,本研究设计了试验1和试验2：在试验1中,根据泌乳天数、酒精阳性乳程度,采用完全随机区组方法将100头荷斯坦泌乳后期牛分为对照组、低剂量（LDG）、中剂量（MDG）和高剂量组（HDG）,每组5个重复,每个重复5头牛,各组在日粮中依次添加0、50、100和150 g/（头·d）新型预混料,试验期26 d,3 d为1个采样周期;在试验2中,按照试验1的分组方法,将370头荷斯坦泌乳后期奶牛分为对照组和试验组,每组185头,在日粮中依次添加0和100 g/（头·d）新型预混料,试验期35 d,每5 d为1个采样周期。将奶样与等量的75%中性酒精混合,通过观察奶样状态判断酒精阳性乳发生程度。试验1结果表明,与对照组相比,在日粮中添加50 g/（头·d）新型预混料对酒精阳性乳的发生率有一定的影响（P>0.05）;日粮中添加100和150 g/（头·d）新型预混料能显著降低酒精阳性乳发生率（P<0.05）,尤其对降低强阳性酒精阳性乳发生率效果极显著（P<0.01）,但两组之间差异不显著（P>0.05）。试验2结果表明,到试验结束时,日粮中添加100 g/（头·d）新型预混料可使酒精阳性乳总发生率降低75.73%,强阳性酒精阳性乳发生率降低90.82%。以上结果表明,新型预混料能有效防治奶牛酒精阳性乳的发生,且日粮中新型预混料的最佳添加量是100 g/（头·d）。     

氟苯尼考预混剂对Wistar大鼠的口服急性毒性试验研究

本研究旨在评估氟苯尼考预混剂对Wistar大鼠的口服急性毒性,使用OECD修订的改良上下法（UDP）测定半数致死量（LD₅₀）,通过体重、脏器系数、血液学、临床化学检查及组织病理学检查确定在急性暴露下氟苯尼考预混剂对Wistar大鼠的生物系统和主要器官的不良影响。根据氟苯尼考的LD₅₀>5 000 mg/kg,选择上下法的限度试验,使用固定数量（5只）的动物,给药剂量为2 000 mg/kg,连续观察14 d,记录毒性反应及死亡情况,并由AOT425StatPgm程序计算得到LD₅₀,另外用3只大鼠给予相同剂量的生理盐水作为对照。试验结果显示,5只大鼠均未死亡,LD₅₀>2 000 mg/kg;试验期间,给药组未表现出可见的毒性反应迹象;与对照组相比,给药组的血液学参数无显著性变化;在临床化学检查中,给药组的谷丙转氨酶（ALT）水平变化显著高于对照组（P<0.05）,提示药物制剂对肝脏存在毒性损伤;剖检观察中无明显的眼观变化,组织病理学检查结果显示,给药组对主要器官心脏、肝脏、脾脏、肺脏、肾脏及十二指肠均无毒性损伤作用,暂无法确定其毒性靶器官。结果表明,氟苯尼考预混剂在安全剂量范围内使用是安全可靠的,更多的毒性信息仍需进行长期毒性试验来确定。