断奶仔猪料中金霉素与酶制剂的配伍研究

在日粮中添加亚治疗量的抗生素能改善畜禽的生产性能（Jukes，１９９０；张伟，１９９７）。由于诸如药物残留、长期使用引发耐药性等问题的日益严重，许多国家和组织，包括中国在内，相继实施了限制抗生素使用的规定（李美同等，１９９１；薛恒平，１９９６）。在为数不多的可用抗生素中，金霉素是配合饲料中常见的一种。饲用酶制剂的优越性已逐步被接受，研究表明酶制剂可有效地改善动物的生产性能，但由于饲用酶应用理论研究的滞后，迄今尚难找出成熟的复合酶的使用途径与作用方式（莫棣华，１９９７），却经常能见到饲用酶与抗生素同时…     

Comparative pharmacokinetics of chlortetracycline in milk-fed versus conventionally fed calves

Plasma and tissue concentration and pharmacokinetics of chlortetracycline (CTC) was determined in milk-fed and conventionally fed Holstein calves. A two-compartment open model was used after a single intravenous dose (11 mgn CTC/kg body weight). There were no significant differences between dietary treatments. The drug was rapidly distributed from plasma into the peripheral compartment but was slowly eliminated, with detectable concentration of CTC continuing for 72 h after dosing. A single-compartment model was used after a single oral dose (22 mg CTC/kg body weight). All but four of the kinetic parameters were significantly different for the two dietary treatments. Milk-fed calves had a larger area under the plasma level curve, a larger fraction of the dose absorbed, a smaller volume of distribution and a smaller overall body clearance rate. Estimated recovery of CTC in the urine of the milk-fed calves was greater, regardless of route of administration. The concentration of CTC in tissues following an oral dose was greatest in kidney, followed by liver, heart, skeletal muscle, spleen and brain. Tissue depletion of CTC closely paralleled the decline in plasma concentration.     

Disodium-fosfomycin pharmacokinetics and bioavailability in post weaning piglets

Disodium-fosfomycin pharmacokinetics has been studied in different species after oral, intravenous, intramuscular and subcutaneous administration. At present there are neither documented clinical experiences of the use of fosfomycin in pigs nor any published studies in weaning piglets, although it is a period of high incidence of infectious diseases. The pharmacokinetics and the bioavailability of sodium fosfomycin were studied in post weaning piglets after intravenous and intramuscular administration of 15 mg/kg of body weight. Plasma concentrations were measured by a high-performance liquid ms/ms. After IV administration the area under the fosfomycin concentration:time curve in plasma was AUC_(0–12) of 120.00 ± 23.12 μg h/ml and the volume of distribution (Vd) of 273.00 ± 40.70 ml/kg. The elimination was rapid with a plasma clearance of 131.50 ± 30.07 ml/kg/h and a T_1/2 of 1.54 ± 0.40 h. Peak serum concentration (C_max), T_max, AUC_(0–12) and bioavailability for the IM administration were 43.00 ± 4.10 μg/ml, 0.75 ± 0.00 h, 99.00 ± 0.70 μg h/ml and 85.5 ± 9.90% respectively. Different authors have determined a minimum inhibitory concentration (MIC₉₀) ranging from 0.25 μg/ml for Streptococcus sp. and 0.5 μg/ml for Escherichia coli. Considering the above, and according to the values of plasma concentration vs time profiles observed in this study, effective plasma concentrations of fosfomycin for sensitive bacteria can be obtained following IV and IM administration of 15 mg/kg in piglets.     

Gentamicin pharmacokinetics in newborn and 42-day-old male piglets

The pharmacokinetics of gentamicin was investigated in six newborn male piglets, aged from 4 to 12 h at the time of administration of the drug, and six 42-day-old castrated male piglets, that had been weaned for 2 weeks following a single intravenous bolus of 5 mg/kg. Gentamicin was measured in serum and in urine by a fluorescence polarization immunoassay. The serum concentrationtime data were best described by a three-compartment open model. A rapid initial distribution phase (± phase) was observed in every animal. The serum β half-life (t_1/2β) was significantly longer in the newborn piglets (mean ± SEM) (5.19 ± 0.30 h) than in the older group (3.50 ± 0.23 h) (P < 0.05). Mean residence time was similarly longer in younger piglets (6.62 ± 0.57 h) than in older animals (2.86 ± 0.11 h) (P < 0.05). The steady-state volume of distribution (V_ills was significantly larger for younger pigs (0.785 ± 0.036 L/kg) than in elder pigs (0.474 ± 0.029 L/kg) (P < 0.05). Urinary γ half-life (t_1/27u) was 72.66 ± 10.78 h in the newborn piglets and 69.20 ± 14.77 h in the 42-day-old animals. A urinary δ phase was observed in three of the 42-day-old piglets and gave a mean (t_1/2δu of 232.01 ± 14.55 h. Percentages of urinary recovery of the administered dose after 144 h were 94.18 ± 1.01 and 94.04 ± 1.12 in the newborn and 42-day-old animals, respectively. Serum gentamicin clearance was significantly lower in younger animals (0.121 ± 0.007 L/h±kg) than in the 42-day-old group (0.166 ± 0.010 L/h·kg). It is suggested that in the newborn piglets, the increase of V_d(ss) could be explained by a higher proportion of extracellular water while the lower clearance could be attributed to a reduced glomerular filtration capacity. Gentamicin dosage requirement in the newborn piglets would therefore have to be adjusted, in order to take into consideration the observed differences in the mean values of these latter pharmacokinetic parameters.     

二阶段早期断奶乳猪配合饲料的配制

所谓二阶段早期断奶乳猪配合饲料,是指将乳猪从出生到60日龄划分为从出生到断奶和断奶到60日龄2个阶段,根据乳猪在这2个阶段的发育特点和营养需要,分别为其配制不同的配合饲料,充分发挥乳猪生长潜能,降低饲料成本,使养猪户得到更大利润。如何配制符合我国养猪业情况的二阶段早期断奶乳猪配合饲料,我们认为应重视以下几个问题。1　配制早期断奶乳猪配合饲料前必须掌握以下3点11　尽早使乳猪适应固体饲料　配制哺乳期仔猪料的主要目的,是为了使乳猪尽早地适应固体饲料,为它们进入生长肥育阶段做准备。如果乳猪不能很快适应生长肥育阶段的各种…     

帕托珠利混悬液在仔猪体内的药代动力学及生物利用度研究

为研究帕托珠利混悬液在仔猪体内的药动学特征及生物利用度,采用平行实验设计方法,将16头 40 日龄健康仔猪随机分成两组,每组8头（公母各半）,分别进行单剂量静脉注射（6mg/kg bw）和单剂量口服给药（15mg/kg bw）,所有猪给药前禁食12h,给药2h后恢复正常饮食。给药后按预定的采血点采集血样,血浆中帕托珠利的含量采用经验证的 HPLC检测方法进行测定。实测血药浓度数据采用Graphad prism 8.0拟合药时曲线图,并用 Winnonlin5.2计算药动学参数。结果显示,单剂量静脉注射帕托珠利注射液后帕托珠利在仔猪体内主要药动学参数如下：平均消除半衰期（T1/2?）为136.98h,平均滞留时间（MRT）为165.92h,平均药时曲线下面积（AUC0-t）为1570.97 h?μg/mL,平均表观分布容积（Vz）为695.59 mL/kg,平均血浆清除率（CL）为3.77 mL/h?kg;单剂量口服帕托珠利混悬液后帕托珠利在仔猪体内主要药动学参数如下：平均消除半衰期（T1/2?）为134.05h,平均达峰时间（Tmax）为42.00h,平均峰浓度（Cmax）为14.03μg/mL,平均滞留时间（MRT）为173.19h,平均药时曲线下面积（AUC0-t）为2831.00 h?μg/mL,帕托珠利混悬液口服给药绝对生物利用度为72.08%。结果表明,帕托珠利在猪体内分布较差,消除缓慢;仔猪口服帕托珠利混悬液达峰时间较长,但吸收良好。     

仔猪专用复合酶的开发及其对乳仔猪作用效果的研究

研究旨在开发一种仔猪专用复合酶,并对其作用效果进行研究。运用仿生消化系统筛选乳猪复合酶酶谱,然后采用随机区组设计,选用健康均匀的(杜×长×大)三元杂交31日龄断奶仔猪432头,随机分为3个处理组,A组饲喂基础日粮,B组基础日粮+500 g/t乳猪复合酶,C组基础日粮+1 000 g/t乳猪复合酶,每个处理6个重复,每个重复24头猪,试验期35 d。当酶谱为蛋白酶10 000 U/g、淀粉酶500 U/g、β-葡聚糖酶300 U/g、木聚糖酶15 000 U/g、β-甘露聚糖酶2 000 U/g、α-半乳糖苷酶150 U/g时,体外营养物质消化率结果最优。动物试验结果表明,与A组相比,B组和C组的日采食量均无显著变化,C组的料肉比显著降低(P<0.05);添加乳猪酶的B组(4.62%)和C组(0.96%)腹泻率比A组(7.40%)分别显著降低了37.57%(P<0.05)和87.03%(P<0.05);仔猪发病率呈下降趋势,其中C组(1.00%)较A组(4.80%)显著降低了79.17%(P<0.05)。结果提示,乳猪复合酶可以通过仿生消化系统科学地筛选,且该仔猪专用复合酶对于乳仔猪的生长性能和抗病能力具有较好的改善作用。     

酶制剂在仔猪玉米-豆粕型饲粮中的应用

<正>1断奶仔猪消化生理特点1.1消化系统发育不完善仔猪断奶时消化器官的结构和功能发育还不完善,胃肠容积小,运动机能弱,胃排空速度快。许多研究表明,仔猪断奶后消化系统可发生显著变化,主要     

芽孢杆菌制剂对仔猪生产性能的影响

芽孢杆菌是一类好氧生长、可形成芽孢的革兰氏阳性菌 ,是国家允许使用的饲料微生物添加剂。芽孢杆菌在制剂中以内生孢子形式存在 ,孢子进入动物肠道后 ,在肠道上部能迅速复活并分泌活性很强的蛋白酶、脂肪酶、淀粉酶 ,有助于降解植物性饲料中某些复杂的碳水化合物 ,产生具有拮抗肠道致病菌的多肽类物质 ,同时通过生物夺氧消耗肠道内的氧气造成厌氧环境 ,肠道原籍优势菌大多属厌氧菌 ,而有害菌和外来菌多为需氧菌 ,从而有利于维持肠道生态平衡。此外 ,芽孢杆菌具有耐高温、耐酸碱、耐挤压 ,饲料加工对其损伤小等特性。本试验的目的是验证日粮…     

Enantioselective pharmacokinetics of ketoprofen in piglets: the significance of neonatal age

Following intravenous dose of 6mg/kg racemic ketoprofen, the chiral pharmacokinetics of ketoprofen was investigated in eight piglets aged 6 and 21days old. S-ketoprofen predominated over R-ketoprofen in plasma of the piglets in both age groups. The volumes of distribution of S-ketoprofen for the 6- and 21-day-old piglets were 241.7 (211.3-276.5) mL/kg and 155.0 (138.7-173.1) mL/kg, respectively, while the corresponding parameters for R-ketoprofen were 289.2 (250.3-334.2) mL/kg and 193.0 (168.7-220.8) mL/kg. The clearances of R-ketoprofen [948.4 (768.0-1171.2) mL/h/kg and 425 (319.1-566.0) mL/h/kg for the 6- and 21-day-old piglets, respectively] were significantly higher compared to the clearances of S-ketoprofen [57.3 (46.6-70.4) mL/h/kg and 33.8 (27.0-42.2) mL/h/kg for 6- and 21-day-old piglets, respectively]. The elimination half-life of S-ketoprofen was 3.4h for both age groups, while the elimination half-life of R-ketoprofen was 0.2h for the 6-day-old and 0.4h for the 21-day-old piglets. The clearances of both R- and S-ketoprofen were significantly higher in the 6-day-old piglets compared to when they were 21 days old. Furthermore, the volumes of distribution were larger in the youngest age group.     

Ketoprofen in piglets: enantioselective pharmacokinetics, pharmacodynamics and PK/PD modelling

The chiral pharmacokinetics and pharmacodynamics of ketoprofen were investigated in a placebo-controlled study in piglets after intramuscular administration of 6 mg/kg racemic ketoprofen. The absorption half-lives of both enantiomers were short, and S-ketoprofen predominated over R-ketoprofen in plasma. A kaolin-induced inflammation model was used to evaluate the anti-inflammatory, antipyretic and analgesic effects of ketoprofen. Skin temperatures increased after the kaolin injection, but the effect of ketoprofen was small. No significant antipyretic effects could be detected, but body temperatures tended to be lower in the ketoprofen-treated piglets. Mechanical nociceptive threshold testing was used to evaluate the analgesic effects. The piglets in the ketoprofen-treated group had significantly higher mechanical nociceptive thresholds compared to the piglets in the placebo group for 12-24 h following the treatment. Pharmacokinetic/pharmacodynamic modelling of the results from the mechanical nociceptive threshold testing gave a median IC(50) for S-ketoprofen of 26.7 μg/mL and an IC(50) for R-ketoprofen of 1.6 μg/mL. This indicates that R-ketoprofen is a more potent analgesic than S-ketoprofen in piglets. Estimated ED(50) for racemic ketoprofen was 2.5 mg/kg.     

Plasma pharmacokinetics of oral chlortetracycline in group fed, ruminating, Holstein steers in a feedlot setting

Reinbold, J. B., Coetzee, J. F., Gehring, R., Havel, J. A., Hollis, L. C., Olson, K. C., Apley, M. D. Plasma pharmacokinetics of oral chlortetracycline in group fed, ruminating, Holstein steers in a feedlot setting. J. vet. Pharmacol. Therap. 33 , 76–83. Chlortetracycline HCl (CTC) has impacted profitable livestock production since 1945. However, pharmacokinetic parameters for CTC in ruminating cattle are unavailable in peer‐reviewed literature. A total of 18 steers were randomized to 4.4, 11, or 22 mg/kg/day p.o. CTC treatment groups (n = 6). Chlortetracycline treatment was offered as one‐half of the daily dose b.i.d. (160 total doses/group) for 80 days. Blood samples were collected at selected time points throughout an 83‐day study and analyzed with a solid phase extraction technique and novel ultrahigh performance liquid chromatography‐mass spectroscopy/mass spectroscopy analytical method. Noncompartmental analysis (NCA) determined individual pharmacokinetic parameters by treatment group with coefficient of variation (CV %) estimates. A one‐compartment open model with first order absorption and elimination, where absorption rate constant was equal to elimination rate constant, was fitted using nonlinear mixed effects modeling (NLMEM). NLMEM determined the primary pharmacokinetic parameters: volume of distribution (V/F, 40.9 L/kg) and rate constant (k, 0.0478 h^?1), and the secondary parameters: dose‐normalized area under the curve (AUC/D, 0.29 h·μg/L), clearance (Cl/F, 1.8 L/kg/h), elimination half‐life (t_1/2, 16.2 h), C_max/Dose (4.5 ng/mL), and time of C_max (T_max, 23.3 h) with improved CV estimates over NCA. Dose linearity was confirmed by anova of parameters derived from NCA by treatment group. Further studies are necessary for determining absolute bioavailability and pharmacokinetic–pharmacodynamic relationships of CTC in group fed, ruminating cattle.     

免疫再生素对仔猪生产性能及免疫指标的研究

随着人类食品安全意识的提高,对饲料安全的要求也逐步增强,加上贸易壁垒的存在,迫切需要我们改变以往靠饲料中添加抗生素,高剂量铜、锌和砷制剂等有毒有害物质来提高动物生产性能的状况,用安全无公害的替代饲料添加剂产品提高生产性能是当前饲料工业发展的必然趋势。农业部2002年首批批准了安全、有效及无污染环境的新型饲料添加剂,其中由上海华扩达生化科技有限公司生产的半胱胺盐酸盐（CT2000）饲料添加剂（批号新饲证字（2002）01号）为第1号。免疫再生素是含有半胱胺盐酸盐的复合预混料添加剂。CT2000是β—CD-半胱胺盐酸盐的简称,指以β-环糊精（β-CD）和半胱胺盐酸盐等营养活性物质,采用超分子技术、仿生物膜多层包被技术和维持生理稳态技术经特殊工艺生产的生理代谢调控添加剂。     

浅析酶制剂对断奶仔猪生产性能的影响

选取健康21日龄断奶长白仔猪544头,采取随机分组的办法分成2组,第1组为试验组271头,第2组为对照组273头.试验组21-49日齿、50-70日龄阶段在对照组基础上分别添加HF-1华芬酶750g/t、1311华芬酶850g/t。饲养管理条件相同.经过50d的试验,结果表明：试验组日增重比对照组提高5.14%经显著性检验,试验组与对照组差异显著（P〈0.05）。试验组存活率比对照组高1.46％腹泻率比对照组低18.23％饲料转化率提高12．18％,头平净增收入比对照组提高9.14％     

仔痢欣对仔猪黄白痢的防治效果观察

仔猪黄白痢是由致病性大肠杆菌引起的哺乳仔猪常发的肠道传染病。其特征是下痢 ,排乳白色或灰白色糊状或粥状腥臭稀粪。具有传染性、病程短、死亡率较高的特点。主要发生于 10～ 30日龄的仔猪 ,尤以10～ 2 0日龄仔猪多发。仔痢欣其主要成分为硫酸粘杆菌素 ,免疫增强因子 (colistin,Neomycini,特殊佐剂 ) :具有杀灭病原菌 ,同时还可以迅速清除细菌代谢产物 -肠毒素和内毒素 ,修复肠黏膜、控制脱水。对常用抗菌药物耐药的菌株高度敏感。笔者于 2 0 0 2— 2 0 0 3年间 ,用湖南伟达牧业科技有限公司生产的仔痢欣 ,在湖南省武冈市湾头桥镇的4 9…     

复合酶制剂对早期断奶仔猪生长性能的影响

试验研究了复合酶制剂对96头(35±2)日龄断奶仔猪生长性能的影响。试验采用单因子设计,在相同基础日粮中分别添加0、0.5%、1.0%、1.5%的复合酶制剂组成4种日粮。5周饲养试验结果表明:加酶饲粮可明显提高早期断奶仔猪日增重,降低料重比,并能促进仔猪健康,提高经济效益。其中以0.5%酶制剂组添加效果最好,与对照组相比,平均日增重显著提高(P<0.05),料重比降低15.0%,腹泻频率降低29.7%,每千克增重成本降低0.48元,头均毛利提高26.36元。     

芽孢杆菌和果寡糖制剂对断奶仔猪肠道菌群的影响

当前动物营养研究认为，无论是抗生素(antibiotics)、益生素(probiotics) 还是益生元(prebiotics)都会影响动物肠道微生物群落的组成。