低温环境下饲粮核黄素添加水平对蛋鸭激素分泌的影响

本试验旨在研究低温环境下饲粮核黄素添加水平对蛋鸭激素分泌的影响.试验采用两因素有重复完全交叉设计,温度设2个水平[适温(18±1)℃,T1;低温(2±1)℃,T2];核黄素设3个水平,在基础饲粮中分别添加4、16、32 mg/kg 核黄素.选用12周龄健康的金定鸭(母)144只,随机分成6个处理,每个处理6个重复,每个...     

猪戊型肝炎病毒ORF3蛋白影响HepG2细胞核黄素代谢的lncRNA-mRNA调控网络的鉴定

为初步鉴定并挖掘出猪戊型肝炎病毒(Hepatitis E virus,HEV)ORF3蛋白影响HepG2细胞核黄素代谢信号通路的lncRNA-mRNA调控网络,本试验通过构建腺病毒过表达载体,制备高滴度过表达腺病毒,介导猪 HEV-ORF3在HepG2细胞中实现过表达。Western blotting检测ORF3蛋白过表达成功后,运用lncRNA高通量组学测序,筛选出差异表达的lncRNA并进行靶向差异基因预测,对lncRNA靶向差异基因进行GO功能和KEGG通路富集分析,初步鉴定出与核黄素代谢信号通路相关的lncRNA-mRNA调控网络。Western blotting结果显示,在约为12 ku处出现目的条带,说明成功实现腺病毒介导猪HEV-ORF3在HepG2细胞中过表达。lncRNA高通量组学测序结果显示,共发现102个显著差异表达lncRNAs表达量上调,80个显著差异表达lncRNAs表达量下调。GO功能和KEGG通路富集分析显示,初步挖掘出lncRNA(MSTRG.13995.2)和lncRNA(MSTRG.1960.1)可能是与核黄素代谢信号通路相关的显著差异表达lncRNA,分别通过顺式调控其靶向基因APC-5和FLAD1来影响核黄素代谢信号通路。本试验初步鉴定出lncRNA(MSTRG.13995.2)-APC5和lncRNA(MSTRG.1960.1)-FLAD1可能是影响HepG2细胞核黄素代谢信号通路的lncRNA-mRNA调控网络。     

维酶素生产菌阿舒假囊酵母的发酵培养基优选

本研究采用二次通用旋转组合回归设计方法，对维酶素发酵培养基豆腐渣中添加麦麸、小米和玉米粉的最优化组合进行定量研究。建立了维酶素产量形成的培养基的反应模式，利用回归模式对培养基的最优化组合和各单因子要素反应规律及其互作效应进行了探讨。     

Serum chloramphenicol levels and the intramuscular bioavailability of several parenteral formulations of chloramphenicol in ruminants

Summary

Serum chloramphenicol concentrations were determined by microbiological and chemical assay methods in cows, ewes, and goats treated parenterally with seven different veterinary parenteral chloramphenicol products, including the water soluble sodium succinate ester of chloramphenicol and solutions of 20%, 25% and 50% of chloramphenicol base in various organic solvents. Serum drug concentrations were analyzed for the effect of product formulation differences, dosage, whether the drug was administered i.m. at a single body site or to two sites, and the method of assay, on the absorption from the injection site, peak drug levels, and the persistence in serum of effective concentrations of the drug i.e. 5 to 10 ug / ml. Although differences were observed among the 6 products containing chloramphenicol base in respect to absorption rate and peak serum drug levels, and although these differences significantly influenced the persistence of microbiologically‐active serum drug concentrations at the level of ≥ 10 μg / ml, they did not at the level of ≥ 5 μg / ml.

In the animal species examined, injections given at 2 sites appeared to influence the duration of predetermined serum drug levels more than the differences among the products in respect of the absorption and elimination rates from serum, the peak serum concentrations, and the dose. The shapes of the concentration‐to‐time curves in cows and ewes injected with the same dose of a given product were essentially the same, but they were different in goats. Serum chloramphenicol concentrations measured chemically after treatment with chloramphenicol base were 20% to 46% higher than those measured microbiologically.

For 60 minutes after the sodium succinate ester had been administered i.v. and i.m. to ewes, the chemically determined chloramphenicol levels were more than twice as high as the respective concentrations determined by microbiological assay, but thereafter, the magnitude of those differences was not greater than observed after treatment with chloramphenicol base.

Intramuscular bioavailability of the products containing chloramphenicol base injected at 2 sites was rather poor (51% to 80.5%ofthe dose) and even lower values were calculated after injection at a single site.

Results are briefly discussed of the effect of dosage form on the persistence of microbiologically effective serum drug levels. A dose of at least 50 mg / kg to be administered i.m. at two sites are essential prerequisits for chloramphenicol therapy in ruminants.     

外源诱抗剂对烟草青枯病的诱抗效果研究

为研究外源诱抗剂对烟草青枯病的诱抗效果,利用外源水杨酸、核黄素和草酸等诱抗物质处理烟苗,研究3 种物质处理后接种青枯病对相关酶活性、可溶性蛋白含量、病情指数和相对防效的影响。结果表明,3 种诱抗物质均能提高叶片内的苯丙氨酸酶(PAL)、过氧化物酶(POD)、多酚氧化酶(PPO)的活性及可溶性蛋白含量,但却降低了过氧化氢酶(CAT)活性。3 种物质均可诱导烟草对青枯病的抗性,前期以核黄素的诱抗效果较好,平均防效达55.71%（5 天）,且与水杨酸差异不显著;中期（8 天）以水杨酸防效较好,防效为42.20%,显著高于其他2种物质;后期水杨酸的诱抗效果好,平均防效达33.67%（11天）。     

核黄素缺乏对1～28日龄北京鸭生长性能、器官指数和血浆生化指标的影响

本试验旨在研究核黄素缺乏对1~28日龄北京鸭生长性能、屠宰性能、器官指数、组织核黄素含量及血浆生化指标的影响。采用单因子完全随机试验设计,选取360只1日龄健康的雄性北京鸭,随机分为3个组,即核黄素缺乏组、采食配对组(人为控制该组采食量与核黄素缺乏组一致)和自由采食对照组,每组12个重复,每个重复10只鸭。核黄素缺乏组试验鸭饲喂核黄素缺乏饲粮(实测核黄素含量为1.38 mg/kg),采食配对组和自由采食对照组饲喂核黄素充足饲粮(在核黄素缺乏饲粮基础上添加10 mg/kg核黄素)。试验期为28 d。结果表明:与采食配对组和自由采食对照组相比,核黄素缺乏组试验鸭的平均日增重、胸肌率和腿肌率显著降低(P0.05),料重比和死亡率显著升高(P0.05),肝脏指数、心脏指数和胰腺指数显著提高(P0.05),血浆核黄素、肝脏核黄素和黄素单核苷酸含量显著降低(P0.05),血浆谷草转氨酶活性及总胆固醇和甘油三酯含量显著提高(P0.05)。由此得出,核黄素是北京鸭生长发育必需的营养素;饲粮中缺乏核黄素可降低1~28日龄北京鸭的生长性能和组织中核黄素含量,可提高肝脏指数并导致血浆总胆固醇和甘油三酯含量及谷草转氨酶活性升高。     

Radiation effect on ascorbic acid and riboflavin biosynthesis in germinating soybean

The influence of irradiation on biosynthesis of ascorbic acid and riboflavin in germinating soybean seeds in tap and distilled water at ambient (25–35°C) conditions was investigated. Ascorbic acid was not detectable in the original seeds and the initial level of riboflavin was 3.3 g/g. The rate of synthesis of these vitamins increased with increasing germination time up to 72–96hr followed by a decreasing pattern depending upon the treatment. The effect of irradiation and germination on the synthesis of these vitamins was statistically significant (P<0.01). Maximum amounts of ascrobic acid 16.2 and 15.0 mg/ 100 g (fresh weight basis) were found in the 0.10 kGy sample after 72 hr of germination in tap and distilled water, respectively. However, a radiation dose of 0.20 kGy resulted in the development of maximum values of riboflavin, 30.0 and 27.0 g/g (dry weight basis) on germination in tap and distilled water respectively.     

Display practices and changes in riboflavin content of non-fermenting palm juice

Changes in riboflavin content of industrially bottled palm juice stored at different light intensities similar to display patterns practised by traders was studied. The loss of riboflavin in the first 24 hours was significantly higher than in the second 24 hours in both transparent (P<0.001) and green bottles (P<0.02) exposed to bright sunlight. Riboflavin loss from samples stored in transparent bottles occurred at a faster rate (24–71% of initial) than from samples in green bottles (0–29%) over a 36-hour period. Further loss of riboflavin did not occur over the next 36 hours due to cool weather conditions. In contrast, only 6% of initial riboflavin was lost after 72 hours of continuous exposure to fluorescent light: this increased by 53% by the ninth week. The data showed that riboflavin loss from bottled palm juice varied with the container, the environmental conditions and period of storage. It is recommended that palm juice should be displayed in dark bottles and protected from bright light.     

草鱼幼鱼对饲料中核黄素的需要量

配制核黄素含量分别为0.54、2.32、4.08、5.78、9.28和19.35 mg/kg的6种纯化饲料,投喂初始均重为(11.21±0.16)g的草鱼幼鱼8周,通过研究核黄素对其生长性能、肝胰脏中D-氨基酸氧化酶(D-AAO)与肠道中消化酶活力及体成分的影响,以确定草鱼幼鱼对饲料中核黄素的需要量。每种饲料设3个重复,每个重复放养20尾鱼。结果表明:0.54和2.32 mg/kg组草鱼幼鱼的成活率显著低于其他各组(P0.05);随着饲料中核黄素含量的增加,草鱼幼鱼的增重率、特定生长率、饲料效率、肝胰脏中D-AAO及肠道中消化酶活力均先升高后趋于稳定,当饲料中核黄素含量为5.78 mg/kg时,以上指标均达到最大值;5.78 mg/kg组的肝体比显著高于0.54 mg/kg组(P0.05),但饲料中核黄素含量对脏体比、肥满度及全鱼的水分、粗蛋白质、粗脂肪和粗灰分含量无显著影响(P0.05)。折线模型回归分析表明,草鱼幼鱼获得最佳生长时对饲料中核黄素的需要量为5.54 mg/kg;肝胰脏中D-AAO活力达到最佳时对饲料中核黄素的需要量为5.99 mg/kg。     

１～２１日龄不同性别北京鸭核黄素需要量的估测

本试验旨在估测 １～２１日龄不同性别北京鸭核黄素的需要量。采用 ２（性别：公、母）×９（饲粮核黄素水平：１．２、３．２、５．２、７．２、９．２、１１．２、１３．２、１５．２、４１．２ｍｇ／ｋｇ）双因子完全随机试验设计,选取体重相近的 １日龄健康的 Ｚ３系北京鸭公鸭和母鸭各 ３６０只,公鸭和母鸭均随机分为 ９组,每组 ５个重复,每个重复 ８只鸭。结果表明：性别对 １～２１日龄北京鸭的平均日增重和料重比有显著影响（Ｐ＜０．０５）,对平均日采食量、血浆核黄素水平以及血浆谷丙转氨酶（ＡＬＴ）、天冬氨酸转氨酶（ＡＳＴ）、乳酸脱氢酶（ＬＤＨ）活性均无显著影响（Ｐ＞０．０５）。饲粮核黄素水平对 １～２１日龄北京鸭平均日增重、平均日采食量、料重比、血浆核黄素水平以及血浆ＡＬＴ、ＡＳＴ、ＬＤＨ活性均有显著影响（Ｐ＜０．０５）。结果提示,分别以平均日增重、平均日采食量、料重比和血浆核黄素水平为评价指标,采用折线模型估测 １～２１日龄北京鸭公鸭核黄素需要量分别为３．３１、３．２４、５．２０、３．８２ｍｇ／ｋｇ,母鸭核黄素需要量分别为 ３．２７、３．１９、３．３３、３．８４ｍｇ／ｋｇ。