共查询到18条相似文献，搜索用时 687 毫秒
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为了研究六茜素的安全性,试验每天给大白鼠灌服六茜素80,160,320 mg/kg,通过分析测定大白鼠的体重变化、脏器系数、血液生理生化指标及检查心脏、肝脏、脾脏、肾脏、胸腺等脏器病理变化,研究六茜素对大白鼠的亚慢性毒性.结果表明:各组大白鼠的体重变化、脏器系数、血液生理生化指标均无明显异常变化;80 mg/kg和160 mg/kg剂量组各脏器未见异常病理变化;320 mg/kg剂量组大白鼠的肝脏和肾脏器官均出现轻微的病理变化,而心脏、脾脏、胸腺和十二指肠未出现病理变化.结果说明六茜素是一种在动物体内代谢快、不易残留、低毒、高效的新型抗菌类药物. 相似文献
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为了研究六茜素注射液的安全性,进行了六茜素注射液的亚慢性毒性试验。试验每天给大白鼠灌服六茜素注射液80、160、320 mg/kg,对各组大白鼠的体重变化、脏器系数、血液生理生化指标及心脏、肝脏、脾脏、肾脏、胸腺等脏器病理变化进行了测定和分析。结果表明,试验组大白鼠的各脏器无明显肉眼可见剖检病变;试验组大白鼠的各脏器系数与对照组差异不显著(P>0.05);320 mg/kg剂量组大白鼠的肝脏和肾脏器官出现轻微的病理变化。结果说明,六茜素注射液毒性低,可以安全用于动物。 相似文献
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选用1日龄艾维茵肉仔鸡396只,随机分为7组。试验从1日龄到39日龄,连续给药39d。试验结果表明,平均日增重六茜素颗粒组均高于各药物对照组和空白对照组,达到差异显著(P<0.05)。平均日采食量六茜素颗粒组30mg/kg饲料高于盐霉素组、金霉素组和空白对照组(P<0.05)。料重比六茜素颗粒组低于牛至油组、金霉素组和空白对照组均达到差异显著(P<0.05)。死亡率六茜素各组明显低于牛至油组、金霉素组和空白对照组。六茜素溶液组和六茜素颗粒组在停药后0d时心脏、肾脏、胸肌、腹脂四种组织,均未检出六茜素残留;停药后4d时,血清、肝脏中均未检出六茜素残留;综合各项指标,六茜素颗粒组(30mg/kg饲料)促生长效果最好,无残留。 相似文献
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高效液相色谱法测定六茜素含量 总被引：4，自引：1，他引：3
采用小杨酸作内标,以甲醇：水（８０：２０）为流动相,紫外３０２ｎｍ为检测波和荨闻六茜素含量测定的反相高效液相色谱法。其对六茜的最低深度为０．５ｍｇ／Ｌ,六茜素质量浓度Ｙ在１～８０ｍｇ／Ｌ范围内与六茜素峰高和内标峰高的比Ｘ成良好的线性关系,回归方程为Ｙ＝２９．６９９Ｘ＋０．０４５,ｒ＝０．９９９９。日内与日间精密分别为０．９７％和１．０１％,对３批六茜素样品的含量测定结果表明,该方法简便、快速、准确 相似文献
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运用均匀设计，给合关联度分析和回归分析。借助电子计算机，考察了六茜素中间体的合成工艺。通过四因素试验使六茜素收率提高到新的水平。 相似文献
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应用六茜素与万菌杀星防治禽霍乱 总被引：2，自引：0，他引：2
针对六茜素在临床上存在的一些问题,对其进行了修饰,成功的研制出二代六茜素“万菌杀星”,并对其抗菌作用、毒性及临床效果比较。结果表明：万菌杀星对巴氏杆菌抗菌作用与制剂稳定性较六茜素强,而毒性较六茜素弱。 相似文献
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生物工程专业本科生遗传学实验教学的改革与实践 《畜牧与饲料科学》2016,37(2):69-69
遗传学实验课程是生物工程专业本科生必修的专业基础课。分析了遗传学实验课程教学的现状和主要问题,并针对这些问题提出了相应的改革措施和方法,以提高遗传学实验课程的教学效果和教学质量,有效地提高学生的学习主动性和创新性,培养高质量的应用性人才,为生物工程专业本科生的遗传学实验课程教学改革提供经验。 相似文献
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细胞与免疫学实验教学改革探析 《畜牧与饲料科学》2016,37(6):66-66
细胞与免疫学实验是生物学实验教学体系的重要组成部分,随着各高校人才培养目标对大学生动手能力和创新思维要求的进一步提高,高校生物学相关专业的细胞与免疫学实验的内容和教学方式必然要发生相应的变化,探讨新形势下细胞与免疫学实验教学模式改革对于提升生物学整体实验教学质量具有非常重要的意义。从改革实验教学内容、改进实验教学手段以及强化实验考核3个方面,探讨如何提高细胞与免疫学实验教学效果,以期为培养基础素质好、综合能力强的农业生物学高水平人才提供科学保证。 相似文献
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Rodolfo Ungerfeld Julia Giriboni Adolfo Toledano-Díaz Madeleine Guerrero Julián Santiago-Moreno 《Reproduction in domestic animals》2023,58(1):20-26
Transrectal ultrasonic-guided massage of the accessory sex glands (TUMASG) is a technique that allows collecting semen requiring few electrical stimuli or even no pulse. A long-acting analogue of oxytocin (carbetocin, 0.1 mg) was i.v. administered before TUMASG in 10 conscious bucks (Experiment 1) and 10 anaesthetized Iberian ibexes (Experiment 2) to shorten the time of semen collection, decrease the number of electrical stimuli and/or improve the semen quality. The ejaculated volume, concentration, quality parameters and kinetics variables of the sperm were determined in fresh semen. The time length of the procedures and the number of electric pulses applied were recorded. Furthermore, stress response indicators (number of vocalizations in Experiment 1; heart and respiratory rates, rectal temperature, cortisol levels, totals proteins and neutrophil-to-lymphocyte ratio in Experiment 2) were documented. In bucks, the administration of carbetocin tended to shorten the time needed for semen collection but no-showed differences in the fresh seminal quality. In the Iberian ibexes, there were no significant differences between groups in the time length of procedures or in the number of animals that ejaculated. Carbetocin administration only reduced the respiratory rate, did it modify fresh semen characteristics in ibexes. In conclusion, the administration of carbetocin did not appear as a useful tool to improve welfare during semen collection with TUMASG or semen quality in conscious bucks and anaesthetized ibexes, having only slight advantages related to the procedure. 相似文献
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Hiroshi Tajimi Tsugumi Yamazaki Syoko Oike Tatsuyuki Yoshida Konosuke Okada Masashige Kuwayama Hitoshi Ushijima 《Animal Science Journal》2018,89(8):1194-1200
This study was conducted to examine the utility of vitrification for bovine embryos with low‐quality grade, and simple cryoprotectants dilution method for practitioners. In Experiment 1, survival of frozen embryos was compared with that of vitrified embryos using minimum volume cooling (MVC). Then, vitrified embryos were used to confirm the optimum sucrose concentration in Experiment 2. The survival rates of embryos that had been vitrified following diluted cryoprotectants with the one‐step in‐straw method were compared with those of fresh control embryos in Experiment 3. Frozen‐thawed or vitrified‐warmed blastocysts were cultured with TCM‐199 supplemented with 100 μmol/L beta‐mercaptoethanol +5% fetal bovine serum at 38.5°C in an atmosphere of 5% CO2 in air, their survival after 24 hr were compared. The development to term of fair quality in vivo embryos after vitrification was examined in Experiment 4. Results show that survival rates of frozen‐thawed embryos were lower (p < .05) than that of vitrified‐warmed ones. When vitrified embryos were warmed in 0.3 mol/L sucrose in straws, their survival rate was 100%. The total cell numbers of vitrified‐warmed embryos were comparable to those of fresh control embryos. The six calves from 13 vitrified embryos were delivered in Experiment 4. These results indicate that MVC vitrification following one‐step cryoprotectants dilution is utilized to preserve low‐quality bovine embryos. 相似文献
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Supplementation of distiller's grains during late gestation in beef cows consuming low‐quality forage decreases uterine,but not mammary,blood flow 
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下载免费PDF全文 B. R. Mordhorst C. A. Zimprich L. E. Camacho M. L. Bauer K. A. Vonnahme 《Journal of animal physiology and animal nutrition》2017,101(5):e154-e164
Positive effects have been observed in offspring from beef cows supplemented with corn dried distillers grain with solubles (DDGS) during late gestation. The hypothesis of this study was that late gestational DDGS supplementation to beef cows would increase blood flow (BF) to the gravid uterus and mammary gland thus impacting birthweight and post‐natal growth of the offspring. Experiment 1 investigated mammary gland BF in multiparous cows during late pregnancy. Beef cows were fed a control (CON1) diet of low‐quality hay (n = 5) or a supplement diet (SUP1) of low‐quality hay with DDGS [1.7 g/kg of body weight (BW); n = 6]. In Experiment 2, multiparous late pregnant beef cows were fed either a control (CON2) diet of a low‐quality hay (n = 4) or a supplement diet (SUP2) of low‐quality hay with DDGS (1.7 g/kg of BW; n = 5). Uterine and mammary gland BF were recorded every 21 days during late gestation. In Experiment 1, there were no effects of diet or day on mammary gland hemodynamics. In Experiment 2, total and ipsilateral uterine BF was less (p ≤ 0.04) in SUP2 vs. CON2 cows and similar BF to contralateral horns. Mammary gland BF was unaltered by maternal supplementation. Even when measured in two different years in two different environments, mammary gland BF remained unaltered to DDGS supplementation. Investigations on the mechanism that may impact uterine BF during late gestation remain to be known. 相似文献
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人工授精技术与自然交配对母狐繁育等方面影响的对比试验 总被引：2，自引：2，他引：0
通过两组对比试验，人工授精比自然交配妊娠率和产仔成活率均可提高３０％。从而达到提高优质品种率，降低生产成本的目的。 相似文献
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The increased mental stress of daily life and aging of the population are serious matters in Japan. There are many studies regarding the effects of human-animal interactions on mental and physical human health, whereas there are few studies examining the effects of visiting zoos. To determine the effect of visiting zoos on human health and quality of life, two different zoos were visited by 70 participants in Experiment 1 and 163 participants in Experiment 2. In this study we administered the WHO QOL-26 questionnaire in Japanese to assess the psychological scales of participants, and blood pressures and pulse rates were measured to assess their physical scales. We also used pedometers to count the number of steps taken during zoo visits. Both zoo visits decreased blood pressure and participants demonstrated more than 6000 steps during each visit. The quality of life sub-scale scores were improved after zoo visits. 相似文献
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生物化学实验的教学现状与改革探索 总被引：1，自引：0，他引：1
为进一步推动高等院校生物化学实验课程教学改革,满足新形势下创新型人才培养的需求,从培养学生的实践动手能力、知识创新能力和科学探索精神的角度出发,探讨了当前生物化学实验课程教学过程中存在的一些问题和不足,对生物化学实验课程教学进行了一些初步的改革和实践探索。这些措施既调动了学生的学习积极性,又锻炼了学生的动手能力,提高了实验课的教学质量。 相似文献