Evaluation of oxidative stress in hunting dogs during exercise

Exercise has been shown to increase the production of reactive oxygen species (ROS) to a point that can exceed antioxidant defenses, to cause oxidative stress. The aim of our trials was to evaluate oxidative stress and recovery times in trained dogs during two different hunting exercises, with reactive oxygen metabolites-derivatives (d-ROMs) and biological antioxidant potential (BAP) tests. A group of nine privately owned Italian hounds were included. A 20-min aerobic exercise and a 4-h aerobic exercise, after 30 days of rest, were performed by the dogs. Our results show an oxidative stress after exercise due to both the high concentration of oxidants (d-ROMs) and the low level of antioxidant power (BAP). Besides, the recovery time is faster after the 4-h aerobic exercise than the 20-min aerobic exercise. Oxidative stress monitoring during dogs exercise could become an interesting aid to establish ideal adaptation to training.     

高效液相色谱法测定猪血浆及组织中喹赛多及其脱二氧代谢物

建立了测定猪血浆及肝脏、肾脏、肌肉等组织中的喹赛多及其代谢物脱二氧喹赛多的高效液相色谱(HPLC)法.血浆样用甲醇沉淀蛋白后离心取上清液进样测定.组织样先用乙腈匀浆,用正己烷脱脂后作HPLC检测.色谱柱为ODS C18柱;流动相血浆样测定为乙腈水(2080),组织样测定为甲醇水(4258),流速为1.0 mL/min;紫外检测波长305 nm.药物工作液质量浓度范围为0.005～0.500 mg/L时,血浆样品及组织样品测定条件下药物质量浓度与响应值均具良好线性关系,相关系数＞0.999.血浆中药物质量浓度为0.02、0.10、0.50 mg/L时,喹赛多及脱二氧喹赛多的回收率均大于70%,组织中药物含量为0.05、0.20、1.00μg/g时,肌肉样品的回收率均大于70%,肝脏、肾脏样品则为50%～80%.本试验条件下,喹赛多及其脱二氧代谢物的最低检出质量浓度,血浆样品分别为0.01、0.02mg/L,组织样品2种检测物均为0.025μg/g.测定了工作液3种质量浓度0.01、0.05、0.25 mg/L的仪器精密度,日内相对偏差＜8.0%,日间相对偏差＜17.0%.     

日粮添加镁、硒、铬对热应激肉仔鸡血清生化和血液流变学的影响

试验旨在研究热应激情况下镁、硒、铬联合添加对肉仔鸡血清生化指标和血液流变学的影响。选用240只1日龄AA肉公鸡,随机分为4个处理,每个处理6个重复。T1为常温对照组,T2、T3、T4为热应激组。T1、T2饲喂基础日粮,T3、T4在基础日粮中分别添加镁、硒、铬2000、1.5、1.5mg/kg和4000、3.0、3.0mg/kg。结果表明:T3、T4组热应激鸡只死亡率显著降低,血清TP、ALB、GLOB、HDL水平显著升高(P0.05),GLU、BUN、TC含量显著降低(P0.05)。同时,T3、T4组的GPT、CK酶活力及低切变率下的全血黏度均显著降低(P0.05)。试验表明,联合添加镁、硒、铬能有效改善热应激肉鸡的血液生化和血液流变学指标,减轻热应激对机体的损伤,从而降低鸡只死亡率。     

Salivary testosterone measurements in growing pigs: validation of an automated chemiluminescent immunoassay and its possible use as an acute stress marker

This study aimed to validate the use of an automated chemiluminescent immunoassay analyser for salivary testosterone measurements in growing pigs and study how circadian pattern during daytime and stress can influence its values. The test method had intra- and inter-assay coefficient of variation lower than 10%. The method showed good linearity and recovery, and detection limits were low enough to detect salivary testosterone levels. No significant differences were observed in testosterone concentrations at different sampling time, and age and gender did not influence circadian pattern. In addition, this assay was used to quantify testosterone in two models of acute stress and, in both cases, significant increases (P < 0.01) in salivary testosterone were detected. Therefore, the automated assay system tested for porcine testosterone determinations would be suitable for its use in saliva samples and, furthermore, salivary testosterone levels could be used as a possible marker of acute stress in pigs.     

仔猪高死亡率腹泻病因探讨

2010年4月以来,全国各地先后出现高死亡率吮乳仔猪腹泻,以冬春寒冷季节多发、持续时间长、高死亡率为特征,日龄越小死亡率越高,用药物及生物制剂均无法有效控制,给养殖业带来巨大的经济损失。按照流行性腹泻病毒感染、霉菌毒素及中毒等采取相应的防治措施,效果均不明显。按中兽医整体观念、辨证论治,将两方面病因有机结合起来,分析该疾病的病理机制,采用中药复方进行临床验证,取得较好的防治效果,为该病的预防和治疗提供了新的思路与方法。     

Research on the Antioxident Function of Sulforaphane on the Leydig Cells of Cadmium Exposured Mice

The study was aimed to explore the antioxident function of sulforaphane (SFN) on the leydig cells of cadmium (Cd) exposured mice.Cd and SFN were added to the cell culture medium of TM3 cell, half inhibitory concentration (IC₅₀) of Cd and SFN safe dose range were determined.The tested model was set up,and the relative survival rate of TM3 cells, lactate dehydrogenase (LDH) activity and cell antioxidant levels were determined to study the antioxident function of SFN to cadmium exposured mice.The results showed that:①With the increase of Cd concentration,the relative survival rate of TM3 cells was decreased,and the IC₅₀ of Cd was 51.4 μmol/L;Within a certain concentration range,SFN could increased the cells survive rate,but there was toxicity when the SFN concentration was more than the scope,and the greater the concentration,the greater the toxicity. At experimental condition,SFN safety concentration were 2.5,5 and 10 μmol/L.②Compared with the control group,the GSH content,the T-SOD and GSH-Px activities in Cd group were significantly or extremely significantly decreased (P < 0.05;P < 0.01),and the LDH activity,the MDA content were increased.Additionally,the LDH activity and MDA content of SFN groups were decreased,while others three indexes were increased. Compared with Cd group,the GSH content,the T-SOD and GSH-Px activities of Cd+SFN groups were significantly or extremely significantly increased (P < 0.05;P < 0.01),however,the LDH activity,MDA content were decreased. The result indicated that SFN had the antagonism effect on toxicity of Cd in TM3 cell.     

外源钙离子缓解海水胁迫下菊芋光合能力下降的研究

用不同浓度Ca2 对处在30%海水胁迫处理下的菊芋幼苗进行化学调控,研究了Ca2 对海水胁迫下菊芋叶片中超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量、相对电导率、净光合速率(Pn)、气孔导度(Gs)和荧光参数的影响,以探索外源Ca2 对缓解植物海水胁迫下光合作用下降的作用机制。结果表明,在30%海水胁迫下,菊芋的正常生理代谢明显受到抑制;当施入钙离子后,盐对菊芋幼苗的胁迫不同程度降低,其中以10 mmol/L Ca2 效果最好,可有效防护胁迫所致的氧化损伤,从而维持较高的SOD活性,抑制脂质过氧化作用,使叶片在盐胁迫条件下,维持较高的PSⅡ的电子传递强度(Fm/F0)、PSII光化学效率(Fv/Fm)、PSⅡ量子效率(ΦPSⅡ)、光化学淬灭系数(qP)、Pn、Gs和较低的非光化学淬灭系数(qNP)。这说明外源的Ca2 一定程度上弥补了盐胁迫导致的Ca2 亏缺,可有效缓解海水胁迫所致的氧化损伤,使植物维持较正常的生理活动,稳定细胞膜结构,维持体内离子吸收平衡,维持较高的光合速率,保护光合机构。     

AMPK对动物营养代谢的调节作用

AMPK是一种能被腺苷一磷酸(AMP)激活的蛋白激酶。该酶的作用底物包括β—羟基—β甲基—戊二酸单酰CoA还原酶(HMGR) ,乙酰辅酶A羧化酶(ACC) ,激素敏感脂酶(HSL) ,糖原合成酶。当细胞能量被耗竭、腺苷一磷酸/腺苷三磷酸比(AMP/ATP)增加时 ,AMPK被活化 ,继而通过调节上述底物酶而改变脂类和碳水化合物代谢 ,使其朝着抑制ATP消耗过程、促进ATP生成反应的方向进行 ,从而使细胞能量得到迅速恢复。AMPK的这种“燃料开关“作用在动物抵御和适应环境应激的过程中起着重要作用。AMPK可能参与家畜应激营养代谢及营养代谢疾病的调节     

高温条件下复合抗应激剂对肉鸡的影响

本文研究了高温条件下复合抗应激剂对肉鸡的影响。结果表明：经历３２ ℃一周的５ ～８ 周龄肉鸡采食量、增重、饲料转化率均显著下降（Ｐ＜ ０ ．０１） ,饮服复合抗应激剂显著改善增重和饲料转化率（Ｐ＜ ０ ．０１） , 采食量未见明显改变,饲料转化率达到常温水平。３２ ℃１６ 小时血浆皮质酮、Ｔ３ 显著下降（Ｐ＜ ０ ．０１） 、Ｔ４ 显著升高（Ｐ＜ ０ ．０１） ;３２ ℃１２０ 小时血浆皮质酮、Ｔ３ 升高并超出常温组（Ｐ＜ ０ ．０５） 、Ｔ４ 较１６ 小时下降但仍高出常温组（Ｐ＜ ０ ．０５） 。饮服复合抗应激剂时血浆皮质酮、Ｔ３ 、Ｔ４ 显现相同变化规律,但这种变化得到显著缓解     

苗期紫花苜蓿品种抗旱性初步研究

运用多元统计分析方法,以来自、美国、澳大利亚、加拿大及中国的22个紫花苜蓿Medicago sativa品种（种群）为试验材料,对紫花苜蓿在苗期进行短期干旱胁迫,依据试验测定的15个形态指标和生理指标,应用主成分分析、聚类分析法,对22个紫花苜蓿品种试验材料的抗旱能力进行综合评价。通过运用主成分分析法将15项相关的抗旱性指标简化为5个独立且功能明确的主成分,并以5个主成分的得分系数运用聚类分析法把22份材料聚为三大类,从而将22份材料分为强抗旱性品种、中抗旱性品种、弱抗旱性品种,为下一步抗旱机制的研究提供参考。