亚临床酮病对奶牛肝功能、氧化应激状态及免疫功能的影响

发布时间：2018-03-10 18:36

本文选题：奶牛　切入点：亚临床酮病　出处：《安徽农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：奶牛酮病分为临床型和亚临床型。临床型酮病的特征是奶牛血液、尿液或乳汁中酮体的含量明显升高,临床表现食欲不振、体重下降、产奶量明显下降等。而亚临床酮病未表现明显的临床症状,但血液、尿液或乳汁中酮体含量超过正常水平。目前国内外,关于临床型酮病的报道已经较多,而有关亚临床酮病的研究相对较少。本试验选择21头年龄、胎次、泌乳量和泌乳天数相近的亚临床酮病奶牛(1.2mmol·L~(-1)≤BHBA2.2 mmol·L~(-1))和非酮病奶牛(BHBA1.2 mmol·L~(-1)),分成两组。分别于清晨饲喂前,通过尾静脉采集抗凝血,用于血液常规指标检测;采集非抗凝血,用于氧化抗氧化状态、肝功能和免疫指标检测;收集新鲜乳样用于乳成分检测。同时,体外培养奶牛原代肝细胞,并添加不同浓度的非酯化脂肪酸(NEFA),分别刺激12、24和36 h,采用酶联免疫吸附法(ELISA)和实时荧光定量PCR(qRT-PCR)法检测肝细胞中氧化抗氧指标的含量、活性及mRNA水平。试验结果显示:与非酮病奶牛相比,亚临床酮病奶牛白细胞总数(WBC)、淋巴细胞总数(LYM)显著降低(P0.05),平均血小板体积(MPV)极显著降低(P0.01),而中间细胞数(MID)、中性粒细胞数(NEU)、红细胞总数(RBC)、血小板总数(PLT)、血小板压积(PCT)和血小板分布宽度(PDM)均差异不显著(P0.05)。乳脂肪比(MF)显著升高(P0.05),乳蛋白比(MP)和全脂乳固体比(TS)极显著降低(P0.01),而乳糖比(L)差异不显著(P0.05)。总抗氧化能力(TAC)显著降低(P0.05),谷胱甘肽过氧化物酶(GSH-Px)活性极显著降低(P0.01),丙二醛(MDA)含量极显著升高(P0.01),超氧化物歧化酶(SOD)的活性有降低趋势,但差异不显著(P0.05)。丙氨酸氨基转移酶(ALT)活性显著升高(P0.05);总蛋白(TP)含量显著降低(P0.05);碱性磷酸酶(AKP)活性、天冬氨酸氨基转移酶(AST)活性、总胆红素(TB)、低脂密度胆固醇(LDL-c)含量极显著升高(P0.01);总胆固醇(TCH)、高脂密度胆固醇(HDL-c)和白蛋白(ALB)含量极显著降低(P0.01);乳酸脱氢酶(LDH)活性差异不显著(P0.05)。免疫球蛋白IgG水平显著降低(P0.05);白细胞介素-2(IL-2)、白细胞介素-8(IL-8)和干扰素-γ(IFN-γ)水平有下降趋势,但差异不显著(P0.05)。不同浓度的NEFA均抑制了原代培养奶牛肝细胞中抗氧化指标(TAC、GSH-PX、SOD)的活性及mRNA表达水平,提高了丙二醛(MDA)的含量,并且呈现剂量依赖性。综上所述,亚临床酮病可造成奶牛肝功能指标发生变化;导致机体出现免疫抑制现象;体内和体外试验均证明了亚临床酮病可造成奶牛出现氧化应激。
[Abstract]:Cow ketosis is divided into clinical type and subclinical type. The characteristic of clinical ketosis is that the content of ketone body in blood, urine or milk of cow is obviously increased, and the clinical manifestation is loss of appetite and weight loss. The milk production decreased obviously, while subclinical ketosis did not show obvious clinical symptoms, but the ketone body content in blood, urine or milk exceeded the normal level. At present, there have been more reports of clinical ketosis at home and abroad. In this study, 21 subclinical ketosis cows with similar age, birth order, lactation volume and lactation days were selected and divided into two groups: BHBA2.2 mmol 路L ~ (-1)) and non-ketosis cows (BHBA 1.2 mmol 路L ~ (-1)). Collection of anticoagulant blood through tail vein for routine blood test; collection of non-anticoagulant blood for oxidation and antioxidant state, liver function and immune indexes; collection of fresh milk samples for milk component detection. At the same time, Primary hepatocytes of dairy cattle were cultured in vitro and supplemented with different concentrations of non-esterified fatty acids (NEFAA) for 1224 and 36 hours respectively. The content of oxidative oxygen resistance in hepatocytes was detected by Elisa and real-time fluorescence quantitative PCRQRT-PCRRmethod. Activity and mRNA level. The results showed that compared with non-ketosis cows, In subclinical ketosis dairy cows, the total number of white blood cells (WBCU) and the total number of lymphocytes (LYM) decreased significantly (P 0.05), and the mean platelet volume (MPV) decreased significantly (P 0.01), while the number of intermediate cells, neutrophils, erythrocyte count, platelet count, platelet count and platelet compaction were significantly decreased. There was no significant difference between PCT and PDM (P 0.05). Milk fat ratio (MFF) increased significantly (P 0.05), milk protein ratio (MPN) and whole milk solid ratio (TSS) decreased significantly (P 0.01), but lactose ratio (L) was not significantly different (P 0.05). Total antioxidant capacity (TAC) was significantly lower than that of wheat (P 0.05), and the total antioxidant capacity (TAC) was significantly lower than that of whole milk (P 0.05). The activity of glutathione peroxidase (GSH-Px) decreased significantly, the content of malondialdehyde (MDAs) increased significantly, and the activity of superoxide dismutase (SOD) decreased. The activity of alanine aminotransferase (alanine aminotransferase) increased significantly (P 0.05); the content of total protein (TP) decreased P0.05; the activity of alkaline phosphatase (AKP), aspartate aminotransferase (AST), and the activity of aspartate aminotransferase (AST). The contents of total bilirubin (TBX), low density cholesterol (LDL-c), total cholesterol (TCHG), high density cholesterol (HDL-cc) and albumin (Alb) contents were significantly increased (P 0.01); the activity of lactate dehydrogenase (LDH) was not significantly different from that of low fat density cholesterol (LDHs). The level of immunoglobulin (IgG) was significant. The levels of IL-2, IL-8, IL-8 and IFN- 纬) decreased. However, the difference was not significant (P 0.05). Different concentrations of NEFA inhibited the activity and expression of mRNA in primary cultured dairy cow hepatocytes, and increased the content of malondialdehyde (MDA) in a dose-dependent manner. Subclinical ketosis can cause changes in liver function indexes of dairy cows; lead to immunosuppressive phenomenon; in vivo and in vitro tests have proved that subclinical ketosis can cause oxidative stress in cows.
【学位授予单位】：安徽农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S858.23

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