乳房炎对奶牛乳成分、氧化应激水平、炎性因子含量昼夜节律性变化的影响  

Effect of mastitis on circadian variation of milk composition,oxidative stress levels,and inflammatory factor content in dairy cows

作　　者：金梦冬 张靖 王博 刘田 刘祖培 张海森 靳亚平[1,2] 陈华涛 JIN Mengdong;ZHANG Jing;WANG Bo;LIU Tian;LIU Zupei;ZHANG Haisen;JIN Yaping;CHEN Huatao(College of Veterinary Medicine,Northwest A&F University,Yangling,Shaanxi 712100,China;Key Laboratory of Animal Biotechnology of the Ministry of Agriculture and Rural Affairs,Yangling,Shaanxi 712100,China)

机构地区：[1]西北农林科技大学动物医学学院,陕西杨凌712100 [2]农业农村部动物生物技术重点实验室,陕西杨凌712100

出　　处：《中国兽医学报》2023年第9期1924-1934,1940,共12页Chinese Journal of Veterinary Science

基　　金：陕西省农业农村厅省级农业专项基金资助项目(NYKJ-2021-YL(XN)10);国家自然科学基金青年科学基金资助项目(31602125);校级大学生创新创业训练计划资助项目(x202210712221)。

摘　　要：通过采集乳房炎阳性(n=5)和健康奶牛(n=10)3个时间点(0:00、8:00、20:00)的血液和乳汁样本,使用乳成分分析、酶联免疫吸附试验和实时荧光定量PCR等方法检测两组奶牛血液和乳汁中氧化应激水平、炎性因子含量与生物钟基因表达的差异。结果发现:健康奶牛在3个时间点的乳脂率、乳糖率、总固体和尿素氮含量均呈现先下降后上升的趋势;与健康组相比,乳房炎组乳脂率、乳糖率、总固体与尿素氮含量显著下降,乳蛋白率和体细胞数(somatic cell count,SCC)显著升高。奶牛乳汁中的β-N-乙酰氨基葡萄糖苷酶活力、丙二醛含量与过氧化氢酶活力均具有显著性差异,且乳房炎组血浆和乳汁中的氧化应激相关因子含量显著升高。与健康组相比,乳房炎组血浆中促炎因子IL-8与IL-1β和生物钟基因NR1D1、CRY1的表达差异显著;奶牛乳汁中的炎性因子、生物钟基因和酪蛋白基因的表达均具有昼夜差异,且乳房炎组乳汁中的促炎因子CCL5、IL-8、IL-1β、IL-6与抗肿瘤因子TNF-α的表达显著升高,抗炎因子IL-10和生物钟基因NR1D1、BMAL1、DBP的表达显著降低,酪蛋白基因CSN1S1、CSN2、CSN3的表达显著降低,并且丧失昼夜差异。综上所述,奶牛乳成分具有昼夜变化;健康奶牛体内的氧化应激因子含量、炎性因子含量、生物钟基因和酪蛋白基因的表达均呈现昼夜变化,在患乳房炎的奶牛血液和乳汁中氧化与抗氧化系统失衡,氧化应激水平升高,乳汁中生物钟基因和酪蛋白基因的表达降低,提示奶牛体内生物钟系统的改变可能与乳房炎的发生发展过程存在一定的潜在联系。这些研究结果为从生物钟角度防制奶牛乳房炎提供了前期基础和理论依据。This study aims to investigate the effects of mastitis on circadian rhythmic changes of milk composition,oxidative stress levels and inflammatory factor content in dairy cows,with a view to providing a theoretical basis for the control of mastitis in dairy cows from the circadian clock perspective.In this study,blood and milk samples were collected from mastitis-positive(n=5)and healthy cows(n=10)at different time points(0:00,8:00,20:00).The differences in oxidative stress levels,inflammatory factor content and clock genes expression in blood and milk in two groups were investigated by milk composition detection,enzyme-linked immunosorbent assay and real time-quantitative PCR(RT-qPCR).The results revealed that milk fat percentage,lactose percentage,total solids and urea nitrogen contents of healthy dairy cows were decreasing and then increasing at three-time points.Compared with the healthy group,the percentage of milk fat,lactose,total solids,and urea nitrogen in the mastitis group was significantly decreased,and the percentage of milk protein and somatic cell count(SCC)were significantly increased.There were significant differences inβ-N-acetylaminoglucosidase,malondialdehyde content,and catalase activity in milk between the healthy and mastitis groups.The levels of oxidative stress-related factors in plasma and milk of the mastitis group were significantly increased.Compared with the healthy group,plasma levels of pro-inflammatory factors IL-8and IL-1βand clock genes NR1D1and CRY1 in the mastitis group were significantly different.The expressions of inflammatory factors,clock genes,and casein genes in the milk of dairy cows have diurnal differences.The levels of pro-inflammatory factors CCL5,IL-8,IL-1β,IL-6and anti-tumor factor TNF-αin milk were significantly increased.Anti-inflammatory factor IL-10and clock genes NR1D1,BMAL1,and DBP were significantly decreased.Casein genes CSN1S1,CSN2,and CSN3were significantly decreased,with a loss of diurnal differences.In conclusion,there are diurnal variations in mil

关 键 词：乳成分 氧化应激 昼夜节律 乳房炎 

分 类 号：S857.2[农业科学—临床兽医学]