高精料诱导的SARA对泌乳期山羊血液和瘤胃液中皮质醇的影响  

Effects of SARA induced by high level concentrate on cortisol concentrations in serum and rumen fluids of the goats during lactation

作　　者：贾媛媛[1] 王绍庆[1] 常广军[1] 张源淑[1] 庄苏[1] 倪迎冬[1] 沈向真[1] 陈杰[1] 赵茹茜[1] 

机构地区：[1]南京农业大学动物医学院农业部动物生理生化重点开放实验室,江苏南京210095

出　　处：《草业学报》2012年第4期259-266,共8页Acta Prataculturae Sinica

基　　金：国家重大基础研究发展计划973项目(No.2011CB100802)资助

摘　　要：选择7只装有永久性瘤胃瘘管的泌乳中期山羊,2×2拉丁方设计,分别饲喂精粗比为6∶4和4∶6的饲料,通过饲喂精粗比6∶4饲料建立泌乳期山羊瘤胃亚急性酸中毒(subacute ruminal acidosis,SARA)模型,研究SARA时山羊血液和瘤胃液中皮质醇浓度、肝脏皮质醇受体(glucocorticoid receptor,GR)mRNA表达及其他相关指标的变化。结果表明,精粗比6∶4日粮饲喂2周后成功诱导SARA状态(SARA组),采食后瘤胃液pH值低于5.8持续时间约6h,而精粗比为4∶6组山羊瘤胃液pH均高于6.0(对照组)。高精料日粮处理对瘤胃pH和乳酸以及瘤胃液和血浆内的脂多糖、皮质醇浓度有显著性影响(P<0.05),采食前SARA组山羊瘤胃液中乳酸浓度显著高于对照组(P<0.05),采食后0～4h乳酸含量下降,6～10h时逐渐增加并极显著高于对照组(P<0.01);2组间瘤胃液中脂多糖浓度无显著性差异(P>0.05),SARA组血浆脂多糖浓度在采食前和采食后6h均显著高于对照组(P<0.05);采食前SARA组山羊血液中皮质醇浓度高于对照组(P=0.05),但采食后6h两组间无显著差异(P>0.05);2组山羊瘤胃液中皮质醇浓度在采食后2,4和6h分别显著高于对照组(P<0.05),但在采食前和采食后10h无显著差异(P>0.05)。Real-time PCR结果显示,SARA组山羊肝脏中GR mRNA表达显著下调(P<0.05)。本研究结果显示,泌乳期山羊发生SARA时糖皮质激素水平升高,负反馈下调肝脏GR的表达水平,提示SARA时机体处于应激状态,可能引起肝脏的物质代谢和营养物质重分配的改变。Seven goats fitted with permanent rumen cannulas in mid-lactation were used in a 2×2 latin square experiment design with different concentrate to roughage ratio of 6∶4 and 4∶6 respectively.Set up the subacute ruminal acidosis（SARA） model by the diet with concentrate to roughage ratio of 6∶4 to study the variations of cortisol concentration in the blood and rumen fluid and glucocorticoid receptor mRNA of goat in mid-lactation.SARA was induced successfully by feeding the SARA group with the diet with concentrate to roughage ration of 6∶4.pH of the rumen fluid of SARA group was below 5.8 after feeding,lasting for about 6 hours while pH of the rumen fluid of control group（concentrate to roughage ratio of 4∶6） was above 6.0.pH and lactic acid of the rumen fluid,LPS and cortisol of rumen fluid and blood were affected by dietary modulation（P0.05）.Comparing with that in the control group,the concentration of lactic acid in rumen fluid of SARA group was significantly high（P0.01） before feeding and then decreased in four hours after feeding and increased during 6-10 h after feeding,significantly higher（P0.01）.Concentration of LPS in rumen fluid was no significance between the two groups at the same time points（P0.05）,but concentration of LPS in blood of SARA group was significancantly higher than control in 0 and 6 h after feeding（P0.05）;the concentration of cortisol in blood and rumen fluid of SARA group was higher than that in the control group（P=0.05） before feeding,but there was no significance between the two groups after 6 hours after feeding（P0.05）;concentration of cortisol in rumen fluid was significantly higher than control in 2,4 and 6 h after feeding,but no significance between the two goups after 10 hours after feeding（P0.05）.Results of Real-time PCR showed that GR mRNA downgraded significantly（P0.05）.Our results indicates that SARA goats were in stress situation with a significantly higher glucocorticoid concentrations in serum and rumen fluids,accompanied

关 键 词：精粗比 亚急性瘤胃酸中毒 皮质醇 肝脏 山羊 

分 类 号：S858.27[农业科学—临床兽医学]