高精料日粮对干奶期奶山羊肝脏中游离氨基酸重分配的影响  

The effects of high concentrate diets on the redistribution of free amino acids in the liver of goats in dry period

作　　者：曹洋[1] 叶平生[1] 荣超[1] 李林[1] 张瑜娟[1] 张源淑[1] 沈向真[1] 

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

出　　处：《南京农业大学学报》2016年第2期289-296,共8页Journal of Nanjing Agricultural University

基　　金：国家973计划项目(2011CB100802)

摘　　要：[目的]探究高精料日粮饲喂条件下,干奶期奶山羊肝脏中氨基酸的分配变化及其可能机制,为干奶期奶山羊的科学饲养管理提供理论基础。[方法]选用干奶期奶山羊12只,2×2拉丁方试验设计。前10 d为适应期,期间安装瘤胃瘘管并进行肝脏多血管瘘手术。适应期后,随机分为2组,分别饲喂精粗比为40∶60(对照组)和60∶40(高精料组)日粮,每期4周。每期试验结束,采集颈静脉、肝门静脉和肝静脉血液,采集饲喂后0、1、2、4、6、8和10 h的瘤胃液,采集肝脏组织。检测瘤胃液p H值,检测进出肝脏血液和肝脏组织匀浆液中FAA的含量及外周血液中脂多糖(LPS)和丙二醛(MDA)含量及超氧化物歧化酶(SOD)、肌酸激酶(CK)、乳酸脱氢酶(LDH)、丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)活性,并检测肝脏组织中CK、LDH、ALT和AST酶活性。[结果]与对照组相比,高精料组瘤胃p H值降低,并出现亚急性瘤胃酸中毒(SARA);高精料组奶山羊肝门静脉血中FAA含量升高,而肝静脉血中FAA含量降低。肝脏组织匀浆中FAA含量降低;颈静脉血液中LPS含量极显著升高(P<0.01),MDA含量升高。SOD酶活性下降(P>0.05),CK酶活性升高(P>0.05),LDH酶活性极显著升高(P<0.01),ALT和AST酶活性均显著升高(P<0.05);肝脏组织中CK、LDH、ALT和AST酶活性均升高(P>0.05)。[结论]高精料饲喂,导致干奶期奶山羊肝脏中AA进肝多而出肝少,肝脏组织中储存的AA减少,AA发生重分配。其机制可能是在高精料日粮饲喂条件下,机体出现SARA,引起循环血液中LPS含量增加,激活机体的氧化应激,同时肝脏受到一定程度的损伤,共同导致肝脏中AA消耗增多。[Objectives]The aim of this study was to investigate the effects and the potential mechanism of high concentrate diets on the redistribution of free amino acids in the liver in dry period goats,and provide the theoretical basis for scientific feeding management of the dry period of dairy goats. [Methods]Twelve goats during nonlactating dry periods were employed in 2×2 Latin square experimental design. After first 10 days adaptation,the rumen fistula surgery and vascular fistulas surgery were done during this period. After adaptation period,the goats were randomly divided into 2 groups fed diets with forage to concentrate ratios 40 ∶60（ normal control group） and60 ∶40（ high concentrate group）,respectively. Each period lasted for 4 weeks. At the end of each term,blood from jugular vein,hepatic vein and portal vein were collected,and ruminal fluids were collected through the rumen fistula. The liver tissues were sampled immediately after goats slaughtered. We detected the p H value of rumen fluid after 0,1,2,4,6,8,10 hours from feeding,and the concentration of free amino acids in the blood of hepatic vein,portal vein and the homogenate of liver. The contents of lipopolysacharide（ LPS） and malonaldehyde（ MDA） in peripheral blood,and the enzyme activities of superoxide dismutase（ SOD）,creatine kinase（ CK）,lactic dehydrogenase（ LDH）,alamine aminotransferase（ ALT） and aspartate aminotransferase（ AST） in both peripheral blood and liver tissues were also measured. [Results]Compared to the control group,the level of amino acids in portal vein was significantly higher in high concentrate group goats,while the level of amino acids in hepatic vein was significantly decreased,and the storage of free amino acids in liver was also decreased. The p H value of rumen fluid declined and the goats were got subacute rumen acidosis（ SARA）,the content of LPS in peripheral blood was extremely significantly increased（ P〈 0.01）,the content of MDA increased while the enzyme activity ofSOD s

关 键 词：奶山羊 高精料 肝脏 AA重分配 

分 类 号：S827[农业科学—畜牧学]