亚急性瘤胃酸中毒耐受性不同的奶牛血浆和乳中脂肪酸及代谢物组成分析  

Analysis of plasma and milk fatty acid and metabolite composition in lactating dairy cows with differing tolerance to subacute ruminal acidosis

作　　者：张涛[1] 牟英玉 亓王盼 郭长征[1] 张继友 毛胜勇[1] ZHANG Tao;MU Ying-yu;QI Wang-pan;GUO Chang-zheng;ZHANG Ji-you;MAO Sheng-yong(Laboratory of Gastrointestinal Microbiology,Nanjing Agricultural University,Ruminant Nutrition and Feed Engineering Center,College of Animal Science and Technology,Nanjing Agricultural University,Nanjing 210095,China)

机构地区：[1]南京农业大学消化道微生物研究室,南京农业大学反刍动物营养与饲料工程中心,南京农业大学动物科技学院,江苏南京210095

出　　处：《草业学报》2021年第7期101-110,共10页Acta Prataculturae Sinica

基　　金：国家自然科学基金项目(32072755)资助。

摘　　要：为比较研究对亚急性瘤胃酸中毒(SARA)耐受性不同的奶牛血浆和乳中代谢组的差异,试验选用12头装有永久性瘤胃瘘管的泌乳中期荷斯坦奶牛[泌乳天数=(114±22)d],饲喂精粗比为4∶6的全混合日粮。在试验期第20和21天晨饲后0、2、4、6、8和12 h监测瘤胃pH值,在早晚饲喂前收集奶样,晨饲6 h后采集颈静脉血,用于测定脂肪酸及代谢物组成。基于奶牛瘤胃平均pH值高低,将奶牛分为SARA易感组(SUS,瘤胃pH=5.76,n=4)和SARA耐受组(TOL,瘤胃pH=6.10,n=4)。脂肪酸测定结果分析显示,与TOL组相比,SUS组奶牛血液及乳中的碳链长度≤C16的脂肪酸含量显著增高(P<0.05),而>C16的脂肪酸的含量显著降低(P<0.05),乳中饱和脂肪酸及单不饱和脂肪酸含量均显著降低(P<0.05)。血浆代谢组结果显示,SUS组奶牛血浆中L-苯丙酮酸水平显著降低(P<0.05),而MG(18:0/0:0/0:0)、9-HODE、12(13)Ep-9-KODE、烟酰胺、异戊基肉碱、磷酸肌酸和L-谷氨酸水平显著升高(P<0.05)。乳代谢组分析结果显示,与TOL组比较,SUS组奶牛乳中的1-硬脂酰磷酸甘油丝氨酸和鞘氨醇水平显著升高(P<0.05),而甘油磷酰基乙醇胺、3-磷酸甘油和乳清酸等其他14个差异代谢物水平显著降低(P<0.05),这些差异代谢物主要涉及甘油磷脂代谢、甘油脂代谢及泛酸与辅酶A代谢等代谢途径。综上所述,SARA耐受性不同的奶牛的血浆和乳中脂肪酸及代谢物组成存在较大差异,SUS组奶牛血浆中氨基酸代谢活动增加,乳腺的乳脂从头合成能力较强,而从血液中摄取长链脂肪酸能力减弱,与此同时,易感奶牛乳中磷脂、乳清酸等营养物质水平下降,乳品质下降。The present study aimed to explore the differences in plasma and milk metabolism of dairy cows with different subacute rumen acidosis(SARA)tolerance.Twelve fistulated Holstein dairy cows in mid lactation[days in milk=(114±22)d]were selected and fed the same diet consisting of 60%forage and 40%concentrate mixture.On days 20 and 21 of the trial period,the rumen pH was monitored at 0,2,4,6,8,and 12 h after morning feeding.Milk samples were collected before feeding in the morning and evening.Blood samples were collected from the jugular vein 6 h after morning feeding.All the milk and blood samples were stored in liquid nitrogen for subsequent fatty acid composition and metabolome analysis.Cows with the lowest and highest ruminal pH were assigned into the susceptible(SUS,n=4)and tolerant(TOL,n=4)groups,respectively.The fatty acid composition results showed that the proportions of≤C16 fatty acids in the blood and milk were significantly increased in the SUS group(P<0.05),while the proportions of>C16 fatty acids were significantly decreased(P<0.05).The levels of the saturated fatty acids(SFA)and monounsaturated fatty acids(MUFA)in the milk were significantly decreased in the SUS group(P<0.05).The LC-MS metabolomics results revealed that the L-phenylpyruvate was significantly reduced,while the levels of remaining MG(18:0/0:0/0:0),9-HODE,niacinamide,isovalerylcarnitine,phosphocreatine,L-glutamic acid,and 12(13)Ep-9-KODE were substantially increased in the SUS group.The results of milk metabolome analysis indicated that the levels of 1-stearoylphosphoglycerolserine and sphingosine were significantly increased,while the levels of 14 different metabolites were significantly decreased in the SUS group(P<0.05),including glyceryl-phosphoryl-ethanolamine,glycerol 3-phosphate,and orotic acid.These differential metabolites were mainly involved in glycerophospholipid metabolism(P<0.05),glycerolipid metabolism,and pantothenate and CoA biosynthesis.In conclusion,the fatty acids and metabolic profiles in the plasma and milk of cows

关 键 词：亚急性瘤胃酸中毒 耐受性 奶牛 脂肪酸 代谢组 

分 类 号：S858.23[农业科学—临床兽医学]