The Role Of Methylglyoxal In Herd Monitoring Of Ketosis In Periparturient Dairy Cows

Ketosis in periparturient dairy cows,mainly known as a disease at herd level,causes severe economic losses to the dairy industry.Herd monitoring and early warning are of principal significance to the prevention of ketosis,but has so far rarely been applied using a scientifically sound evaluation system.Methylglyoxal(MGO),a reactive ?-oxaldehyde,play an important role in diabetes and its complications is considered a biomarker of disease progression.Ketosis and diabetes have many common characteristics,such as hyperlipidemia,insulin resistance.However,it remains unclear whether the ketosis of dairy cows produce MGO inblood and play a role in metabolism.To study the metabolic characteristics of periparturient dairy cows were determined the relative indexes of carbohydrate,lipid and mineral elements in serum,and nutrition and lactational performance which contradistinction between the ketotic cows and heathy cows,which can provide the experimental basis for herd monitoring and early warning of ketosis.The function of MGO on ketosis was studied by detecting the content of MGO in serum of cows.By detecting serum concentrations on perinatal cows with ketosis,the concentrations of BHBA,NEFA and AST in serum were gradually increased from-2 weeks(before delivery),reaching the highest levels +1 week(after delivery),and then restoration;GLU,Ca,K and P were gradually reduced starting from-2 weeks,reaching the lowest levels +1 week,and then gradually recovering to the original levels.Besides,the levels of GLU,Mg and K,and BCS for prepartu cows were significantly positively correlated with postpartum;referring to NEFA,during early lactation(+14 d),it and MF and F/P were significant positive correlation,while it and MP were negatively correlated;furthermore,as for GLU,there was a significant negative correlation between it and DM,EE,CF,NDF,ADF and MUN in daily rations,and positive correlation between it and GE;concerning BCS,it and MF?ML and TS were positively correlated,being negatively correlated between it and DM?EE?CF?NDF and ADF in daily rations;and there was a significantly positive correlation between the days of milk production and BHBA and NEFA(+1 week).Comparing with healthy cows,during early lactation,concentrations of BHBAand NEFA noticeably increased,so did the F/P,while MP considerably decreased of cows with ketosis.Moreover,serum concentrations of MGO in ketosis cows remarkably exceed heifer cows and healthy cows.Comparing with heifer cows,GLU,FA,TG,K,P and Mg were significantly decreased,while DHAP,NEFA,BHBA,AST,TBIL and Hp were significantly increased.There was a significant negative correlation between NEFA and GLU,FA,K,P and Mg,and positive correlation with AST,TBIL,Hp and DHAP in experimental cows;BHBA was negatively correlated with GLU,FA,TG,Mg and K,but positively correlated with AST,TBIL,Hp and DHAP.referring to MGO,it and GLU,FA,TG,K,P and Mg had significant negative correlation while positive correlation with BHBA,NEFA,AST,TBIL,Hp and DHAP.MGO was negatively correlated with GLU and FA,but had significantly positive correlation with BHBA,NEFA,TG,Hp and P in lactating cows.Conclusion: The concentrations of BHBA and NEFA in serum are the major indexes for monitoring ketosis in early lactation.We initially confirmed some sensitive indexes for diagnosing ketosis and herd monitoring,such as GLU,AST,BCS,MF,MP and F/P.The increase in the production of MGO in serum of ketosis cows may be due to the production of ketone bodies produced by lipid metabolism and glycerol phosphate.Hence,MGO can be used as a demonstration marker in the development of ketosis.