Characteristic Of Oxidative Stress In Ketotic Dairy Cows

Diary cows with ketosis in a condition of negative energe balance undergo a pathologic nutritional stress.Under stress state,The diseased diary cows could display a unbalance of oxidation and antioxidation,which could cause damage of tissue ang organ.Up to now,there are few information of oxidation stress in bovine ketosis.The objective of present experiment is to analyze indexes of oxidation and antioxidation in diary cow with ketosis and evaluate a correlation between oxidation stress and NEFA,BHBA.Ten diary cows each with clinical and subclinical ketosis and healthy were used to the experiment to determine the indexes of oxidation and antioxidation in blood.The results showed that compared with healthy cows,the milk yield and body condition score(BCS)in diary cows each with clinical and subclinical ketosis decreased significantly(p<0.05),NEFA and BHBA concentration increased significantly(p<0.01),and GLU reduced markedly,which accord with ketotic diagnostic standard.Compared with subclinical ketosis and healthy cows,ALT,AST activities in clinical ketosis increased significantly(p<0.01),concentration of TC?HDL?VLDL and LDLd decreased significantly(p<0.01),but there was no significant difference between subclinical ketosis and healthy cows.Other indexes did not showed a marked change.In the antioxiation indexes,SOD activity in clinical ketosis was lower than that of subclinical ketosis and healthy cows(P<0.01),but there was no significant difference between subclinical ketosis and healthy cows(p>0.05).CAT activity in clinical and subclinical ketosis was lower than that of healthy cows(P<0.05).The concentration of VC,VE and Inhibited hydroxyl radical capacity in clinical ketosis was lower that of subclinical ketosis and healthy cows(P<0.01 or P<0.05).Inoxidation indexes,MDA concentration in clinical and subclinical ketosis was higher than that of healthy cows(P<0.05);H2O2 and uric acid in ketotic cows were higher than those of subclinical ketosis and healthy cows,indicating that ketotic cows undergo oxidation stress.There are negative correlations between blood concentration of NEFA,BHBA and TC?HDL?VLDL?SOD?VC,VE,Inhibited hydroxyl radical capacity and uric acid(P<0.01)?There are positive correlations between blood concentration of NEFA,BHBA and ALT?AST ? LDH ? MDA(P<0.01),indicating that high levels of NEFA and BHBA in blood are associated with oxidation stress and fat deposition in liver in diary cows with ketosis.