The Investigating Of Cow Ketosis And The Relationship Between Cow Ketosis And Insulin Resistance

In this study, incidence of ketosis was investigated using ketone powers method and plasma beta-hydroxybutyrate (BHBA)concentration during early lactation, and researches for dairy cows ketosis were performed in energy balance, left displacementof abomasum, reproductive disorder, liver function, oxidative stress, insulin sensitivity and glucose tolerance. Aim of this study isto assess effect of ketone powers in detecting ketosis, investigate epidemiological status of keotsis, determine relationshipbetween insulin resistance and liver function, oxidative stress, and indicate a role of insulin resistance in keosis development,which provide a new pathogenesis, prevention and treatment in dairy cows ketosis.To understand occurrence characteristics of ketosis and its effects on productive performances and health, milk samples andblood samples from75cows were collected at14and21days postpartum in an intensive dairy farm in Heilongjiang province,China. Ketosis was screened by ketone powders and concentration of beta-hydroxybutyrate (BHBA), free fatty acid (NEFA) andglucose (Glc) in plasma of these cows was measured by biochemical analysis, and then milk yield (MY), left displacedabomasums (LDA), and days of pregnancy were investigated. Result showed that incidence of ketosis was41.33%in this farm.Detection of ketosis using ketone powers method had9.4%of false positive (misdiagnosis rate),3.9%of false negatives (missedrate),89.2%±2.4%of accuracy rate. MY at14days postpartum in ketosis group was significantly lower than healthy group (P<0.01), but MY at21days postpartum decrease non-significantly. Successful insemination time was longer in ketosis group thanin the healthy group. Ketosis group compared with healthy group, concentration of plasma Glc decreased significantly andconcentration of plasma NEFA and BHBA increased (P <0.01). Level of BHBA in plasma was more than1.2mmol/L at3to7days before left displaced abomasum occurred, which was significantly higher than healthy cows (P <0.01).To explore relationship between ketosis and insulin resistance during early lactation, in the same farm16ketosis (T) and24healthy control (C) cows were chosen for this study. Blood samples from all cows were collected at14days postpartum duringmorning fasting. Differences in energy balance, liver function, oxidative stress, insulin sensitivity and glucose tolerance wereanalyzed between T and C. Results displayed that cows with keosis were in condition of negative energy balance. T groupcompared to C group, level of plasma AST and DBIL raised significantly (P <0.01), and level of plasma TBIL also increasedsignificantly (P <0.05), but level of plasma CHE and TP decreased significantly (P <0.01and <0.05), and level of plasma ALT,IBIL, ALB, and GLO did not significantly changed, suggested that cows with ketosis suffered from certain degree of liverfunction abnormality. In addition, level of plasma malondialdehyde (MDA) and superoxide dismutase (SOD) was significantlyhigher in T group than in C group (P <0.05), implied that cows affected ketosis experienced oxidative stress. Furthermore, plasmaRQUICKI (full name) was lower significantly in T group than in C group (P <0.05), indicated that cows with ketosis had lowinsulin sensitivity. Concentration of plasma Glc in T group were higher than in C group during glucose tolerance test (P <0.05),and plasma Glc concentration was still4.24mmol/L at120min after intravenous injection of50%dextrose, which had asignificant differences between two groups (P=0.006), suggested that cows affected ketosis had insulin resistance.Conclusion obtained that a high incidence of ketosis occur in this farm. Ketone powers method should be widely used tomonitor quickly ketosis on the spot because it has low false-negative rate and high sensitivity and accuracy except for high falsepositive rate and low specificity. Cows with ketosis experience a negative energy balance during early lactation, have poor milkyield and pregnancy rate, and closed association with LDA. There is a closed relationship between someketosis and insulinresistance, which may be related to liver function and oxidative stress because both can cause insulin resistance.