| Ketosis is an important nutritional and metabolic disease during transition period in dairycow. According to the level of acetone body and clinical symptoms, ketosis is usually classifiedinto clinical ketosis and subclinical clinical ketosis. However, some reports suggested thatketosis may be classified into typeⅠketosis and typeⅡ ketosis based on the level of GLU,NEFA, and INs, like the classification of diabetes. TypeⅡ ketosis is rarely reported in China.Therefore, in this study, investigation were carried out in two intensive dairy farms inHeilongjiang province to clarify epidemiology features and the pathogenesis for typeⅡ ketosis.Itwill provide a scientific basis for preventing Type Ⅱ ketosis in the future.Firstly, to confirm the phenomenon of hyperglycemia in dairy cows affected ketosis. Bloodsamples from seventy-one cows were collected at14d and21d postpartum. According to plasmaBHBA concentration, all cows were divided into27ketotic cows (K) and22healthy controlcows (C). In K group,14cows affected ketosis at14d and21d postpartum were assigned to longterm group (LTK) and13cows affected ketosis at14d or21d postpartum were assigned to shortterm group (STK). After investigating energy metabolism and liver function status, resultsobtained that incidence of hyperglycemia in STK group was75%and60%at14d and21drespectively, but in LTK group both were28.57%. Levels of AST, TP, ALB and TBIL in LTKgroup were usually significantly higher than those in STK and C groups, and in STK weresignificantly higher than those in C, but levels of CHE and DBIL in LTK group was significantlylower than those in STK and C groups. These results demonstrated that hyperglycemia iscommon in dairy cows with ketosis and abnormal liver function in LTK cows was more seriousthan that in STK cows.Secondly, to find out the epidemiological characteristics of typeⅡ ketosis. Ninety-two cowswere randomly chosen from two intensive dairy farms, which thirty-nine of them were from farmA and fifty-three of them were from farm B. According to concentration of GLU, NEFA, andBHBA in plasma, all cows were divided into typeⅠketosis, typeⅡ ketosis and heathy cows.milk yield, parity, body condition score, and incidence were analyzed. Results showed that theincidence of ketosis in farm A was17.95%, of them was10.26%for typeⅠketosis and was7.69%for typeⅡ ketosis, respectively. The incidence of ketosis was64.15%in farm B, of them was28.30%for typeⅠketosis and35.84%for typeⅡ ketosis, respectively. The incidence ofketosis in farm B was highly significant (P<0.01) higher than that in farm A. The milk fielddecreased in two types of ketosis, but there is no difference between two farms. Cows with goodBCS are susceptible to TypeⅡ ketosis. These indicated that typeⅡ ketosis is common, but itsincidence is different in two farms.Again, to clarify the clinicopathological features of typeⅡ ketosis. Forty-six cows wereselected for blood samples at0day to28day. According to GLU, NEFA, and BHBA in plasma,all test cows were divided into typeⅠketosis, typeⅡ ketosis, and control group. Some liverfunctions parameters, oxidative stress parameters, and insulin resistance parameters weremeasured in all cows. Results showed that concentration of BHBA in two types of ketosis firstincreased and then decreased at0to28days after calving, reached the highest at21dpostpartum in typeⅠgroup and at7d postpartum in typeⅡ group. Concentration of GLU inplasma in three groups first decreased and then increased, reached the lowest at7d postpartumin typeⅠgroup and at14d postpartum in typeⅡ group, and was higher in typeⅡ ketosis thantypeⅠketosis or lower than C group. Concentration of NEFA in plasma first increased, declined,then increased in typeⅠgroup. Same changes occurred in typeⅡ group and reached the highestat7d postpartum. RQUICKI in typeⅡ ketosis was significantly lower than those in typeⅠgroupand C group. Activity of ALT and AST in plasma was significantly higher than those in C group,activity of MDA, NO in plasma in typeⅡ group was significantly higher than those in typeⅠketosis and in group C, activity of T-AOC in plasma in typeⅡ ketosis was significantly lowerthan those in typeⅠketosis. Therefore, cows with typeⅡ ketosis experienced insulin resistanceand oxidative stress.Finally, to study on relationship of insulin resistance with typeⅡ ketosis. In an intensivedairy farm,8cows affected ketosis at14day to21day postpartum, including four cows withgood body condition and four cows with normal body condition, and8healthy cows werecontrol group. According to cutoff point of glucose concentration at120min of glucose tolerancetest, all cows were divided into the abnormal glucose tolerance ketosis group (TH), the normalglucose tolerance ketosis (TL), and the healthy control group (C). liver function, oxidative stress,and insulin resistance were detected in all cows. Results showed that compared with othergroups, cows with TH had higher glucose concentrations in plasma, less values of RQUICKI, worse liver function, and more serious oxidative stress. These indicated that some cows withketosis associated with insulin resistance that may cause glucose utilization disorder, whileabnormal liver function and serious oxidative stress may contribute to insulin resistance.Conclusions obtained that typeⅡ ketosis is quite different from typeⅠketosis, which ischaracteristic by hyperglycemia, insulin resistance, and oxidative stress. TypeⅡ ketosis isclosely associated with insulin resistance due to abnormal liver and serious oxidative stress thatcause glucose utilization disorder. It lays the foundation for further revealing the pathogenesis oftypeⅡ ketosis and preventing typeⅡ ketosis in the future. |
PDF Full Text Request