| Ketosis in dairy cows is a kind of important nutritional and metabolic diseases during transitionperiod. It may seriously affect the cow health and farm profit, and impede the development of thedairy industry. In view of the serious dangers of cow ketosis, it is important to provide effectivecontrol measures for ketosis. This epidemiological study was conducted in two intensive dairyfarms in Heilongjiang province, and the effect of different doses of propylene glycol forpreventing ketosis was observed to lay the theoretical foundation for prevention of ketosis.In test one, the incidence study of dairy cow ketosis. The experimental cows14-21d postpartumwere randomly selected in the past three years in farm A and past two years in farm B, which hadthe similar age, body condition and parity,45cows in2012,31cows in2013, and45cows in2014in farm A respectively;30cows in2013,30cows in2014in farm B respectively.According to plasma BHBA, these cows were assigned to ketosis group and the control grouprespectively for investigation of epidemiology, lactation performance and reproductive traits&analysis of blood parameters(NEFA, GLU and AST, etc). Results showed that the incidences ofketosis in farm A were46.67%,16.13%, and20%in2012,2013, and2014, respectively; Thosein farm B were40.00%and23.33%in2013and2014. Activity of AST in plasma wassignificantly increased in ketosis group, and significantly positively correlated withketosis(R=0.432, P=0.006); Concentrations of Ca and P in plasma were significantly decreased(P<0.05), and significantly negatively correlated with ketosis(R=-0.603, P=0.024; R=-0.592,P=0.049). Milk yield60-90d postpartum in ketosis group was significantly lower than that in thehealthy group(P<0.05). First estrus days, insemination number, breeding days and calvinginterval were significantly increased in ketosis group(P<0.05) and was significantly positivecorrelation between plasma BHBA levels(R=0.338, P=0.029; R=0.306, P=0.049; R=0.423,P=0.011; R=0.360, P=0.021), and a significant correlation between ketosis and laminitis. ProfitLoss of a cow with ketosis14-21d postpartum was4.59RMB per day.In test two, preventive effect of propylene glycol on dairy cow ketosis. Forty-five cows wererandomly selected at an intensive dairy farm in Heilongjiang Province, which had similar age,body condition and parity, then divided into two experimental groups (I and II) and one controlgroup,15cows per group. The cows in group I were drenched into500mL propylene glycol, 300mL in group II, and not in C group0,1and2days after calving once a day. Results showed:group I and II compared with C group, thirteen days after drug administration, plasma BHBAcontent was very significantly decreased,8days later, GLU content was markedly increased,NEFA, AST content were significantly decreased; The incidence of ketosis was verysignificantly reduced, insemination numbers, first breeding days and breeding days weredecreased significantly (P<0.05). Group I compared with group II, the incidence of ketosis wasvery significantly reduced (P<0.01). Economic benefits of three groups was analyzed throughdecision tree, under this experimental conditions,500mL propylene glycol perfusion90dayspostpartum got the most net profit, whose difference reached5.31RMB.Conclusion obtained that there was the higher incidence of ketosis in high-yielding dairy farm,the abnormal liver function, the lower lactation performance and the poor reproductiveperformance in dairy cows with ketosis, which may cause serious economic loss. Propyleneglycol could reduce the incidence of ketosis, improve reproductive performance. Under thisexperimental condition,500mL propylene glycol per cow may earn the best economic benefitdue to milk yield.
|
PDF Full Text Request