Prevalence of Ketosis and its Correlation with Lactation Stage, Parity and Peak of Milk Yield in Iran
Ketosis is a metabolic disorder which usually occurs in cows during early lactation in both, industrialized and developing countries. There are no data available about the prevalence of ketosis in major dairy producing provinces in Iran. This study investigated the prevalence of ketosis among 1,400 and 3,000 mmol L-1 were considered as subclinical ketosis (SCK) and clinical ketosis, respectively. The prevalence of SCK and clinical ketosis during second (42.4%) and third weeks (24.8%) post calving. The ketosis prevalence was found significant between regions but not parity. Prevalence of ketosis was higher in Gorgan, Shahrekord and Sari than the other regions. The negative correlations between prevalence of ketosis (BHBA= 1400 mmol l-1) and blood glucose concentration and lactation stage were significant. In addition, the positive correlation between blood glucose concentration and lactation stage was also significant. Blood glucose and BHBA concentrations were not correlated with the parity stage. The meant milk production for cows suffering from clinical ketosis, SCK and healthy cows were 28,35 and 45 kg day-1, respectively. Significant negative correlation coefficients were found between blood BHBA with peak milk yield. In conclusion, the present results show that the best times to indentify clinical and SCK are 14 and 17 days after calving.