BACKGROUND: Metabolic profiles have been used in efforts to predict pre parturient problems and fertility, to diagnose metabolic diseases, and to assess nutritional status in dairy cows. These profiles may help to confirm the diagnosis of sub clinical diseases, to be aware of possible causes of infertility in the herds, or to monitor improvement in herd animals. OBJECTIVES: This study investigated changes in the metabolic profile of high producing Holstein dairy cows from early lactation to close-up dry periods. The results of the current research can provide useful guidelines for management strategies during different physiological phases of high producing Holstein dairy cows.
METHODS: Twenty five multiparous high producing Holstein dairy cows were selected from a high producing industrial dairy farm. Cattle were divided into 5 equal groups of early, mid and late lactation and far-off and close-up dry cows. Blood samples were collected from all cows and sera were separated to evaluate glucose, insulin, ك-hydroxybutyric acid [BHBA] , non-esterified fatty acid [NEFA] , cholesterol, triglyceride [TG] , high, low and very low density lipoproteins [HDL-cholesterol, LDL-cholesterol and VLDL-cholesterol] . CONCLUSIONS: The results of the present study show that metabolic biomarkers change in high producing Holstein dairy cows, under different physiological states. These changes are induced commonly by negative energy balance, lactogenesis and fetal growth in each state.