Biochemical Indicators of Energy Balance in Blood and Other Secretions of Dairy Cattle: A Review

Negative energy balance condition during transition period is a gateway for production and infectious diseases during periparturient period. Energy balance is calculated directly through difference in energy input and energy output or indirect methods like estimation of energy metabolites (NEFA, BHBA and glucose level), Body condition scoring (BCS), back fat thickness, body weight and milk components (e.g., fat protein ratio), etc., at herd level. All the indirect energy balance indicators were studied in relation to postpartum health and performances in dairy animals. Blood biochemical parameters are routinely used for evaluation of general health status of animals. But, their relationship with energy balance in early lactating cows is not clear. In this review, effects of energy balance, critical period to assess the energy balance, and blood biochemical parameters in relation to energy balance, milk yield and health status of dairy animals are discussed. We also discussed energy balance indicators in other biological fluids in dairy cattle.