Managing Energy Balance During the Transition Period

The period immediately prior to and following calving, is associated with extensive biological and logistical adaptations. During this time frame, cows and heifers must adjust to the physical and biological transition from pregnancy to lactation as well as environmental changes such as new rations (ingredient and energy density alterations) and pen relocation. In addition, cows in this transition phase characteristically secrete more energy (fat, protein and lactose) in their milk than they consume via the diet. As a consequence, animals experience a substantial negative energy balance (NEBAL), which is associated with an increased risk of metabolic disorders and health problems (milk fever, ketosis, fatty liver, displaced abomasums, etc.) as well as reduced reproductive performance (days to first service, conception rates, etc.). For decades the primary management method utilized to alleviate the magnitude of NEBAL was feeding additional energy in the form of either grains or fats. Unfortunately, the incidence and magnitude of NEBAL continues to be the primary issue surrounding transition period failures. Transition period failures are economically costly for producers. A decrease in milk yield combined with an increase in health care, labor and animal replacement costs can reduce or even eliminate potential net income. Recent research at The University of Arizona indicates that energy balance parameters can be improved during the transition period providing producers with a potential management tool to reduce transition period failures and consequently increase profits.