Effects of Prepartum Dietary Carbohydrate Source on Metabolism and Performance of Primiparous Holstein Cows During the Periparturient Period (Report‪)‬

INTRODUCTION The periparturient period of dairy cows typically is defined as 3 wk before to 3 wk after parturition (Grummer, 1995). It is characterized by changes in the endocrine, metabolic, and immunological status from pregnancy to lactation. Requirements for glucose and metabolizable energy increase two- to threefold during the periparturient period (Drackley et al., 2001). In addition, the requirement for calcium increases approximately fourfold on the day of parturition (Horst et al., 1997). During this period, particularly the last week of gestation, dry matter intake (DMI) dramatically declines (20-40%) and slowly increases after parturition (Hayirli and Grummer, 2004). Metabolic disorders and health problems are common during this time and can easily erase the entire profit potential for an individual cow in lactation.