Lactating dairy cows must consume large quantities of dry matter (DM) to provide the nutrients needed to maintain high levels of milk production. The consequences of low dry matter intake (DMI) are lower peak milk yields, lower total milk production, excessive loss of body weight and poor reproductive performance. Research has shown a two pound increase in milk production for each pound increase in DMI. As milk production continues to increase, management of DMI becomes more critical.
"PB1598-Managing Intake of Lactating Dairy Cows," The University of Tennessee Agricultural Extension Service, PB1598-500-10/97 E12-2015-00-078-098, http://trace.tennessee.edu/utk_agexani/8