Dietary energy requirements of a mature beef cow, in total megacalories (Mcal) of net energy for maintenance (NEm) per day. Values are expressed as the average daily amount required during each month after calving and were calculated for a 1,400-pound (635-kg) cow that has a gestation length of 283 days, gives birth to a live 85-pound (39-kg) calf once per calendar year, has a peak milk production of 18 pounds (8.2 kg) of milk per day, raises the calf through weaning at ~7 months old, and is managed under a plane of nutrition such that dietary protein does not limit the animal’s use of energy provided by the diet.
Courtesy of Dr. Jason Smith.