Milk fever, known to fancy types as
parturient paresis, affects highly productive
dairy cattle, whose
calcium metabolism is seriously challenged by the volume of milk that they have been
bred to produce. When a "
downer"
cow cannot
resorb enough
mineral calcium from her bones for use in her milk, she experiences blood
hypocalcemia. Because calcium in an essential
ion for the transmission of
muscular, and some neural, electrical signals, this leads to general loss of muscle activity, including
weakness and inability to stand.
Source: Structure and Function of Domestic Animals, by Dr. Bruce Currie, and AnSci 150 by Dr. Ron Butler.