Prolonged cool, wet weather can cause more stress on cows than a zero-degree day that is sunny and dry in January. Critical stress can start at 59 F if the cow has a wet hair coat and has not yet grown her full heavy winter coat, says Don Spiers, livestock physiologist at the University of Missouri. Under these types of conditions, you need to up the energy in the cows’ diets to prevent loss of body condition as they go into winter.
“We’re setting up conditions to see a lot of weak-calf syndrome next spring,” says David Patterson, MU extension beef reproduction specialist. “Cows in lowered body-condition scores have more difficulty at calving time.”
Normally, spring-calving cows that are gestating during the winter can thrive on stockpiled pastures, possibly supplemented with hay, until they calve in the spring. Sometimes a grain ration supplement is needed just before calving so the cow will produce plenty of milk for the newborn calf.
“This year, the cows may need a little supplement each day, starting earlier than usual,” Dr. Patterson says. “It is easier and cheaper to maintain body condition than it is to try to put it back on just before calving.”