Can cows go past their due date?

“They usually go a few days past the due date and tend to be a little bigger,” Westphal explains. Actual due date can vary depending on gestation length of certain individuals. Some cows consistently tend to calve earlier or later than their projected due date.

How long before calving will a heifer bag up?

Bagging Up

Cows that are preparing to give birth often exhibit prominent udders that appear packed with milk. This “bagging up” process often takes place weeks before cows are due to give birth. For some cows, however, it can happen within the span of one day prior to parturition.