Inadequate bunk space in the breeding pen jeopardizes reproductive efficiency, according to a University of Wisconsin study.

During the study, researchers found inadequate bunk space to be one of the top factors linked to poor reproductive performance. They used a special technique to predict the percentage of cows pregnant at 150 days in milk. They found it decreased from 70 percent to 35 percent as bunk space decreased from about 24 inches to less than 12 inches.

“You’re welcome to overcrowd to get more milk, but this is the risk you run,” says Milo Wiltbank, professor of reproductive physiology at the University of Wisconsin. Aim for at least 18 inches of bunk space per cow in the breeding pen.