Ask the Vet

Protective Instincts

Cow behavior after calving is often based on the need to protect offspring from predators. (DTN/Progressive Farmer photo by Jim Patrico)


Why do cows eat the placenta from their newborn calves? I have been told they have to have it, but sometimes I find them lying in the pasture.


I think this is a protective mechanism to avoid attracting predators during that vulnerable period right around birth. Many animals, including dogs and cats, will eat their placentas.

Many benefits have been claimed from the practice. The placenta does contain high levels of hormones, iron, B vitamins and endorphins (the body's natural pain relievers). However, I can find little solid scientific evidence to support these claimed benefits. I did find reports of cows choking on placentas in my research, but I have never personally seen or heard of this.