Cows that Eat Juniper Risk Losing Calves

Cows that eat bark, berries or branches from western juniper trees late in pregnancy are more likely to abort their calves or give birth early according to Oregon State University research.

Oregon State University Livestock and Range Extension Agent Cory Parsons says that similar to ponderosa pine needles, western juniper contains toxins that constrict the flow of oxygen to the fetus in the third trimester of a cow’s pregnancy.

Parsons: “The management considerations on western juniper would be the same as it would be for a typical Pacific Northwest rancher would do managing his beef cattle around ponderosa pine. Limit access during that third gestation of pregnancy, make sure that they are meeting nutrient requirements. Be aware of cold spells like we have right now or winter storms events that come through and deposit a lot of snow limiting availability of those cattle to access if its winter feed that they are out on or native pastures. Or if they are in an animal confinement feeding operation on conserved forages, making sure their nutrient requirements are being met and that their intake requirements are met.”

Parsons says that western juniper can be found throughout the Pacific Northwest and while it is a native plant, it has become more encroaching and is outcompeting sagebrush and other native grasses on rangelands.