The simple answer is to consider a guard or bumper. However, which one you get depends on what kind of land you are driving through. If you drive across areas with plenty of large animals, it is best to avoid braking suddenly or trying to swerve with a large vehicle. If you have used a deer guard in the past, but have run into a cow, horse, or moose, you've probably had to pay a great deal for a new bumper or truck repairs.
If you drive across land with deer and smaller wildlife, a deer guard will suffice. But to keep you and your truck safe from locations with horses, cows, and moose, you should consider a larger bumper, such as the moose bumper.