Thats only part of the problem. If you swerve and don't hit it straight on, you are likely to hit someplace where the engine block doesn't give you as much padding. You car will be totaled and have a bad day if you hit a large buck head on. You and/or your passenger will be dead if it comes through the windshield or side window glass.
As I understand it, the purpose of ABS is to let you slam on your brakes and NOT swerve. If your wheels lock up then you lose all steering authority. ABS lets you slam your brake to the floor and still be able to keep your car on the road using the steering wheel. If your car doesn't have ABS, then you should know that and know to "pump your brakes" instead, to maintain control of the car.
If a child jumped in front of my car, I'd swerve even if that meant risking a tree. If I ran over a child I don't know that I'd be able to live with myself anyway, so the choice is clear: I risk myself to improve the odds of the child making it away unscathed. But a deer? No way in hell. I'll slam on the brakes, since my car has ABS, but I would not take my chances with swerving.
