Typically they don’t shoot animals in the head. Unless you are a dickhead who isn’t using the animals for meat.

It’s a waste to kill the baby male cows for no reason. You can slaughter for veal

Larger animals such as cows will probably be killed by a bolt gun or captive bolt, which is basically a piece of metal shooting into your brain and instantly killing you

Animals must be rendered surgically insensible before slaughter per USDA requirements

Other animals are rendered surgically through other mechanisms, including Electrical stunning, (note: the animal muscles may twitch due to electrical activity, so this “looks bad”) gas, and other mechanisms.

I highly recommend people look into Temple Grandin. She has several YouTube videos that highlight her work and some misconceptions.