Basing the answer on a cow weighing 600kg, 1320 lbs:
half of that weight is removed in processing (at the slaughterhouse)
so we're down to 300kg 1160lbs
another third of that is bone and fat and cartilaginous materiel
down to 200kg 440lbs
Theoretically this weight could be used to make hamburgers, now given that many store bought burgers are about 85% beef that would give us around...
2024 1/4 pounder hamburgers per cow!
of course if you are talking about certain fast food outlet burgers they use more of the cow parts for their 100% beef hamburgers so you would get a different total again.