I raised cattle (Black Angus steer) for about 10 years for the purpose of providing custom beef. We took them from a neighboring ranch at around 600 lb calves, and raised them until slaughter in late January, generally topping out at about 1300 lbs (on the hoof).
They were pasture raised, with supplemental alfalfa hay at around 35-50 lbs per day as the grass dried out in mid-summer. Starting in late August, about 5lbs of apples, and 15-20 lbs of rolled corn was added. (Rolled corn is produced by steaming the kernels, then rolling on steel rollers. The rolled corn provides greater digestive time in the rumen (and therefore more caloric absorption) as opposed to cracked corn which is excreted more rapidly.) These were not feedlot cattle; they were range/pasture raised and fed abundantly.
The more corn they ate, the “sweeter” the flavor became, and it was also very evident in the fat marbling. We sold, for personal consumption, as whole, 1/2 and 1/4s, every ounce we raised.