Agricultural subsidies that affect beef, either directly or indirectly, have been in place in the US for almost a century. So either your father is quite old, did not live in the US, or that meat was subsidized.
OK, but I'm asking for -how-, truly. My father is getting up there, but still raises cattle to this day. He buys them as calves, and sells them the next year. They mainly eat grass and hay, but admittedly there is -some- corn feed in the winter, which I understand as one source of subsidy, but I can't see it amounting to much in the grand scheme just based on the amount. When selling them, after accounting for initial cost, medicine, and extras, he breaks even. And that's at today's 'cheap' beef prices.
Industrial Carrie farming has additional costs. Like wise they need to be transported, butchered, packaged, etc. This adds cost.... Your dad's break even is still losing money for anyone doing this as a business.