Yes. If the argument is about energy efficiency, I agree. Any system that is less than 100% efficient at turning calories into calories will result in, well, fewer calories.
However, we shouldn't assume health and diet are simply a matter of calories as input. Even conceding that beef isn't a particularly good choice for human health given it's saturated fat content, I don't know that replacing beef in the diet with corn would necessarily result in better health outcomes.
This assumes humans could turn 100% of the feed into usable calories. Considering 1) the link defines feed to include grazing and 2) humans are 0% efficient at turning cellulose into calories, the quoted number probably doesn't mean what you think it means.
Even if you’re just talking about biological calories rather than as a unit of energy, fire reduces energy expenditure to stay warm. Thus acting as a significant food supplement both historically and currently.
This is still a bit of a stretch to make a relevant point given the context of the discussion. I don’t think many are promoting getting rid of cattle to make room for biomass fuel.
US produces about 27 billion pounds of beef, roughly half of that weight comes from feedlots where they eat ~80% of feedlot calories comes from grains.
There's a bunch of numbers tossed around but it's something like 60-70 billion pounds of grain to get those 27 billion pounds of beef.
However, we shouldn't assume health and diet are simply a matter of calories as input. Even conceding that beef isn't a particularly good choice for human health given it's saturated fat content, I don't know that replacing beef in the diet with corn would necessarily result in better health outcomes.