cattle are used to create inedible, poorer quality roughage feedstuff-- into a human consumable product- red meat.
roughages, typically are considered the cheapest source of nutrition for ruminating livestock-- as opposed to purchased or homegrown grains and concentrates.
If it were my project- I'd check into things such as rotational grazing- to max pastures- stockpiling forages for winter- to min use of hay- and maybe touch slightly on the use of co-by-or bi product feeds- to reduce inputs for grains and concentrates.