And cows are fed all sorts of garbage. Its all done because of money. Give dairy cows a few pounds of expired candy and the lactose in their milk for the day increases making it sweeter. Give meat cattle a majority grain diet for the last few months of their lives and there will be more fat in their meat, it also gives them stomach ulcers. Probably why they can't have a straight grain diet for more than a few months, as it would affect the health of the animal to the point that it would lower the weight of the animal before processing, costing somebody money.

That static 70% statistic looks bad, but like, once a crop is finished growing it starts to rot unless processed into something that has a shelf life.

So if I can grow a plot of feed corn, twice a year to supplementally feed to an animal that gets most of its food from just browsing grass and other greenery, that I won't turn into food for 1.5 to 2 years. That seems like a pretty efficient way of storing food calories. Additionally cattle/sheep/goats mow the grasslands down, transport seeds around the areas they graze, fertilize as they move, and their hooves disturb the soil to help dropped seeds make better soil contact. And chickens can lay eggs, increasing their usefulness as a source of food.

I mean, a can of corn on a shelf stops being useful until its turned back into calories, right.

I could argue that the 70% statistic means that the entire world's population is being fed from the other 30% of crops grown directly for human consumption. Which doesn't include the % of that 30% that gets trashed before being consumed.

And pastures' being "planted" usually just means seed being spread. Not really that big of a deal. Seed doesn't need to be spread after the grass is established.