[SauronOfMordor]

Domesticating cows, goats, and sheep allowed early humans to have something that would turn grass into nutritious milk. Initially, infants would have been fed milk, reducing infant mortality. Those who could tolerate cow’s milk into adulthood would survive better.

[Governor Dinwiddie]

That's an excellent point that didn't occur to me. Why of course! Humans can't really eat grass, but when you have a machine which turns grass into real food, then you've really got something there. Hail to the ruminants!