why do humans need to eat many different kind of foods to get their vitamins etc but large animals like cows only need grass to survive?

Question

why do humans need to eat many different kind of foods to get their vitamins etc but large animals like cows only need grass to survive?

In: Biology

Answer 1

Others have explained it well, but another fact about many animals that we think of as herbivores(cows, deer, squirrels) will commonly eat meat if it’s available! Cows and deer have both been seen munching on baby birds in low nests, as well as chewing on bones from carcasses