Animals????

I Dont No I have A Cat.

Probably has something to do with the size of the animal and thus proportionally the size of their innards - horse and cow are big animals they make BIG patties/apples/whatever term you want to call their poo. Point is they make a lot it.

size of the animals, the stomachs, like a cow has more than 1 and i raise horses and theres arent always large you want them too it also depends on the food they eat!

Remember that cows have four chamber stomachs which means their intestines are bigger. Every animal has different size intestines and they all eat different foods and the food digests according to the kinds of food that they eat and it passes according to the size of their intestines and colon.

sheep hav smaller stomachs, cows food passes through four compartments n thye drink mor water n horses hav large stomachs

Not sure, but the cow fertilizer is pretty consistent.

I don't know the answer but my guess is that originally they where not kept in fields and they ate whatever was around, it has only been the last 1000 years that humans have kept cattle and so on, and that's a very small time in the evolutionary scale. ....................................just a guess

I find it awkward that you pay attention to animal's poop, but here is an answer:

How they digest, and what percentage of the nutrients they use.

size of the stomach and speed of digestion.

Ummm, genes? You are not what you eat, but what your genes tells you.