Simplify the following text for a Grade 13 native English-speaking person.
Original: Due to the relatively lower level of proteins in vegetable matter , herbivore manure has a milder smell than the dung of carnivores or omnivores -- for example , elephant dung is practically odorless .
Simplified: Due to the relatively lower level of proteins in grasses , which herbivores eat , cattle manure has a milder smell than the dung of carnivores -- for example , elephant dung is practically odorless .