Why herbivore produce less pepsin?

Herbivores produce less pepsin because their diets are primarily composed of plant material, which is high in cellulose and requires different digestive enzymes for breakdown. Unlike carnivores, which rely on pepsin to digest proteins from meat, herbivores have evolved specialized digestive systems, including longer intestines and microbial fermentation, to efficiently process plant fibers. Consequently, the need for pepsin is reduced, as their digestion relies more on cellulose-digesting enzymes produced by gut bacteria.