The length of the small intestine differs in various animals depending on the food that they eat. The small intestine is longer in herbivores than in carnivores because herbivores consume plant and grass-based food which is full of cellulose and the digestion of cellulose takes a long time. Whereas, carnivores are unable to digest cellulose due to the lack of an appropriate enzyme to break beta acetal linkages in cellulose. Deer is a herbivore and a tiger is a carnivore. So, the length of the small intestine in deer is more as compared to the length of the small intestine of tiger.