which one of this animals has the 1) shortest+ straightest small intestine? why ?

Question

RABBIT ,COUGAR ,SHEEP/DEER, MINK

Answer 1

the mink... it is likely due to the fact that they have short, active lifespans... they need a constant, high energy diet but can not eat too much in one sitting.. during evolution, it's likely that there was little to no energy invested in development of the digestive tract because of its short lifespan...

also, being a carnivore, they have no need for a cecum and long digestive tract (like rabbits, sheep, and deer) which is useful in extracting the low amounts of energy from plant material...

Answer 2

Probably the mink. Typical small intestine length depends on the diet type:
Carnivore, 3 to 6 times body length
Omnivore, 4 to 6 times body length
Herbivore, 10 to more than 12 times body length
(from the reference)
So we rate them as follows:
herbivorous 1-foot rabbit: about 12 feet
carnivorous 5- to 9-foot cougar: 15 to 54 feet
herbivorous 6-foot deer: about 72 feet
mostly but not exclusively carnivorous (therefore omnivorous) 1.5-foot mink: 6 to 9 feet.
Thus the deer has the longest small intestine, and the mink the shortest.