Given the size of the elephant, it is not surprising that elephants need to eat a substantial amount of food for maintenance. In fact, elephants can consume between 1.5-2% of their body weight in just 12 hours, varying on the time of year 16.
Since we have calculated the metabolizable energy of the East Indian Kino and Cormandel Ebony and we know what the DEE is of the Asian elephant is, we can calculate how much of these respective plants the Asian elephant can eat.
East Indian Kino
The metabolizable energy of this plant was 372 kcal/kg and the DEE was calculated as 381,666.4 kcal/day for a female weighing 2750 kg.
38,166.4 kcal/day / (372 kcal/kg) = 102.6 kg/day
Therefore, the elephant would have to eat 102.6 kg of East Indian Kino per day to meet energy requirements. This comes out to 3.7% of the female elephants body weight a day, which falls within the expected range of the elephant eating 3-4% of her body weight in 24 hours.
If we assumed that the East Indian Kino weighs 3 g, we could calculate how many leaves the elephant would have to eat to meet energy requirements.
102.6 kg/day / (0.003 kg)= 34, 200 leaves
That’s ALOT of leaves! Luckily, because the elephant eats so many different plant species, it can pick plants that are even more nutritious then the East Indian Kino. It would be highly unlikely that they would consume only one plant type.
The metabolizable energy of Cormandel Ebony was calculated to be 143.3 kcal/kg. This has considerably less metabolizable energy than the East Indian Kino, so we expect the elephant would need to eat much more of it to meet its energy requirements.
38,166.4 kcal/day / (143.3 kcal/kg) = 266.4 kg/day
It is difficult to calculate how much Cormandel Ebony would be eaten because Asian elephants consume the roots of this tree.
( Asian Elephant, Jagdeep Rajput, http://www.arkive.org)