Duckling green poop after having plain cooked rice

[Tansias]

i was sick so could not go out and buy my ducklings feeds.so i was giving them cooked plain rice.But Whenever i give them cooked plain rice they have green poop.I gave them medicine and their poop became normal.But now again when i gave them cooked plain rice they are pooping green.My question is is their green poop because of plain cooked rice??Or there are serious problem?Now i can not go to any vets because they are not at this moment available where i am staying.
N.b i had given them plain cooked rice before and they were fine at first.and now i am giving them their feed

 

[sourland]

They need a complete and balanced diet for ducklings with adequate vitamins.