x1 is cud/cecotrope/re-eaten food for x2 (ruminant/rabbit) that began as x3
This is any food that is eaten multiple times by the same creature. E.g. cecotropes eaten by rabbits are also xrudja since they're (usually) eaten again by the same rabbit. However, this is not the food a mother bird provides her young since it is not eaten by the same creature. «se xrudja» can mean "to ruminate"