Although considered an invasive weed by some pond owners, duckweed can be quite beneficial if put to good use. One of the world's smallest flowering plants, duckweed may show up unbidden in ponds and lakes. But once it's there, duckweed helps to purify the water. It also is nutritious. When it is collected and dried, duckweed can be made into pellets and used as an inexpensive protein-rich food source for pigs, chickens and a variety of other livestock animals.
Collect duckweed in a porous container and allow it to drain for 5 to 10 minutes.
Put small amounts of duckweed in a shallow oven-safe container. According to biologists at Denison University, duckweed can be dried by baking it in an oven at 170 degrees Fahrenheit for 48 hours.
Spread duckweed over a large sheet of plastic and place it in direct sunlight. According to agronomists with Livestock Research for Rural Development, duckweed can be sun-dried. The amount of time this will take will depend on the temperature out doors (usually between 24 and 48 hours) so this is best done during the warm season.