ABSTRACTFeeding trials were conducted withMacrobrachium rosenbergiito evaluate corn silage as a nutrient source for prawns in the pond environment. Cages were placed in a commercial pond and stocked with juvenile prawns at a density of 10 animals/m2. Cage bottoms were buried in the pond mud, allowing animals access to the detrital layer. Diets of commercial prawn pellet, corn silage, and a 50:50 pellet and silage mix were fed at rates of 2.5% and 5% (dry weight basis) biomass per day. Control cages received no applied feed. Diets were isocaloric and growth was measured as weight gain. During the 10‐week trials, animals receiving the commercial pellet and the 50:50 diet grew similarly at the 5% feeding rate but not when fed at 2.5%. Positive contribution of silage in the 50:50 diet fed at 5% is suggested By the facts that when fed at 2.5%, pellet alone was insufficient to promote growth equal to that on pellet fed at 5%, and silage alone produced more growth than non‐fed controls. Survival in cages averaged 95% for the fed treatments (90–100%), 89% for the non‐fed controls (88–90%). Data suggest that high fiber feeds such as corn silage can play a role in supporting the pond production of prawns and that the cage technique can be a useful tool in assessing prawn feeds in a pond en