Researchers tested using fermented cow manure as fish feed in stagnant water ponds. Substituting 46% of fish pellets with fermented cow manure did not reduce total fish yield. Completely replacing pellets with cow manure led to a 47% decrease in fish yield, mainly affecting common carp growth. Tilapia were less impacted, while silver carp results were inconclusive. Adding sorghum grains improved common carp growth. Varying feed ratios affected fish yield consistency. Pond size may also influence fish yield.