A pond is a complex system, but the principles under which a pond operates are quite simple. In fact, most pond owners are able to quickly understand the important principles, most importantly the cycle of pond life and the food chain. In a catfish pond, the sun provides energy to grow microscopic plants (plankton), tiny animals feed on the plankton, bigger animals feed on those animals and then the big fish eat them. Knowing all the inputs and potential outcomes allows individuals to implement pond management techniques to achiever their goals.
In a pasture, the sun shines on the plants, the plants convert the solar energy into food and the cattle eat the plants. The farmer manages soil chemistry and fertilizes to increase the growth of pasture plants so more cattle can be grown. In the same way, the production of fish is increased if water chemistry is adjusted and fertilizers added to increase growth of the tiny plants that are the first step in the food chain. The farmer can further increase production by using prepared cattle feeds to supplement the natural productivity of the pasture. Likewise, feeding commercial pelleted feeds can increase fish production.
The main difference between raising cattle and raising fish is, of course, the water. Producing a fish-eating predator like largemouth bass just adds another link to the food chain. The sun grows the microscopic plants, tiny animals eat those plants, those animals are eaten by small fish and those fish are eaten by the bass. Once again, the whole chain depends on plenty of sunshine and nutrients.
The addition of the extra link in the chain means that more animals are involved and that the system is a bit more complicated, so a bit more care is needed to make sure that the energy from the sun goes through channels that produce food for bass and not into pathways that might produce less desirable results, like lots of snails or tiny bream. Insuring that the food gets to the bass is the result of stocking the right species, manipulating the pond environment and harvesting the right fish at the right time. Pond and fish management can be complicated, but if you stayed focused you can take your fishing pond from okay to great.