jpsdad not sure how to make those comparisons. It is a matter of energetics and you have to count energy expended. On feed trials on fish (not fish food) there is a huge difference as those that I have seen use live fish so the energy expended to capture is a negative. It is significant amount also. On fish food trials there is little to no energy output. I will find the study that provides that feeding can be between 4 -8 times more efficient in BG because there is no energy output.
Couple of threads
https://forums.pondboss.com/ubbthre...ds=energetics&Search=true#Post278746More from another thread - this is 2011 data and fish food and what we know about feeding has changed a lot since then.
natural food is better for fish over the long term
pellets (the right type) are 4 + times more efficient than natural food because the fish does not have to expend energy to catch it
lack of food is the single biggest limiting factor in fish growth and condition
From my presentation at PB IV � Fish Nutrition � Applied Science to Small Waters
Bioenergetics is the subject of a field of biochemistry that concerns energy flow and transformation through living systems.
Growth, development and metabolism are some of the central phenomena in the study of biological organisms. The role of energy is fundamental to such biological processes. The ability to harness energy from a variety of metabolic pathways is a property of all living organisms. Life is dependent on energy transformations; living organisms survive because of exchange of energy within and without.
Living organisms obtain energy from organic and inorganic materials. For example, lithotrophs can oxidize minerals . In photosynthesis, autotrophs can produce ATP using light energy. Heterotrophs (including fish) must consume organic compounds. These are mostly carbohydrates, fats, and proteins. The amount of energy actually obtained by the organism is lower than the amount present in the food; there are losses in digestion, metabolism, and thermogenesis.
Energy Budget ---- Inputs = Outputs + Growth
Because fish growth often is limited by food availability, supplemental feeding is a logical tool to improve the condition of fish in small impoundments as the energy cost for bluegill to feed on pellets is small relative to the high caloric intake, which can be 4-5 times greater than those fed natural foods (Schalles and Wissing 1976). Substantial increases in the standing stock of bluegill in ponds that receive pellet feed have been recorded (Schmittou 1969) and, in lakes, pellet feeding has been found to increase the number of large bluegills (Nail and Powell 1975).
These results indicate that total fish production and production of bluegill were each increased approximately 75 to 80% by supplemental feeding in 19 months after stocking (Schmittou 1967)
Previous studies demonstrated that feed in excess of 10 pounds per acre per day in bluegill ponds was not utilized. Some accumulated and decomposed, thus depleting the supply of dissolved oxygen which resulted in fish kills (Schmittou 1967) .
the rate of growth of sunfish can be increased by short-circuiting the food cycle, thereby producing harvestable size sunfish in a shorter period of time than would occur under natural conditions (Carnes 1966).
The pellet size should be approximately 20-30% of the size of the fish species mouth gape. Feeding too small a pellet results in inefficient feeding because more energy is used in finding and eating more pellets. Conversely, pellets that are too large will depress feeding and, in the extreme, cause choking. Select the largest sized feed the fish will actively eat. Addition of supplemental pelleted feed did not contribute to the rate of growth of young shad, but did increase the growth and spawning frequency of adults.
