Feed
5.3 Alternative Diets
Alternative diets are a great option to utilize bulk products that are a byproduct of another production system, non-traditional ingredients, or even agriculture scraps. These diets would be prepared on- site and would still be combined in a ratio to meet both the nutrient requirements of the fish and the plant crop. One area where this is seen is in the brewing of craft beer or spirits. The spent grains from the fermentation process (brewer’s grains) typically have a protein content high enough to be used in combination with another protein component, again dependent on the crops to be grown.
· Kentucky State University5.2 Supplemental
A common question among small-scale and hobby aquaponic growers is if they can feed vegetable scraps, insects, or loose grains to their fish. These are known as supplemental diets and only meet part of the nutrient requirement of the fish. This is sometimes seen in traditional aquaculture practices in which fish are contained in large bodies of water where they can scavenge additional foods from the environment. Because aquaponics is a completely closed system, a complete diet must be fed.
· Kentucky State University5.1 Formulated
Formulated feeds are nutritionally complete pellets that are formulated for specific fish and life stage (Figure 15). Unlike other animal crops in agriculture, the nutritional needs of fish vary greatly among species for protein, fat, and carbohydrate inclusions. A carnivorous fish who eats at the top of its food chain, like a largemouth bass, requires a diet with high protein and low carbohydrates. On the other hand, omnivorous or herbivorous fish, like catfish or tilapia, require less protein and can tolerate higher levels of carbohydrate in their diets.
· Kentucky State University