NUTRIENTS AND FEEDING[objectives]

• Explain how animals and plants vary in the acquisition of nutrients

• Discuss the nutrient requirements of aquaculture species

• Explain how nutrient requirements are met during culture

• Describe kinds and sources of feed• Identify and evaluate approaches in feeding• Discuss buying and storing feed

NUTRIENTS & FEEDINGChapter 5

Nutrient – a substance used by organisms to live and grow.

Food – any material ingested that contains needed nutrients.

Ingest – consume or eat food.

TROPHIC LEVELS

Producer (Autotroph)– plants, algae, and cyanobacteria make their food by photosynthesis.

Consumer (Heterotroph) – must consume other organisms.

*herbivore – eats plants only *carnivore – eats meat only *omnivore – eats both plants and meat *detritivore – eats decaying plant/animal matter.Decomposer – (bacteria/fungi) have external

digestion.

PRODUCERScyanobacteria

PRODUCERSalgae

PRODUCERSplants

CONSUMERSherbivores

CONSUMERScarnivores

CONSUMERSomnivores

CONSUMERSdetritivore

DECOMPOSERS

MAJOR NUTRIENTS

• Proteins – made from amino acids; necessary for tissue growth and repair.

• Fats – made from fatty acids; necessary for cell membranes and energy.

• Carbohydrates – made from saccharides; necessary for energy.

• Vitamins – water soluable and fat soluable; necessary for enzymes.

• Minerals – inorganic earth materials; necessary for coenzymes.

MEETING NUTRIENT NEEDS

• Promote natural food growth – fertilizer

• Culture food materials – brine shrimp and aquaponic lettuce

• Capture food materials – copepods for snapper and cobia

• Provide manufactured feed – floating or sinking fish feed

FERTILIZER

CULTURE FOOD MATERIALS

CAPTURE FOOD MATERIALS

PROVIDE MANUFACTURED FEED

MANUFACTURE OF FEED

• Ingredients – corn, soybean meal, meat/bone meal, blood meal, fish meal.

• Life-stage feeds – larval, starter, grower, broodstock.

• Bouyancy – floating feed contains more air; can observe animals.

• Particle preparation – meals and pellets.

FEEDING APPROACHES

• Scheduled feeding – provided at specific time (ex. Redclaw crawfish before dark)

• Juveniles need to feed more frequently than older animals.

• Free-access feeding – making food available all the time by using automatic feeders.

BUYING AND STORING FEED

• Small producers usually buy feed in 50-pound bags.

• Large producers usually buy feed in bulk.• When storing feed avoid the following: *insect infestation *rodent damage and contamination *spoilage or rancidity *contact with water *chemical contamination