fish nutrition, the basics - san diego tropical...
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Fish Nutrition, The Basics What We Put in our Fish and Why
Paul A. Curtis, AquaSolver LLC
2255 Seaquest Trail, Escondido, CA, 92029 760-518-8170, www.aquasolver.com
For The: San Diego Tropical Fish Society
August 10, 2014
Why is Nutrition Important
• Hardiness • Growth • Normal Development, WSB Juvenile • Gamete Quality, WSB Brood • Disease Resistance, β-Glucans • Life and Death During Development
What We Feed
• Dry Prepared Diets • Flake, Pellets, Home Made
What We Feed
• Live Feeds • Rotifers, Artemia, Copepods
What We Feed
• Frozen Thawed feeds • Sardines, Mackerel, Squid, Shrimp, Brine Shrimp
Live Foods
• Mostly used in larval rearing • Larvae will eat a dry diet buy not
metabolized • What do live food provide
• Nutrition • Gut enzymes • Gut bacteria
• What live foods used by you?
Types of Live Foods
• Paramecia • Rotifers, 225µm • Brine Shrimp, 450 µm • Moina • Daphnia • Copepods (predacious?)
Paramecium
Rotifer
Brine Shrimp Nauplii
Brine Shrimp Cyst Harvest
Moina and Daphnia
Live Food Enrichment
• Why Enrich? • Live foods can be nutrient limiting • Bolster nutrient value of feed, HUFA’s • Life or Death to marine larvae !
• Enrich With What? • Fats, Proteins and Vitamins • Many commercial products
Brine Shrimp Hatch and Enrichment Procedure
• Hatch 24 hrs at 28ºC and 20-30 ppt • 12 hours after hatch begin feeding and can
start to enrich • Some “Directions” have enrichment after
hatch, no-no
Ads and Disads of Live Feeds
• Ads. • Fish like them • Necessary • Can enrich to suit
• Disads. • Expensive • Labor intensive • Can be nutrient limiting • Can be unreliable
Frozen Thawed Foods
• Use Sardines, Squid, Anchovies, Mackerel • Can be deficient in vitamins due to freezing
damage degradation • Can supplement with tablets or other
supplements • Hubbs solution! Injections.
Prepared Diet Production Methods and Feeding
• Types of Production Methods • Steam Pelleted • Extruded • Expanded • Flaked • Other, gelatin, sausage etc.
Steam Pelleting
• Made With Steam (100° to 180° for 35 sec) and Little Pressure
• Binders make ingredients stick together • One of oldest methods of pelleting • Grinding and blending of ingredients • Forced through a die after heating • Pellets cut to length • Blown dry to 8% - 10% moisture
Steam Pelleting Ads
• Less loss of vitamins and other nutrients • Low energy to make • Initial less cost • Smaller mills available for on site
manufacture
Steam Pelleting Disads.
• Less digestible diets • Large amount of fines • Sinking feeds only • Lower feed conversion • Large minimum pellet size (2.4 mm) • Most fat is 20% in diet • Not as durable in warm water
Extruded Diets
• High Pressure and Heat (300°) Applied • Mash placed an barrel of machine and water added • High heat, pressure and friction applied • Starch gelatinized as binder • Forced through die with less pressure on other side
so expands • Air introduced to control buoyancy • Moisture 10-15% so dried to 10% • Screened to remove fines and fat added to reduce
dust and increase fat level
Extruded Diets Ads.• Expansion controlled so buoyancy controlled • Can have fat levels higher than 20% • High temps increase nutrient availability and
increases feed conversions • Better digestibility less waste • Carbohydrate is binder so no fillers needed • Structural integrity allows for smaller pellet size • No fines, durable pellet and uniform size • No sharp edges
Extruded Diets Disads.• Degradation of vitamins, medications and other
nutrients can be high • Higher manufacturing costs • Cost of shipping more as pellet density is less
Flaked Feeds
• Mostly aquarium feeds • Very finely crushed and made into slurry • Made into thin film on screen, baked and
made into flakes • Formulations often quite different than
commercial fish diets
What is Important for Proper Nutrition
• Protein • Fat • Carbohydrate • Ash • Vitamins • Minerals • Moisture • Energy
Tested with Proximate Analysis and is on label.
Bomb Calorimeter
Bomb Calorimeter
Drying Oven
Energy
• All fish require base energy content • All fat, protein and carbohydrates have
energy and varies with digestibility of ingredient
• Energy needed for digestion • Fish have variable use for different
ingredients, eg. Cellulose vs fish protein
Protein
• Most expensive component • Building Blocks for growth, Amino Acids • Key Ingredient in Diets • Affect palatability and Performance • Quality and Quantity Important
• Plant and Animal meals
• Usually included at 25%-50% • ~22 amino acids and 10 are Essential
Essential Amino Acids
• Arginine • Histidine • Isoleucine • Leucine • Lysine
• Methionine (Cystine) • Phenyalanine (Tyrosine) • Threonine • Tryptophane • Valine
Can’t Be Synthesized, Must get from diet
Deficiencies of Essentials
• Methionine • Cataracts
• Tryptophane • Scoliosis, Fin erosion
• Lysine • Fin Erosion, Mortality
Where Do We Get It From? Protein
!• Fish Meal Best, Most Common Source
Various Sources and Fish Commodity, Capelin, Anchovy, Herring Peru, Mexico, Canada producers Produced how?
• Plant and Other Animal Sources • Rendered feather and Blood meals • Corn and Soybean • Not as good a source, less digestible
Lipids (Fats)
• Inexpensive, Source cost varies • Type of fat important • HUFA’s most important
• Larvae, life or death
• Type and amount often customized • High energy salmonids, high HUFA larval
• Usually 10%-25% in diets
Fatty Acids
• Saturated FA • No double bonds in chain
• Unsaturated FA • At least one double bond
• Polyunsaturated FA • More than one double bond • HUFA’s included in this group
PUFA’s Essential
• Three most important groups are • Omega 3 (ω3), Linolenic acids • Omega 6 (ω6), Linoleic acids • Omega 9 (ω9), Olenic acids
• Essential Groups • ω3 are primary essential fatty acids • Most common deficiency of DHA and EPA
• Docosahexanoic acid, DHA, 22:6 n-3 • Eicosapentanoic acid, EPA, 20:5 n-3
Sources of Lipid for Diets• Fish Oil, Best source • Beef Tallow, mostly saturated • Corn oil • Canola oil
Deficiency, Total and Essentials• Increased disease incidence • Unexplained Mortality
Carbohydrates
• Not essential and very cheap • Many fish can not utilize well and excess can
cause disorders • Some species makes a good energy source • Sugars, Wheat (cellulose), Starch, other
grains • Not a component of the natural diet • Usually at around 12%-25% in diets
Ash
• Non digestible component of diet • Mostly bone from fish meal and other
minerals • Level usually 9% in diet
Moisture
• Amount of water in diet • Can vary from feed to feed and
manufacturer • Usually around 8%-10%
• Soft-Moist around 15%
• Higher moisture, faster degradation
Vitamins• Most important to balance in diet • 2 Groups
• Water Soluble – C, B’s, inositol, choline – Short retention time, leaching
• Fat Soluble – A, E, D, K – Long retention time, storage
• E and C antioxidants protect fats • Required amount vary between vitamins
Many Deficiencies Associated with Vitamin Deficiencies
• Fat Soluble !• A: exophthalmia, edema, eye lesions, ascites • D: tetany, lipoid liver, calcium imbalance • E: depigmentation, ascites, muscular dystrophy • K: prolonged clotting, anemia, hemorrhagic gills
and eyes
• Water Soluble !• B1 Thiamine: nervous disorder, Loss Equilib,
Convulsions, hyperirritability
• B2 Riboflavin: lethargy, dark skin, spinal def., photophobia
• B3 Niacin: skin fin gut lesions, photosensitivity, sunburn, ascites
• B4 Pantothenic acid: clubbed gills, distended opercula
• B5 Pyridoxine: nervous disorders, convulsions, spiral swimming
• B12: reduced growth, anemia
• Water Soluble (cont.) !• C Ascorbic Acid: intramuscular hemorrhaging,
distorted gills, spinal deformaties, ascites, impaired healing, increase infections
• Biotin: degenerative gills, skin lesions, muscle atrophy, convulsions
• Folic Acid: lethargy, slow growth, dark, anemia • Choline: fatty liver, exophthalmia, distended
abdomen, hemorrhagic gut and kidney • Inositol: dark, distended abdomen, fin erosion
Minerals
• Macro and Micro Minerals • Some are essential though in small
quantities • Many toxic but required in small amounts • Fish can absorb many from water • Seawater contains many minerals
Major Requirement
• Calcium • Phosphorous (essential for growth) • Magnesium • Sodium • Potassium • Chlorine (chloride) • Sulfur
Trace Minerals• Iron • Copper • Zinc • Manganese • Selenium • Iodine • Cobalt • Fluorine
• Molybdenum • Aluminum • Nickel • Vanadium • Silicon • Tin • Chromium • Etc…….
Mineral Deficiencies
• Calcium and phosphorous: poor growth, bone development impaired
• Magnesium: poor growth, anorexia, lethargy, flaccid muscles, increased mortality
• Iron: anemia • Selenium: decreased growth, muscle dystrophy
Mineral Deficiencies cont.
• Copper: growth depression, anemia • Iodine: goiter, thyroid dysfunction • Zinc: decreased growth • Manganese: decreased growth, abnormal tail
growth, spinal fusion
Diet Formulation
• Very species specific • Ingredients and vitamin requirements very
specific to species and age • Biology of animal will generally dictate need
Carp and Tilapia
• Long Guts, Grazers • Can digest more difficult to digest
ingredients; starch cellulose • Digest plant proteins better • High cellulose and less protein • Cheap diets
Catfish• Moderate gut length, Scroungers and
predators • Can utilize some plant protein • Can use low protein feeds if fed to satiation;
grower 24-28%, Fry 50%, fingerling 35% • Cheap feeds
Salmon and Trout
• Short guts, Pisciverous • Can not utilize plant proteins • Need 45% protein and 15% fat • Do not use carbohydrates well • Energy from protein and fat • Expensive diets
Other Feed Concerns
• Storage should not exceed 75° • Should last 6 months, dry diet, Moist diets
less; Vit E and C • Fat rancidity • Vitamin degradation
• Type of diet for age and stage of development • Fry vs. fingerling vs. grower vs. finishing
Broodstock Feeding
• Your eggs are only as good as your brood feed
• Brood are often overlooked and thus produce poor quality eggs
Feeding First Feeds, Dry
• Feed sizes vs. size of fish • Salmon, trout and catfish eat dry first feeding
• Marine fish need live feeds • Weaning to dry feed is goal in hatchery
• Why wean; improved growth and efficiency • Wet vs. Dry
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