Feed Formulations With few exceptions, feeding a
single type of food is neither
complete nor balanced and does
not supply all the nutrients a fish
might need in its diet. Hence, two
or more ingredients should be mixed into homemade, laboratory
and commercial feed formulations.
A diet may be formulated to
supplement natural foods already
available in the production system
or as a complete formulation when no other foods are provided. A
complete diet must be nutritionally
balanced, palatable, water stable,
and have the proper size and
texture. If natural foods are not
incorporated in ornamental fish diets, the feed must be
supplemented with natural or
synthetic pigments. The nutrient composition of
numerous feedstuffs can be found
in the literature and on the
Internet. Two books that deal
almost entirely with nutrient
composition of feedstuffs are 1) Handbook on Ingredients for
Aquaculture Feeds and 2) Standard
Methods for the Nutrition and
Feeding of Farmed Fish and
Shrimp. Another book, which is
available free on the Internet is United States-Canadian Tables of
Feed Composition, found at . Also,
available through the Internet is
the information provided by the
USDA Nutrient Data Laboratory at . Feeds are formulated to be dry,
with a final moisture content of
6-10%, semi-moist with 35-40%
water or wet with 50-70% water
content. Most feeds used in
intensive production systems or in home aquaria are commercially
produced as dry feeds. Dry feeds
may consist of simple loose
mixtures of dry ingredients, such
as “mash or meals,” to more
complex compressed pellets or granules. Pellets are often broken
into smaller sizes known as
crumbles. The pellets or granules
can be made by cooking with
steam or by extrusion. Depending
on the feeding requirements of the fish, pellets can be made to sink or
float. Flakes are another form of dry
food and a popular diet for
aquarium fishes. Flakes consist of a
complex mixture of ingredients,
including pigments. These are
made into a slurry which is cooked and rolled over drums heated by
steam. Semi-moist and wet feeds are
made from single or mixed
ingredients, such as trash fish or
cooked legumes, and can be
shaped into cakes or balls. Feed Preparation There is no single way for the
preparation of formulated fish
feeds, however, most methods
begin with the formation of a
dough-like mixture of ingredients.
Ingredients can be obtained from feed stores, grocery stores,
pharmacies, and specialty stores
such as natural food stores, as well
as from various companies that
may be found through the
internet. The dough is started with blends of
dry ingredients which are finely
ground and mixed. The dough is
then kneaded and water is added
to produce the desired consistency
for whatever fish is going to be fed. The same dough may be used
to feed several types of fish, such
as eels and small aquarium fish. Pelleting or rolling converts the
dough into pellets or flakes,
respectively. The amount of water,
pressure, friction, and heat greatly
affects pellet and flake quality. For
example, excess water in the mixture results in a soft pellet. Too
little moisture and the pellet will
crumble. Proteins and especially vitamins
are seriously affected by high
temperatures. Therefore, avoid
storing diet ingredients at
temperatures at or above 70° C
(158° F) and do not prepare dry feeds with water at temperature
higher than 92° C (198° F). Tools and Storage Procedures Making your own fish feed requires
few specialized tools. The tools are
used primarily for chopping,
weighing, measuring ingredients,
and for blending, forming and
drying the feed. Most of the utensils needed will
already be in the laboratory or
kitchen. Multipurpose kitchen
shears, hand graters, a paring
knife, a 5-inch serrated knife, a 6-
to 8-inch narrow-blade utility knife, and a 10-inch chef knife for
cutting, slicing, and peeling can be
used. A couple of plastic cutting
boards protect the counter and
facilitate handling the raw
ingredients. Heat resistant rubber spatulas, wooden and slotted
spoons, long-handled forks, and
tongs are very good for handling
and mixing ingredients. A basic
mortar and pestle, electric blender,
food processor or coffee grinder are very useful to chop or puree
ingredients; use grinder sieves and
mince die plates to produce the
smallest particle size possible. A
food mill and strainer such as a
colander or flour sifter help discard coarse material and obtain fine
food particles. For weighing and
measuring ingredients, dry and
liquid measuring cups and spoons,
and a food or laboratory bench
scale are required. Other utensils include plastic bowls (1½, 3, 5, and
8 quarts) for weighing and mixing
ingredients, a thermometer, and a
timer. A 3-quart saucepan and 10-
inch stockpot are good for heating
gelatins and cooking raw foods such as vegetables and starches.
The ingredients and blends may be
cooked in a small electric or gas
burner. A few trivets to put under
hot pans will protect counters and
table tops. Ingredients may be mixed by hand
using a rotary beater or wire
whisk, however, an electric mixer
or food processor is more efficient.
After mixing, a dough is formed
which can be fashioned into different shapes. A pasta maker, food or meat
grinder will extrude the dough into
noodles or “spaghetti” of
different diameters. As the noodles
emerge from the outside surface of
the die, they can be cut off with a knife to the desired length or
crumbled by hand, thus making
pellets. A potato ricer also serves
to extrude the dough into noodles
of the same size. For making flakes,
a traditional hand-cranked or electric pasta maker will press out
the dough into thin sheets. The pellets or thin sheets can be
placed on a cookie sheet and dried
in a household oven on low heat or
in a forced-air oven. A small food
dehydrator also performs the task
quite well. To add extra oil and/or pigments to pellets, a hand-held oil
atomizer or sprayer can is useful.
To separate pellets into different
sizes, a set of sieves (e.g., 0.5, 0.8,
1.0, 2.0 and 3.0 mm) is required. Freezer bags serve to store the
prepared feeds, and using a bag
vacuum sealer will greatly extend
the shelf-life of both ingredients
and the feed. The feed can be
stored double bagged in the freezer but should be discarded
after 6 months. Ideally, dried larval
feeds are not frozen but stored in
the refrigerator for no longer than
3 months. A finished diet, especially used for
experimental purposes, should be
analyzed for nutrient content
(proximate analysis: crude protein,
energy, moisture, etc.). In addition,
anyone intending to make his/her own fish feeds with unfamiliar
ingredients should have them
analyzed prior to their use. Sample Formulations and
Recipes There are numerous recipes for
making fish feeds, and it is beyond
the scope of this publication to
present them all. Presented here
are examples of a purified, a semi-
purified, and three practical diets that can easily be adapted to feed a
wide variety of fishes (Table 2). Purified and semi-purified diets are
used primarily in experimental
formulations to study the effects a
nutrient, such as the amount or
type of protein, may have on the
health and growth of fish. One simple formulation, which is
used traditionally to feed
ornamental fish in ponds, consists
of a mixture of 30% ground and
processed oats or wheat and 50%
of fish meal or pellets from a commercial manufacturer. By
weight, approximately 2-3% of fish
oil, and a 0.3% vitamin and a 1%
mineral premix are added to the
mixture. This mixture is blended
with water and can be formed into dough balls of different sizes.
call 08032861326 for consultancy
single type of food is neither
complete nor balanced and does
not supply all the nutrients a fish
might need in its diet. Hence, two
or more ingredients should be mixed into homemade, laboratory
and commercial feed formulations.
A diet may be formulated to
supplement natural foods already
available in the production system
or as a complete formulation when no other foods are provided. A
complete diet must be nutritionally
balanced, palatable, water stable,
and have the proper size and
texture. If natural foods are not
incorporated in ornamental fish diets, the feed must be
supplemented with natural or
synthetic pigments. The nutrient composition of
numerous feedstuffs can be found
in the literature and on the
Internet. Two books that deal
almost entirely with nutrient
composition of feedstuffs are 1) Handbook on Ingredients for
Aquaculture Feeds and 2) Standard
Methods for the Nutrition and
Feeding of Farmed Fish and
Shrimp. Another book, which is
available free on the Internet is United States-Canadian Tables of
Feed Composition, found at . Also,
available through the Internet is
the information provided by the
USDA Nutrient Data Laboratory at . Feeds are formulated to be dry,
with a final moisture content of
6-10%, semi-moist with 35-40%
water or wet with 50-70% water
content. Most feeds used in
intensive production systems or in home aquaria are commercially
produced as dry feeds. Dry feeds
may consist of simple loose
mixtures of dry ingredients, such
as “mash or meals,” to more
complex compressed pellets or granules. Pellets are often broken
into smaller sizes known as
crumbles. The pellets or granules
can be made by cooking with
steam or by extrusion. Depending
on the feeding requirements of the fish, pellets can be made to sink or
float. Flakes are another form of dry
food and a popular diet for
aquarium fishes. Flakes consist of a
complex mixture of ingredients,
including pigments. These are
made into a slurry which is cooked and rolled over drums heated by
steam. Semi-moist and wet feeds are
made from single or mixed
ingredients, such as trash fish or
cooked legumes, and can be
shaped into cakes or balls. Feed Preparation There is no single way for the
preparation of formulated fish
feeds, however, most methods
begin with the formation of a
dough-like mixture of ingredients.
Ingredients can be obtained from feed stores, grocery stores,
pharmacies, and specialty stores
such as natural food stores, as well
as from various companies that
may be found through the
internet. The dough is started with blends of
dry ingredients which are finely
ground and mixed. The dough is
then kneaded and water is added
to produce the desired consistency
for whatever fish is going to be fed. The same dough may be used
to feed several types of fish, such
as eels and small aquarium fish. Pelleting or rolling converts the
dough into pellets or flakes,
respectively. The amount of water,
pressure, friction, and heat greatly
affects pellet and flake quality. For
example, excess water in the mixture results in a soft pellet. Too
little moisture and the pellet will
crumble. Proteins and especially vitamins
are seriously affected by high
temperatures. Therefore, avoid
storing diet ingredients at
temperatures at or above 70° C
(158° F) and do not prepare dry feeds with water at temperature
higher than 92° C (198° F). Tools and Storage Procedures Making your own fish feed requires
few specialized tools. The tools are
used primarily for chopping,
weighing, measuring ingredients,
and for blending, forming and
drying the feed. Most of the utensils needed will
already be in the laboratory or
kitchen. Multipurpose kitchen
shears, hand graters, a paring
knife, a 5-inch serrated knife, a 6-
to 8-inch narrow-blade utility knife, and a 10-inch chef knife for
cutting, slicing, and peeling can be
used. A couple of plastic cutting
boards protect the counter and
facilitate handling the raw
ingredients. Heat resistant rubber spatulas, wooden and slotted
spoons, long-handled forks, and
tongs are very good for handling
and mixing ingredients. A basic
mortar and pestle, electric blender,
food processor or coffee grinder are very useful to chop or puree
ingredients; use grinder sieves and
mince die plates to produce the
smallest particle size possible. A
food mill and strainer such as a
colander or flour sifter help discard coarse material and obtain fine
food particles. For weighing and
measuring ingredients, dry and
liquid measuring cups and spoons,
and a food or laboratory bench
scale are required. Other utensils include plastic bowls (1½, 3, 5, and
8 quarts) for weighing and mixing
ingredients, a thermometer, and a
timer. A 3-quart saucepan and 10-
inch stockpot are good for heating
gelatins and cooking raw foods such as vegetables and starches.
The ingredients and blends may be
cooked in a small electric or gas
burner. A few trivets to put under
hot pans will protect counters and
table tops. Ingredients may be mixed by hand
using a rotary beater or wire
whisk, however, an electric mixer
or food processor is more efficient.
After mixing, a dough is formed
which can be fashioned into different shapes. A pasta maker, food or meat
grinder will extrude the dough into
noodles or “spaghetti” of
different diameters. As the noodles
emerge from the outside surface of
the die, they can be cut off with a knife to the desired length or
crumbled by hand, thus making
pellets. A potato ricer also serves
to extrude the dough into noodles
of the same size. For making flakes,
a traditional hand-cranked or electric pasta maker will press out
the dough into thin sheets. The pellets or thin sheets can be
placed on a cookie sheet and dried
in a household oven on low heat or
in a forced-air oven. A small food
dehydrator also performs the task
quite well. To add extra oil and/or pigments to pellets, a hand-held oil
atomizer or sprayer can is useful.
To separate pellets into different
sizes, a set of sieves (e.g., 0.5, 0.8,
1.0, 2.0 and 3.0 mm) is required. Freezer bags serve to store the
prepared feeds, and using a bag
vacuum sealer will greatly extend
the shelf-life of both ingredients
and the feed. The feed can be
stored double bagged in the freezer but should be discarded
after 6 months. Ideally, dried larval
feeds are not frozen but stored in
the refrigerator for no longer than
3 months. A finished diet, especially used for
experimental purposes, should be
analyzed for nutrient content
(proximate analysis: crude protein,
energy, moisture, etc.). In addition,
anyone intending to make his/her own fish feeds with unfamiliar
ingredients should have them
analyzed prior to their use. Sample Formulations and
Recipes There are numerous recipes for
making fish feeds, and it is beyond
the scope of this publication to
present them all. Presented here
are examples of a purified, a semi-
purified, and three practical diets that can easily be adapted to feed a
wide variety of fishes (Table 2). Purified and semi-purified diets are
used primarily in experimental
formulations to study the effects a
nutrient, such as the amount or
type of protein, may have on the
health and growth of fish. One simple formulation, which is
used traditionally to feed
ornamental fish in ponds, consists
of a mixture of 30% ground and
processed oats or wheat and 50%
of fish meal or pellets from a commercial manufacturer. By
weight, approximately 2-3% of fish
oil, and a 0.3% vitamin and a 1%
mineral premix are added to the
mixture. This mixture is blended
with water and can be formed into dough balls of different sizes.
call 08032861326 for consultancy
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