Johnson, Sterling K.

Texas A&M University

L-l018
Oral Administration of Antibiotics to Fishes
Sterling K. Johnson*
Treating fishes with antibiotics as part of their
diet has become a common practice in the fish
culture industry. Oral administration of antibiotics
has been a successful corrective measure in cases
where light kills caused by bacterial invasion begin
to occur. Several antibiotics have widespread use
in fish culture, but only one (Terramycin) has been
cleared by the Food and Drug Administration for
use on warm water fishes destined for human
consumption. Other clearances probably can be
expected with the maturity of research in the fish
disease field.
In certain areas, commercially prepared fish
feeds with antibiotic additives are available. Use
of this type of product has convenience and in
many cases is more economical than feeds with
self-applied antibiotics.
A farmer may decide, however, that the "do it
yourself" approach would be the better choice for
his particular needs.
SUGGESTED METHOD
FOR PREPARING COATED FEEDS
Thoroughly mix the correct amount of pow-
dered antibiotic in oil. Fold the oil-antibiotic
mixture into the daily pellet allotment. Stir gently
until the pellets are uniformly coated. Cod liver
oil seems to have a more appealing taste to fishes
than does vegetable oil. The proper amount of
oil to use is that which will provide a thin film
of coating around the pelleted fish food.
Dosage
Recommended dosages of antibiotics usually
are expressed as weight of drug per weight of fish
per day. For example, they are expressed as grams
per 100 pounds of fish per day or milligrams per
kilogram of fish per day. When figuring the dosage
of antibiotic only the weight of the active ingre-
dient (the antibiotic) of the purchased formulation
should be considered. The weight of fishes can
be estimated by sampling fishes to get an esti-
mated average length and then comparing the
length to a length-weight table. Table 1 is modi-
fied from Swingle and Shell (Auburn University,
Agricultural Experiment Station. 1971. Circular
183) and is based on wild fish popUlations. Culti-
vated fish might be expected to run slightly heavier
in weight.
Table 2 gives the amount of antibiotic in grams
that is to be added to one pound of feed at various
dosage rates and feeding rates. From Tables 1 and
2, one may establish the amount of antibiotic that
will be used per day during a treatment.
Example: A pond has therein an estimated
10,000 channel catfish fingerlings that average 5
inches in length. The feeding rate of these fishes
is 3 percent of body weight per day. The dosage
of antibiotic has been suggested to be 4.5 grams
of antibiotic per 100 pounds of fish per day. How
much antibiotic should be used?
First, by using Table 1, determine how many
pounds of fish are present:
A 5-inch fingerling averages 16.1 grams so 10,000
would represent 16.1 X 10,000 = 161,000 grams.
In pounds this would be 161,000 grams 454
grams/ pound = 355 pounds of fish.
Table 1. length-weight relationships of channel catfish
A A
Inches W/(gm.) Inches W/(gm.)
2Y, 2.1 9Y, 105.6
3 3.5 10 123.3
3Y, 5.6 11 170.2
4 1.4 12 228.4
4Y, 11.4 13 296.3
5 16.1 14 380.5
5Y, 21.4 15 476.0
6 27.2 16 587.1
6Y, 34.7 17 720.6
7 43.3 18 867.6
7'12 53.3 19 1,041.4
8 63.8 20 1,230.1
8Y, 76.5 21 1,441.4
9 90.9 22 1,686.7
A
W = computed weight; based on fishes from several river
systems.
Table 2. Amount of antibiotic in grams added to 1 pound of feed
Percent of Dosage in grams of antibiotic per 100 pounds of fish per daybody weight
fed per day 1.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 6.0 8.0 10.0
1 % ................ 1.00 2.00 2.50 3.00 3.50 4.00 4.50 5.00 6.00 8.00 10.00
2% ....----.- ... -. 0.50 1.00 1.25 1.50 1.75 2.00 2.25 2.50 3.00 4.00 5.00
3%. 0.33 0.67 0.83 1.00 1.14 1.33 1.50 1.66 2.00 2.66 3.33
·Extension fish disease specialist, Texas A&M Universit. 37.3
Texas A&M University • Agricultural Extension Service • John E. Hutchison, Director • College Station
Table 3. Cost of drugs required to treat 1,000 pounds of fish for 1 day·
Cost per gram of drug used
Rate of dosage
(grams per 100 pounds 0.5 1 2 3 4 5 10 20
of fish per day) cent cent cents cents cents cents cents cents
0.5 ______ ......____....... $ 0.025 $ 0.05 $ 0.10 $ 0.15 $ 0.20 $ 0.25 $ 0.50 $ 1.00
1.0_____ ...... ___ .... ___ ..
.05 .10 .20 .30 .40 .50 1.00 2.00
2.0 __ .___________________
.10 .20 .40 .60 .80 1.00 2.00 4.00
3.0 ___ .. _. ________ . __ .__
.15 .30 .60 .90 1.20 1.50 3.00 6.00
4.0_.... __ .______ ._. _____
.20 .40 .80 1.20 1.60 2.00 4.00 8.00
5.0. __ .. _
.- -- ... --_. .25 .50 1.00 1.50 2.00 2.50 5.00 10.00
6.0 ... _. _____________ ... _.
.30 .60 1.20 1.80 2.40 3.00 6.00 12.00
7.0 __ . __
-.. --
.35 .70 1.40 2.10 2.80 3.50 . 7.00 14.00
8.0 _____
._- ---------
.40 .80 1.60 2.40 3.20 4.00 8.00 16.00
10.0. __ ._. __ .____________
.50 1.00 2.00 3.00 4.00 5.00 10.00 20.00
30 40 SO 60 70 80 90
cents cents cents cents cents cents cents
0.5 ---_ ..--------------------------------.-_ ... $ 1.50 $ 2.00 $ 2.50 $ 3.00 $ 3.50 $ 4.00 $ 4.50
1.0 _._ .. ____________.. ______ .___________ .. ______ 3.00 4.00 5.00 6.00 7.00 8.00 9.00
2.0 _. _______ ._________ . ___ ..._.. ______________ 6.00 8.00 10.00 12.00 14.00 16.00 18.00
3.0_______ ._____________ .. _. ___ .. _____ .____ ...... 9.00 12.00 15.00 18.00 21.00 24.00 27.00
4.0 _.. __ . ____ ... ___ ._. __________________________ 12.00 16.00 20.00 24.00 28.00 32.00 36.00
5.0 _. ___________________________ .... __ . _________ 15.00 20.00 25.00 30.00 35.00 40.00 45.00
6.0 ___________ .____________ .. ___ . ______ ._ .. ____ 18.00 24.00 30.00 36.00 42.00 48.00 54.00
7.0 ______ .... _._. ____________ .__ ._______________ . 21.00 28.00 35.00 42.00 49.00 56.00 63.00
8.0 ______ ._._._. ______ ....... ____ .___________ .. __ 24.00 32.00 40.00 48.00 56.00 64.00 72.00
10.0. ____ ._. ___ . _____________ .. _. __ .. ____________ 30.00 40.00 50.00 60.00 70.00 80.00 90.00
*Modified from Piper and Wolf (1959) Progressive Fish-Culturist 21(3):135-137.
Fish fed at 3 percent of the body weight would
be fed 355 X .03 = 10.65 pounds. From Table 2
we find that at a 3 percent feeding rate and a dos-
age rate of 4.5 grams per 100 pounds of fish per
day the amount of grams that should be added to
one pound of feed is 1.50.
Now to answer the question on how much anti-
biotic should be added to the feed that is fed each
day:
10.65 pounds of feed X 1.5 grams/pound of
feed = 16 grams.
The 16 grams is the weight of the active in-
gredient that is required but the weight of the
total formulation that is to be added must be de-
rived. A 10 percent active ingredient preparation
would be added to the feed in an amount of 160
grams.
Cost
Consideration should be given to whether or
not the cost of antibiotic treatment is economical.
Table 3 provides information based on a fish crop
of 1,000 pounds and will aid in the derivation of
drug cost.
Example: How much will it cost to treat 4,000
pounds of fish for 10 days when the cost of the
drug is 2 cents per gram and the suggested dosage
is 4.0 grams per 100 pounds of fish per day?
Consulting Table 3, we find that at a dosage
rate of 4.0 grams per 100 pounds of fish per day
and at a cost of 2 cents per gram, it will cost 80
cents to treat 1,000 pounds of fish for one day.
But there are 4,000 pounds of fish to be treated for
a period of 10 days.
Calculating: 80 cents X 10 X 4 = $32.00 =
cost of treatment.
Unrestrained use of antibiotics as precaution-
ary measures may reduce greatly the expected
margin of profit. No evidence is available that
shows that feeding antibiotics will enhance growth
of fishes in a manner experienced for other cul-
tured animals.
Many antibiotics are available in technical
grades such as poultry or veterinary-type formu-
lations. The drugs should be purchased as such
since there is a' considerable difference in cost
compared to the highly-purified and expensive
product for human use.
Conversions
454 grams == 1 pound == 0.454 kilogram
28.35 grams == 1 ounce == 0.0625 pound
1 gram == 1000 milligrams == 0.001 kilogram
Cooperative Extension Work in Agriculture and Home Economics, Texas A&M University and the United States Department of
Agriculture cooperating. Distributed in furtherance of the Acts of Congress of May 8, 1914, as amended, and June 30, 1914.
10M-9-71 WM·2


English

Oral Administration of Antibiotics to Fishes.

Texas A&amp;M Repository

L-l018Oral Administration of Antibiotics to FishesSterling K. Johnson*Treating fishes with antibiotics as part of theirdiet has become a common practice in the fishculture industry. Oral administration of antibioticshas been a successful corrective measure in caseswhere light kills caused by bacterial invasion beginto occur. Several antibiotics have widespread usein fish culture, but only one (Terramycin) has beencleared by the Food and Drug Administration foruse on warm water fishes destined for humanconsumption. Other clearances probably can beexpected with the maturity of research in the fishdisease field.In certain areas, commercially prepared fishfeeds with antibiotic additives are available. Useof this type of product has convenience and inmany cases is more economical than feeds withself-applied antibiotics.A farmer may decide, however, that the "do ityourself" approach would be the better choice forhis particular needs.SUGGESTED METHODFOR PREPARING COATED FEEDSThoroughly mix the correct amount of pow-dered antibiotic in oil. Fold the oil-antibioticmixture into the daily pellet allotment. Stir gentlyuntil the pellets are uniformly coated. Cod liveroil seems to have a more appealing taste to fishesthan does vegetable oil. The proper amount ofoil to use is that which will provide a thin filmof coating around the pelleted fish food.DosageRecommended dosages of antibiotics usuallyare expressed as weight of drug per weight of fishper day. For example, they are expressed as gramsper 100 pounds of fish per day or milligrams perkilogram of fish per day. When figuring the dosageof antibiotic only the weight of the active ingre-dient (the antibiotic) of the purchased formulationshould be considered. The weight of fishes canbe estimated by sampling fishes to get an esti-mated average length and then comparing thelength to a length-weight table. Table 1 is modi-fied from Swingle and Shell (Auburn University,Agricultural Experiment Station. 1971. Circular183) and is based on wild fish popUlations. Culti-vated fish might be expected to run slightly heavierin weight.Table 2 gives the amount of antibiotic in gramsthat is to be added to one pound of feed at variousdosage rates and feeding rates. From Tables 1 and2, one may establish the amount of antibiotic thatwill be used per day during a treatment.Example: A pond has therein an estimated10,000 channel catfish fingerlings that average 5inches in length. The feeding rate of these fishesis 3 percent of body weight per day. The dosageof antibiotic has been suggested to be 4.5 gramsof antibiotic per 100 pounds of fish per day. Howmuch antibiotic should be used?First, by using Table 1, determine how manypounds of fish are present:A 5-inch fingerling averages 16.1 grams so 10,000would represent 16.1 X 10,000 = 161,000 grams.In pounds this would be 161,000 grams 454grams/ pound = 355 pounds of fish.Table 1. length-weight relationships of channel catfishA AInches W/(gm.) Inches W/(gm.)2Y, 2.1 9Y, 105.63 3.5 10 123.33Y, 5.6 11 170.24 1.4 12 228.44Y, 11.4 13 296.35 16.1 14 380.55Y, 21.4 15 476.06 27.2 16 587.16Y, 34.7 17 720.67 43.3 18 867.67'12 53.3 19 1,041.48 63.8 20 1,230.18Y, 76.5 21 1,441.49 90.9 22 1,686.7AW = computed weight; based on fishes from several riversystems.Table 2. Amount of antibiotic in grams added to 1 pound of feedPercent of Dosage in grams of antibiotic per 100 pounds of fish per daybody weightfed per day 1.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 6.0 8.0 10.01 % ................ 1.00 2.00 2.50 3.00 3.50 4.00 4.50 5.00 6.00 8.00 10.002% ....----.- ... -. 0.50 1.00 1.25 1.50 1.75 2.00 2.25 2.50 3.00 4.00 5.003%. 0.33 0.67 0.83 1.00 1.14 1.33 1.50 1.66 2.00 2.66 3.33·Extension fish disease specialist, Texas A&M Universit. 37.3Texas A&M University • Agricultural Extension Service • John E. Hutchison, Director • College StationTable 3. Cost of drugs required to treat 1,000 pounds of fish for 1 day·Cost per gram of drug usedRate of dosage(grams per 100 pounds 0.5 1 2 3 4 5 10 20of fish per day) cent cent cents cents cents cents cents cents0.5 ______ ......____....... $ 0.025 $ 0.05 $ 0.10 $ 0.15 $ 0.20 $ 0.25 $ 0.50 $ 1.001.0_____ ...... ___ .... ___ ...05 .10 .20 .30 .40 .50 1.00 2.002.0 __ .___________________.10 .20 .40 .60 .80 1.00 2.00 4.003.0 ___ .. _. ________ . __ .__.15 .30 .60 .90 1.20 1.50 3.00 6.004.0_.... __ .______ ._. _____.20 .40 .80 1.20 1.60 2.00 4.00 8.005.0. __ .. _.- -- ... --_. .25 .50 1.00 1.50 2.00 2.50 5.00 10.006.0 ... _. _____________ ... _..30 .60 1.20 1.80 2.40 3.00 6.00 12.007.0 __ . __-.. --.35 .70 1.40 2.10 2.80 3.50 . 7.00 14.008.0 _____._- ---------.40 .80 1.60 2.40 3.20 4.00 8.00 16.0010.0. __ ._. __ .____________.50 1.00 2.00 3.00 4.00 5.00 10.00 20.0030 40 SO 60 70 80 90cents cents cents cents cents cents cents0.5 ---_ ..--------------------------------.-_ ... $ 1.50 $ 2.00 $ 2.50 $ 3.00 $ 3.50 $ 4.00 $ 4.501.0 _._ .. ____________.. ______ .___________ .. ______ 3.00 4.00 5.00 6.00 7.00 8.00 9.002.0 _. _______ ._________ . ___ ..._.. ______________ 6.00 8.00 10.00 12.00 14.00 16.00 18.003.0_______ ._____________ .. _. ___ .. _____ .____ ...... 9.00 12.00 15.00 18.00 21.00 24.00 27.004.0 _.. __ . ____ ... ___ ._. __________________________ 12.00 16.00 20.00 24.00 28.00 32.00 36.005.0 _. ___________________________ .... __ . _________ 15.00 20.00 25.00 30.00 35.00 40.00 45.006.0 ___________ .____________ .. ___ . ______ ._ .. ____ 18.00 24.00 30.00 36.00 42.00 48.00 54.007.0 ______ .... _._. ____________ .__ ._______________ . 21.00 28.00 35.00 42.00 49.00 56.00 63.008.0 ______ ._._._. ______ ....... ____ .___________ .. __ 24.00 32.00 40.00 48.00 56.00 64.00 72.0010.0. ____ ._. ___ . _____________ .. _. __ .. ____________ 30.00 40.00 50.00 60.00 70.00 80.00 90.00*Modified from Piper and Wolf (1959) Progressive Fish-Culturist 21(3):135-137.Fish fed at 3 percent of the body weight wouldbe fed 355 X .03 = 10.65 pounds. From Table 2we find that at a 3 percent feeding rate and a dos-age rate of 4.5 grams per 100 pounds of fish perday the amount of grams that should be added toone pound of feed is 1.50.Now to answer the question on how much anti-biotic should be added to the feed that is fed eachday:10.65 pounds of feed X 1.5 grams/pound offeed = 16 grams.The 16 grams is the weight of the active in-gredient that is required but the weight of thetotal formulation that is to be added must be de-rived. A 10 percent active ingredient preparationwould be added to the feed in an amount of 160grams.CostConsideration should be given to whether ornot the cost of antibiotic treatment is economical.Table 3 provides information based on a fish cropof 1,000 pounds and will aid in the derivation ofdrug cost.Example: How much will it cost to treat 4,000pounds of fish for 10 days when the cost of thedrug is 2 cents per gram and the suggested dosageis 4.0 grams per 100 pounds of fish per day?Consulting Table 3, we find that at a dosagerate of 4.0 grams per 100 pounds of fish per dayand at a cost of 2 cents per gram, it will cost 80cents to treat 1,000 pounds of fish for one day.But there are 4,000 pounds of fish to be treated fora period of 10 days.Calculating: 80 cents X 10 X 4 = $32.00 =cost of treatment.Unrestrained use of antibiotics as precaution-ary measures may reduce greatly the expectedmargin of profit. No evidence is available thatshows that feeding antibiotics will enhance growthof fishes in a manner experienced for other cul-tured animals.Many antibiotics are available in technicalgrades such as poultry or veterinary-type formu-lations. The drugs should be purchased as suchsince there is a' considerable difference in costcompared to the highly-purified and expensiveproduct for human use.Conversions454 grams == 1 pound == 0.454 kilogram28.35 grams == 1 ounce == 0.0625 pound1 gram == 1000 milligrams == 0.001 kilogramCooperative Extension Work in Agriculture and Home Economics, Texas A&M University and the United States Department ofAgriculture cooperating. Distributed in furtherance of the Acts of Congress of May 8, 1914, as amended, and June 30, 1914.10M-9-71 WM·2

https://oaktrust.library.tamu.edu/bitstream/1969.1/165072/2/1018/Leaf1018.pdf

Oral Administration of Antibiotics to Fishes.

Abstract

Similar works

Full text

Available Versions

Texas A&M University

Texas A&M Repository

Oral Administration of Antibiotics to Fishes.

Abstract

Similar works

Full text

Available Versions

Texas A&M University

Texas A&amp;M Repository

Texas A&M Repository