Studies on quantity of trace elements in the formulated diets for the young eel Anguilla japonica-III. Suitable level of zinc supplementation to the formulated diets in young eel


Park, C Won; Shimizu, C

Nippon Suisan Gakkaishi 55(12): 2137-2141

1989


Nippon
Suisan
Gakkaishi
55(12),
2137-2141
(1989)
Suitable
Level
of
Zinc
Supplementation
to
the
Formulated
Diets
in
Young
Eel*"
2
Chul
Won
Park*"
and
Chiaki
Shimizu*s
(Received
June
15,
1989)
This
study
was
conducted
to
determine
the
effect
of
supplementation
of
Zn
to
fish
meal
diets
on
growth
of
Japanese
eel.
The
feeding
experiments
were
carried
out
using
white
fish
meal
diets
supplemented
with
0,
50,
100,
and
200
pg/g
of
Zn
as
Zinc
sulfate
(ZnS0e
anhydrous).
The
results
revealed
that
the
fish
on
diet
annexed
with
50
and
100
pg/g
of
Zn
were
observed
to
have
the
high
growth
among
these
groups.
Eel
fed
a
diet
without
supplementation
of
Zn
caused
a
high
value
:of
condition
factor
(19,0)
and
the
content
of
Zn
in
the
bone
was
also
significantly
lower.
Moreover,
the
analytical
results
revealed
that
the
bones
from
cultured
eels
having
abnormal
vertebrae
fractional
group
had
a
re-
latively
low
level
of
Zn.
Introduction
The
study
of
nutritional
requirement
of
trace
elements
in
fish
has,
with
few
exceptions,
been
performed
in
the
past
on
subjected
to
annex
with
formulated
white
fish
meal
diet.
In
previous
studies,'
,23
it
was
noticed
that
the
optimum
sup-
plementary
quantity
of
Al,
Fe,
Mn,
and
Cu
of
formulated
fish
meal
diet
for
eel.
The
present
study
was
also
under
taken
to
investigate
the
quantitative
requirement
of
zinc
in
the
basal
trace
element
mixture
and
the
effect
of
Zn
on
growth
and
mineral
compositions
in
different
tis-
sues
of
eel.
Zinc
occurs
widely
in
relatively
high
concentra-
tions
throughout
the
body.
It
is
a
predominant
mineral
in
animal
body
and
is
continuously
turned
over
in
various
tissues
and
plays
a
governing
role
in
certain
important
physiological
processes.
The
deficiency
in
trace
metals,
especially
a
shortage
of
Zn,
exerts
ill
effects
on
growth
and
eye.
33
Dietary
Zn
requirements
have
been
quantitated
for
the
rainbow
trout
Salmo
gairdneri
4)
and
the
carp
Cyprinus
earpio.
53
Therefore,
in
order
to
ob-
tain
better
growth
of
fish,
it
is
important
to
study
the
role
of
dietary
Zn
and
determine
favorable
supplemental
level
of
this
element
to
their
growth.
Materials
and
Methods
Basal
compositions
of
the
experimental
diets
are
presented
in
Table
1.
The
test
diets
were
sup-
plemented
with
four
different
levels
of
Zn
i.e.,
0,
50,
100,
and
200
µgig
in
the
form
of
zinc
sulfate
anhydrous
(ZnSO
4
).
The
composition
of
the
mineral
mixture
used
in
this
experiment
is
shown
in
Table
2.
Mineral
mixture
consisted
of
basal
mineral
mixture
and
basal
trace
element
mixture
excluding
Zn.
The
feeding
experiments
were
carried
out
for
120
days
and
the
fishes
were
weighted
on
30th,
60th,
90th,
and
120th
day.
At
the
end
of
feeding
experiment,
growth
factor
and
feed
efficiency
were
calculated.
More
than
IS-
20
fishes
in
large
group
were
sampled
from
each
experimental
tank,
and
dissected
to
separate
the
liver,
muscle,
and
bone.
The
liver
and
muscle
of
each
fish
were
weighed
and
stocked
in
a
freezer
at
-20°C
until
analysis.
Other
experimental
conditions,
such
as
pre-
paration
of
diets,
fish
care,
feeding
method,
and
analytical
method,
etc.
were
identical
to
those
described
earlier.°
On
the
other
hand,
The
mineral
contents
of
the
bone
of
eels
with
normal
and
abnormal
vertebrae
were
investigated
from
the
fish
farm
of
eel
in
*1
Studies
on
Quantity
of
Trace
Elements
in
the
Formulated
Diets
for
the
Young
Eel
Anguilla
japonica-III.
*2
Part
of
this
study
was
presented
at
the
Annual
Autumn
Meeting
of
the
Japanese
Society
of
Scientific
Fisheries
on
October
of
1987.
*3
Fisheries
Reserach
Laboratory,
Faculty
of
Agriculture,
University
of
Tokyo,
Maisaka,
Hamana,
Shizuoka
431-02,
Japan
(t1-
M*T1
1
::
A
-
A
-
-3A*1113*MreT).
*4
Present
Adress:
Korea
Ocean
Research
&
Development
Institute,
P.
0.
Box
29
Panwol
Ind.,
425-600,
Korea.
2138
Park
and
Shimizu
Table
1.
Composition
of
the
experimental
diet
Ingredient
cx.
White
fish
meal
71
a-Starch
20
Carboxymethyl
cellulose
3
Vitamin
mixture
1
Major
mineral
mixture*
4.75
Basal
trace
element
mixture*
0.25
*
Composition
of
the
mineral
and
trace
element
mixture
are
show
in
Table
2.
Table
2.
Copmosition
of
the
mineral
mixture
Major
mineral
mixture
Chemical
Composition
(%)
Ca(CH
3
CHOHC00)
2
K2SG4
Na
2
HPO
4
KH2PO4
(MgCO
3
)
4
Mg(011)
2
MgSO
4
Basal
trace
element
mixture
To
make
100
Basal
trace
element
mixture
Chemical
Content
(g)
Ferric
ammonium
citrate•Brown
60.0
CuSO
4
•5H
2
0
0.3
MnSO
4
•5-6
H
2
O
1.2
KIO,
0.6
NaF
0.6
CoC1,
2.0
ZnSO
4
0
A1C1
3
0.3
Hamana,
Shizuoka
Prefecture,
Japan
at
1985.
Results
and
Discussion
The
results
of
the
feeding
experiment
are
sum-
merized
in
Table
3.
Fish
on
diet
supplemented
with
50
200
,ug/g
level
of
Zn
(diet
no.
2-
3)
were
observed
to
have
the
high
values
of
average
body
weight,
growth
factor,
and
feed
efficiency.
Among
these
group,
diet
no.
2-
,
3
showed
the
high
growth.
The
mortality
of
the
group
was
6.7%,
the
value
being
the
lowest
among
those
experimental
groups.
The
diet
without
supplementary
Zn
failed
to
pro-
mote
growth
rate.
It
has
been
noticed
earlier
that
the
Zn
deficiency
induced
retarded
growth
and
high
mortality
in
rainbow
trout
and
carp."
,
"
As
shown
in
Table
4,
the
white
fish
meal
used
in
this
experiment
had
a
considerably
low
Zn
level
of
24.5
µg/g,
as
compared
with
the
other
white
fish
meals
which
usually
have
a
Zn
concentration
in
the
range
of
50-
100
µg/g.
This
indicates
that
the
Zn
contained
in
the
white
fish
meal
may
not
satisfy
the
requirement
of
young
eel.
The
white
fish
meal
based
diet
without
supplementary
Zn
ap-
parently
satisfies
Zn
requirement
of
rainbow
trout
by
Zn
derived
from
white
fish
meal,
but
induced
deficiency
symptoms
such
as
poor
growth,
dwarf-
ism,
and
cataract,
as
reported
by
Ketola"
and
Satoh
et
al.,'
-8
'
This
is
because
the
tricalcium
phosphate
in
diet
is
one
of
the
inhibitors
against
Zn
bioavaliability."
)
These
facts
indicates
that
50-S
100
pg/g
is
the
optimum
level
of
supplemental
concentration
of
Zn
in
the
formulated
white
fish
meal
diet
better
growth
and
health
of
young
eel.
The
hepatosomatic
index
and
condition
factor
of
eels
measured
at
the
end
of
feeding
experiment
34.2
25.0
21.1
8.7
3.0
3.0
5.0
Table
3.
Results
of
a
120-day
feeding
trial
Content
Diet
no.
1
(0
//gig)
2
3
(50
µg/g)
(100
µg/g)
4
(200
peg)
No.
of
fish
at
start
450 450
450
450
Initial
average
body
weight
(g)
Average
body
weight
after
30th
day
(g)
Average
body
weight
after
60th
day
(g)
Average
body
weight
after
90th
day
(g)
Average
body
weight
after
120th
day
(g)
0.38
0.78
1.28
2.57
5.38
0.39
0.82
1.9G
3.86
7.60
0.38
0.74
1.84
3.70
7.83
0.39
0.70
1.55
3.09
7.01
Growth
factor
13.2
18.5
19.6
17.0
Feed
efficiency
(%)
43.3
65.1
58.6
54.7
Mortality
(%)
10.9
12.2
6.7
22.9
Suitable
level
of
Zn
for
the
Young
Eel
2139
are
shown
in
Table
5.
The
former
indicates
that
there
are
no
significant
difference
in
the
value
among
the
experimental
groups.
It
appears
that
the
groups
with
a
high
growth
rate
are
accom-
pained
by
high
values
of
hepatosomatic
index.
On
the
other
hand,
the
short-body
dwarfism
is
the
result
of
arrested
longitudinal
growth
of
the
vertebrae
and
the
most
appearent
external
sign
of
growth."
)
In
this
experiment
eels
fed
with
a
Table
4.
Mineral
composition
of
white
fish
meal
White
fish
meal
Ca
(mg/g)
51.70
Mg
(mg/g)
2.23
Na
(mg/g)
7.40
K
(mg/g)
1.62
P
(mg/g)
33.70
Fe
(nig)
217.00
Cu
(nig)
1.63
Mn
(pg/g)
6.06
Zn
(ug/g)
24.50
Co
(µg/g)
19.00
Al
(leg)
25.20
diet
without
Zn
exhibited
a
high
value
of
con-
dition
factor
(19.0)
and
short-body
dwarfism,
suggesting
that
the
short-body
dwarfism
are
closely
related
to
a
deficiency
of
Zn
in
the
mineral
mixture.
These
results
are
in
agreement
with
the
report
of
Watanabe
et
a1.,
31
who
found
that
the
deficiency
of
Zn
and
Mn
in
fish
meal
diet
results
in
the
short-body
dwarfism,
as
well
as
the
malfor-
mation
of
head
and
cause
cartaracts
in
rainbow
trout
and
chum
salmon.
Fig.
1
shows
the
mineral
composition
of
the
bone
Table
5.
Hepatosomatic
index
and
condition
factor
of
eels
in
various
levels
of
dietary
Zn
feeding
ex-
periment
Hepatosomatic*i
Condition*
2
index
(%)
factor
1(
0
peg)
2.97±0.62*
3
2
(
50
µg/g)
2.77+0.76
3
(100
µg/g)
2.88+0.50
4
(200
µg/g)
2.76+0.84
*
1
Liver
weight
(g)
x
100/body
weight
(g).
.
2
Body
weight
(g)
x
100/body
lengths
(cm).
*
8
Mean±S.D.
(n=15).
Diet
no.
19.0+3.1
13.5+1.5
14.0+1.5
13.2+1.6
200
c
g'
••••••
150
-
50
4
O
tri
0•.
'
100-
A
O
0
c
G.
o
80
0
C43
o
0.
015
40
Fs
101
Co
Cu
0
50
100
200
Supplementary
concentration
(Ag/g)
Fig.
1.
Effect
of
supplementary
Zn
concentration
in
diet
on
different
trace
metals
lvels
in
the
bone
of
eel.
2140
Park
and
Shimizu
Table
6.
Comparison
of
mineral
content
of
bone
with
normal
and
abnormal
vertebrae
cultured
in
fish
farm
eel
(dry
&
fat-free
basis)
Mineral
content
Abnormal
vertebrae
Normal
vertebrae
Ca
(mg/g)
85.20
87.10
83.20
77.60
94.10
85.90
80.70
85.80
Mg
(mg/g)
2.81
2.39
2.55
2.62
2.57
2.60
2.57
2.89
Na
(mg/g)
3.42
3.50
3.58
3.47
3.80
3.61
3.56
3.62
K
(mg/g)
1.50
1.34
1.50
1.49
1.48
1.53
1.67
1.70
P
(mg/g)
61.00
60.60
57.70
59.20
50.90
63.70
60.10
71.50
Fe
(ag/g)
55.60
59.60
48.60
37.50
45.50
46.60
63.10
55.50
Cu
(nig)
3.06
2.90
2.75
2.64
2.84
3.01
2.73
2.94
Mn
(pg/g)
19.40
18.10
17.00
17.80
16.70
14.30
15.60
15.60
Zn
(pg/g)
63.30
37.50
25.30
44.50
50.90
98.50
121.00
125.00
Co
(peg)
14.70
14.80
13.50
13.40
15.40 13.90
12.80
13.70
Al
(nig)
60.50
51.80
60.10
36.40
23.60
28.70
31.60
25.60
Body
weight
(g)
219
192
256
198
136
204 224
195
Body
length
(cm)
50.8
47.8
53.4
48.4
44.2
50.8
52.7
49.0
120.
80.
CC
a
0
M
-0
C
0
.0
to
0 0
0-,
3
1
0
C
0
0
3
-
O
C.)
Fe
Zn
'
C
o
f
trace
me
ta
l
20.
Co
50
100
200
Supplementary
concentration
(
A
g/g)
Fig.
2.
Effect
of
supplementary
Zn
concentration
in
diet
on
different
trace
metals
levels
in
the
liver
of
eel.
of
eel
at
the
end
of
the
feeding
experiment.
The
content
of
Zn
in
bone
was
significantly
lower
in
the
fish
fed
on
the
diet
without
supplementation
of
Zn
(diet
no.
1).
Moreover,
Table
6
shows
the
mineral
contents
of
the
bone
of
eels
with
normal
and
abnormal
vertebrae
from
the
eel
farm.
Based
upon
these
results
it
can
be
said
that
eels
with
abnormal
Suitable
level
of
Zn
for
the
Young
Eel
2141
vertebrae
generally
have
a
relatively
low
level
of
Zn
in
the
bone.
These
results
strongly
suggest
that
the
abnormality
in
bone
is
closely
related
to
a
concentration
of
Zn
in
the
bone.
Marked
increases
in
Zn
and
Fe
contents
of
the
bone
were
indicated
among
the
groups
treated
with
high
levels
of
dietary
Zn.
The
mineral
contents
of
the
liver
are
showed
in
Fig.
2.
The
hepatic
Zn
concentrations
were
quite
different
between
the
group
fed
diet
without
supplementation
of
Zn
(diet
no.
1)
and
those
fed
diets
with
Zn
supplementation
(diet
no.
2
4).
The
hepatic
Zn
level
rose
from
7.9
pg/g
wet
weight
basis
in
the
fish
fed
a
diet
without
a
supplementa-
tion
of
Zn
to
a
high
plateau
(13.6-
16.1
µg/g)
in
the
fish
fed
diet
with
Zn
annexing
diet.
Thus
it
can
be
said
that
the
hepatic
Zn
level
of
14-
16
leg/
g
is
a
homeostatic,
controled
level
in
eel.
The
present
data
indicates
a
marked
decrease
in
hapatic
Fe
and
Co
contents
in
high
Zn
supplementary
groups.
The
above
discrepancy
between
the
rapid
approching
characteristics
to
the
narrow
level
of
zinc
hemostasis
in
the
liver
Zn
level
and
accumulation
of
Zn
in
the
bone
appears
to
be
very
important
in
delineating
the
role
of
Zn
metabolism
in
the
young
eel.
Acknowledgements
We
wish
to
express
our
thanks
to
a
large
number
of
colleagues
at
Fisheries
Research
Laboratory,
University
of
Tokyo,
Shizuoka
Prefecture,
Who
have
been
generous
and
helpful.
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C.-W.
Park
and
C.
Shimizu:
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Suisan
Gakkaishi,
55,
111-116
(1989).
2)
C.-W.
Park,
and
C.
Shimizu:
Journal
of
Aquacu-
lture,
1,
113-118
(1988).
3)
T.
Watanabe,
T.
Takeuchi,
and
C.
Ogino:
Nip-
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Suisan
Gakkaishi,
46,
1521-1525
(1980).
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C.
Ogino
and
G.
Y.
Yang:
Nippon
Suisan
Gak-
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44,
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C.
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Y.
Yang:
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Suisan
Gakkaishi,
45,
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(1979).
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H.
G.
Ketola:
.1.
Nutr.,
109,
965-969
(1979).
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Satoh,
H.
Yamamoto,
T.
Takeuchi,
and
T.
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Suisan
Gakkashi,
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425-
429
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Y.
Narabe,
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Wata-
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Suisan
Gakkaishi,
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(1983).
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S.
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Takeuchi,
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Suisan
Gakkaishi,
53,
595-599
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S.
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Takeuchi,
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Suisan
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Doctor
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37-30.
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