94
Aquaculture of Cypnids
'
»
551
rates
of absorption, metabolism and growth were similar to the trends of
food consumption. Food absorption efficiency did not change significantly
(around 83%) and the conversion efficiency showed a gradual and significant
@!
reduction with the increasing concentration of pesticides. An analysis of
protein, carbohydrate and lipid contents showed a sharp decrease in the
muscle, liver and intestine of fish reared in pesticides.
INFLUENCE OF FEED, PROTEIN OR ENERGY RESTRICTION WITH FOLLOWING REALIMENTA—
TION ON GROWTH, FOOD CONVERSION AND CARCASS COMPOSITION OF CARP (Cyprinus
Carpio L.) . J. SCHL‘JARZ and M. KÏRCHGEBNER, IML£ÆuÆ fi/1
defi Tech…chen UMV…ÆÆàÇÉ Münche, 8050,
GERMANY.
‘
Fish are often exposed to a varying supply of energy or crude protein besidæ
a
restriction of the feed quantity in the natural environment so that resüctive phases alternate with periods of satisfactory supply. ln two experimen—
tal
series
(ES) the influence of a graded reduction of the feed supply (ES D
or
of a
limited crude protein or energy supply (ES Il) with following
adequate supply (realimentation) as compared to continuously fed carp on œ
performance parameters of carp (Cyprinus carpio L.) is investigated. The
experiments were carried out in tanks (13 and 10 carps per tank, respectively)
with three or four replications per treatment. The mean water temperature was
Î
24°C.
ES
1
:
during the restriction phase, which was set at the weight range
of
163 — 284 g,
the
feed level was
2.0Z
(control, group 1), 1,52 (group 2),'
1.0Z
(group 3 of the live weight. The limitation of the feed supply to 0.7%
(group 4) and 0% (group 5) of the live weight was conducted by means of a
temporarily limited restriction period of 21 days. During the following
1
realimentation period, which was stopped at a mean weight of 520 g, all trial
groups were
given a feed supply of 2.0Z of the live weight. As a result of
the
feed restriction, daily gains and food conversion drop significantly.
The
carcass
composition shows a significant change only at a reduction of ܜ
feed supply from 2.02 of the live weight to 1.02 and less. During the
realimentation period, growth results are generally lower for the carp which
had been fed restrictively than for the control group. The carcass
tion of
the
five treatment groups is about the same after the end of the
realimentation period. ES Il : ES II was set up over a range in live weight
of
150 — 440 g with a restriction period from 150 — 250 g and a realimenta—
tion period from 250 — 440 g. The control group (treatment C) was given a
feed with
18.7 kJ gross energy/g fresh matter (FM) and 38.82 crude protein
in the FM at a level of 2% of the live weight. During the restriction phase
either the crude protein supply was reduced by about 30% with constant
energy supply (treatment P), or the gross energy supply was reduced by about
37% with constant crude protein supply (treatment E). In the following
realimentation phase all carp were fed as the control group. The restrictive
protein or energy supplies clearly slow the growth, but only in treatment
P
an
increased feed expenditure per g gain can be observed. In the realimentation phase treatments P and E reach a weight development similar to the
control
carp.
As
compared to the control group, the protein restriction leads
to
carcasses
richer in dry matter, fat and energy. After the energy restriction,
the carcasses
are
poorer
in dry matter, fat and energy, but richer in
protein than the control carp. In the course of the realimentation, the
differences especially between treatments P and C diminish, but the carcasses
of
treatment
P are
still fattest. The carcasses of treatment E contain least
fat, even after realimentation. The generally low feed expenditure per g
gain of
this trial group must be considered in this connection. But in
general of both ES it can be concluded that no compensatory growth effect
occurs.
Aquaculture of Cypnids
'
»
551
rates
of absorption, metabolism and growth were similar to the trends of
food consumption. Food absorption efficiency did not change significantly
(around 83%) and the conversion efficiency showed a gradual and significant
@!
reduction with the increasing concentration of pesticides. An analysis of
protein, carbohydrate and lipid contents showed a sharp decrease in the
muscle, liver and intestine of fish reared in pesticides.
INFLUENCE OF FEED, PROTEIN OR ENERGY RESTRICTION WITH FOLLOWING REALIMENTA—
TION ON GROWTH, FOOD CONVERSION AND CARCASS COMPOSITION OF CARP (Cyprinus
Carpio L.) . J. SCHL‘JARZ and M. KÏRCHGEBNER, IML£ÆuÆ fi/1
defi Tech…chen UMV…ÆÆàÇÉ Münche, 8050,
GERMANY.
‘
Fish are often exposed to a varying supply of energy or crude protein besidæ
a
restriction of the feed quantity in the natural environment so that resüctive phases alternate with periods of satisfactory supply. ln two experimen—
tal
series
(ES) the influence of a graded reduction of the feed supply (ES D
or
of a
limited crude protein or energy supply (ES Il) with following
adequate supply (realimentation) as compared to continuously fed carp on œ
performance parameters of carp (Cyprinus carpio L.) is investigated. The
experiments were carried out in tanks (13 and 10 carps per tank, respectively)
with three or four replications per treatment. The mean water temperature was
Î
24°C.
ES
1
:
during the restriction phase, which was set at the weight range
of
163 — 284 g,
the
feed level was
2.0Z
(control, group 1), 1,52 (group 2),'
1.0Z
(group 3 of the live weight. The limitation of the feed supply to 0.7%
(group 4) and 0% (group 5) of the live weight was conducted by means of a
temporarily limited restriction period of 21 days. During the following
1
realimentation period, which was stopped at a mean weight of 520 g, all trial
groups were
given a feed supply of 2.0Z of the live weight. As a result of
the
feed restriction, daily gains and food conversion drop significantly.
The
carcass
composition shows a significant change only at a reduction of ܜ
feed supply from 2.02 of the live weight to 1.02 and less. During the
realimentation period, growth results are generally lower for the carp which
had been fed restrictively than for the control group. The carcass
tion of
the
five treatment groups is about the same after the end of the
realimentation period. ES Il : ES II was set up over a range in live weight
of
150 — 440 g with a restriction period from 150 — 250 g and a realimenta—
tion period from 250 — 440 g. The control group (treatment C) was given a
feed with
18.7 kJ gross energy/g fresh matter (FM) and 38.82 crude protein
in the FM at a level of 2% of the live weight. During the restriction phase
either the crude protein supply was reduced by about 30% with constant
energy supply (treatment P), or the gross energy supply was reduced by about
37% with constant crude protein supply (treatment E). In the following
realimentation phase all carp were fed as the control group. The restrictive
protein or energy supplies clearly slow the growth, but only in treatment
P
an
increased feed expenditure per g gain can be observed. In the realimentation phase treatments P and E reach a weight development similar to the
control
carp.
As
compared to the control group, the protein restriction leads
to
carcasses
richer in dry matter, fat and energy. After the energy restriction,
the carcasses
are
poorer
in dry matter, fat and energy, but richer in
protein than the control carp. In the course of the realimentation, the
differences especially between treatments P and C diminish, but the carcasses
of
treatment
P are
still fattest. The carcasses of treatment E contain least
fat, even after realimentation. The generally low feed expenditure per g
gain of
this trial group must be considered in this connection. But in
general of both ES it can be concluded that no compensatory growth effect
occurs.