58
K. Dabrowski et ai.
Il.
NUTRITIONAL REQUIREMÈNTS_
The optimum protein content in carp diet was estimated to be 352 (see
Jauncey,
1982) but in diet containing 18% lipid it was possible to reduce
protein level from 45 to 29% without the decrease in weight gain. There is
indication that the optimum protein level decreases considerably during grass
carp ontogenesis. In fish of 0.2, 2.4 and 8 g individual body weight, the
maximum growth was achieved at 42, 37.7 and 26.5Z of protein in the diet
(Dabrowski, 1977; Ding et al., 1980). This aspect certainly needs further
Ï
attention since in comparable way, any
fish species has been studied in
respect to ontogenetic changes in protein (nutrients) requirements.
_
The role of
lipid in increasing carp growth is connected with qualita—
tive aspect of protein utilization and plant protein could be ideal substi—
tute
for animal protein in carp diet when processed and supplemented with de—
ficient amino acids
(Viola et al., 1982, 1983). The soybean oil has been of
equal value in carp diet to animal oils.
Dietary carbohydrate source utilization in carp can be affected consi—
derably by frequency of feeding, but growth rate of fish fed maltose or glu—
cose
can
be as
good or better as in fish fed starch (Murai et al., 1983a).
Ingestion of oxidized lipids during 45 weeks in carp led to the 602 re—
duètion of growth and tocopherol was not able to reverse these changes
(Iijima and Zama, 1979). Further studies (Tijima et al. 1983) elucidated that
the oxidized lipid do not affect conversion of glycerol—3—phosphate to phos—
pholipid precursor, but they inhibit to 25% the synthesis of di— and trigly—
cerides via phosphatidic acid. ln carp induction of desaturases activity in
formation of polyunsaturated fatty acids (PUFA) by cold adaptation take place
only during 48—72 hours (Schünke and Wodtke, 1983). Both in vivo and in Vitro
preparations (Parkas, 1984) proved that the level of PUFÀ_ËharacterisËÎc—fËË_
winter carp is achieved within few hours in liver slices of both cold— and
warm—adapted fish. Ectothermal carp seems to lack endogenous control of fatty
acid synthesis at least in phospholipids.
A.
Amine acid requirements
Various test diets composed of crystaline amino acids were formulated to
determine the essential amino acids of common carp, but utilization of these
diets were extremely poor (Ace et al. 1970). Later it was found by Nose et
al.
(1974) that carp shows a certain growth response if pH of the amino acid
diet is adjusted to higher than 5. Using this diet it was determined that the
same
10 amino acids as those for most animals, are indispensable for carp
growth. Quantitative requirements of amino acids were established (Nose, 1979)
based on the growth response of fish fed the pH adjusted diet for 6 weeks
(Tabl. 1). As has been recognized in other fish, cystine and tyrosine can
spare or replace certain portions of dietary methionine and phenylalanine,
£
respectively. erai et al. (1983b) were able to improve utilization of amino
acid
mixture diet, and growth of carp by supplementation of K up to 1.41%, and
this line of research should be continued.
Ogino (1980) proposed that amino acid requirements can be estimated from
data on amino acid composition of the whole body and daily body protein depo—
sition.
If
a
diet containing 35% protein with 80% of protein absorbability is
fed at a level of 3% biomass daily, it can be assumed that fish deposites
0,58 g of protein per 100 g of body weight daily. Data based on this assump*
tion are
also shown in Tabl.
1.
Requirements determined by these two methods
agreefa1r1y'well. however, theVdeposition rate does not account for metaboàÈÊQÊÊ£ÏÏÎÏÊy°ÊfaÎÊÊÎVÎÊÈdÎ which
do not lead to protein synthesis. Also,
a
amino
ac1ds
greatly differ depend on protein
{
source
and time after feeding (Dabrowski, 1983a, 1986). In this context, the
K. Dabrowski et ai.
Il.
NUTRITIONAL REQUIREMÈNTS_
The optimum protein content in carp diet was estimated to be 352 (see
Jauncey,
1982) but in diet containing 18% lipid it was possible to reduce
protein level from 45 to 29% without the decrease in weight gain. There is
indication that the optimum protein level decreases considerably during grass
carp ontogenesis. In fish of 0.2, 2.4 and 8 g individual body weight, the
maximum growth was achieved at 42, 37.7 and 26.5Z of protein in the diet
(Dabrowski, 1977; Ding et al., 1980). This aspect certainly needs further
Ï
attention since in comparable way, any
fish species has been studied in
respect to ontogenetic changes in protein (nutrients) requirements.
_
The role of
lipid in increasing carp growth is connected with qualita—
tive aspect of protein utilization and plant protein could be ideal substi—
tute
for animal protein in carp diet when processed and supplemented with de—
ficient amino acids
(Viola et al., 1982, 1983). The soybean oil has been of
equal value in carp diet to animal oils.
Dietary carbohydrate source utilization in carp can be affected consi—
derably by frequency of feeding, but growth rate of fish fed maltose or glu—
cose
can
be as
good or better as in fish fed starch (Murai et al., 1983a).
Ingestion of oxidized lipids during 45 weeks in carp led to the 602 re—
duètion of growth and tocopherol was not able to reverse these changes
(Iijima and Zama, 1979). Further studies (Tijima et al. 1983) elucidated that
the oxidized lipid do not affect conversion of glycerol—3—phosphate to phos—
pholipid precursor, but they inhibit to 25% the synthesis of di— and trigly—
cerides via phosphatidic acid. ln carp induction of desaturases activity in
formation of polyunsaturated fatty acids (PUFA) by cold adaptation take place
only during 48—72 hours (Schünke and Wodtke, 1983). Both in vivo and in Vitro
preparations (Parkas, 1984) proved that the level of PUFÀ_ËharacterisËÎc—fËË_
winter carp is achieved within few hours in liver slices of both cold— and
warm—adapted fish. Ectothermal carp seems to lack endogenous control of fatty
acid synthesis at least in phospholipids.
A.
Amine acid requirements
Various test diets composed of crystaline amino acids were formulated to
determine the essential amino acids of common carp, but utilization of these
diets were extremely poor (Ace et al. 1970). Later it was found by Nose et
al.
(1974) that carp shows a certain growth response if pH of the amino acid
diet is adjusted to higher than 5. Using this diet it was determined that the
same
10 amino acids as those for most animals, are indispensable for carp
growth. Quantitative requirements of amino acids were established (Nose, 1979)
based on the growth response of fish fed the pH adjusted diet for 6 weeks
(Tabl. 1). As has been recognized in other fish, cystine and tyrosine can
spare or replace certain portions of dietary methionine and phenylalanine,
£
respectively. erai et al. (1983b) were able to improve utilization of amino
acid
mixture diet, and growth of carp by supplementation of K up to 1.41%, and
this line of research should be continued.
Ogino (1980) proposed that amino acid requirements can be estimated from
data on amino acid composition of the whole body and daily body protein depo—
sition.
If
a
diet containing 35% protein with 80% of protein absorbability is
fed at a level of 3% biomass daily, it can be assumed that fish deposites
0,58 g of protein per 100 g of body weight daily. Data based on this assump*
tion are
also shown in Tabl.
1.
Requirements determined by these two methods
agreefa1r1y'well. however, theVdeposition rate does not account for metaboàÈÊQÊÊ£ÏÏÎÏÊy°ÊfaÎÊÊÎVÎÊÈdÎ which
do not lead to protein synthesis. Also,
a
amino
ac1ds
greatly differ depend on protein
{
source
and time after feeding (Dabrowski, 1983a, 1986). In this context, the