Feed consumption growth and protein util (1)
Aquaculture Research, 1996, 27, 531-538
Feed consumption, growth and protein utiiization of
Colossoma macropomum (Cuvier) at different dietary
fish meal/soya meal ratios
M B van der Meer,'-^ E A Huisman^ & M C J Verdegem^
'Programa UNA-LUW, Escuela de Ciencias Biologicas. Universidad Nacional, Heredia, Costa Rica, and ^Department of Fish
Culture and Fisheries, Wageningen Agricultural University, Wageningen, The Netherlands
Correspondence: M B van der Meer, Department of Fish Culture and Fisheries. Wageningen Agricultural University, P 0
Box 3 3 8, 6 700 AH Wageningen, The Netherlands
Abstract
The effect of a gradual substitution of dietary fish
meal protein by soya meal protein on growth, feed
uptake and protein utilization of 1 g Colossoma macropomum (Cuvier) was studied at two different dietary
protein levels. Growth rates of fish fed ad libitum 20
and 45% protein diets fluctuated between 41 and
49, and between 60 and 68 gkg-"" day-', respectively.
Fish incorporated between 31 and 47% of the dietary
protein in their body. Increased amounts of soya meal
in the diet led to decreased feed uptake, higher body
protein levels, lower ash levels and increased NPU
values. If the low ash contents in the fish fed 100%
soya diets are not prejudicial for health and growth of
the fish in the long term, soya meal must be considered
a superior protein source for C. macropomum. The high
growth and the efficient use of the dietary protein
indicate the C. macropomum is able to utilize soya
protein more efficiently than other fish species.
Introduction
Under laboratory conditions, juvenile Colossoma
macropomum (Cuvier) can attain growth rates up to
52-55 g kg-"" day-' (Gtinther & Boza 1993; Van der
Meer, Machiels&Verdegeml995),These high growth
rates require the use of dietary protein levels above 40%
(Van der Meer et al. 1995), Because protein is the most
expensive macro-nutrient in artificial fish diets (Pillay
1990), and because feeds constitute usually the major
part of the production costs for intensive culture, the
use of cheaper dietary protein sources could play a key
role in optimizing the econotnics of C, macropomum
culttire.
Normally, fish meal is the main protein source in
© 1996 BlackweU Science Ltd.
experimental diets for C, macropomum. Fish meal
combines the properties of good taste and high protein quality, but it is also relatively expensive (Lovell
1989), Efforts to find cheaper dietary protein sources
usually start with the substitution of fish meal by soya
meal. Soya meal is generally considered the best
vegetable protein source, because it has a relatively
high protein content (betweeh 44 and 49%; Tacon
1987), an appropriate amino acid profile and high
protein digestibility (Lovell 1991).
In tilapia, channel catfish and rainbow trout, it
was found that protein from solvent-extracted soya
meal was equally or more digestible than fish meal
protein (Lovell 1991), However, to judge protein quality, one has not only to consider protein digestibility,
but also the amino acid composition. The chemical
score (CS) gives an indication of the resemblance
between the indispensable amino acid (IAA) profile
of dietary protein and that of body protein, and as
such, can be used to judge the amino acid composition of a diet (Hepher 1988), Based on CSs, and
asstiming equal digestibility of soya and fish meal. Van
der Meer & Verdegem (1995) calculated that 90%
of the fish meal of a 'standard diet' could be substituted by soya meal without affecting the growth of
C. macropomum.
Substitution of fish meal by soya meal as the main
protein source has been investigated in carp (Viola,
Mokady, Rappaport & Arieli 1982), channel catfish
(Mohsen & Lovell 1990), African catfish (Machiels
1987), rainbow trout (Dabrowski, Poczyczynski, Kock
&Berger 19 89) and shrimp (Lim&Dominy 1990).The
general conclusion from the experiments mentioned
above is that the effect of a partial substitution of fish
meal by soya meal depends on the species studied;
however, complete substitution restated in significantly
531
Fish meal/soya meal ratios in Colossoma diets M B van der Meer et al.
Aquaculture Research, 1996, 27, 531-538
filter. Water losses caused hy evaporation and cleaning
reduced growth rates in all cases. Once the IAA
were compensated daily.
compositions of fish and dietary ingredients are
. Ten different diets were made of locally available
known, the CS of a diet can be calculated without
ingredients (Table 1), which were ground until these
additional experimental data. However, for the definicould pass easily through a 1-mm mesh sieve. Ingretive determination of the suitability of a dietary protein,
dients for each diet were mixed for 20 min hefore
biological testing taking feed uptake and growth into
adding water to obtain a paste. The latter was pressed
account is recommended (Steward Anderson, Lall,
into spaghetti-like strings, which were dried at 75°C
Anderson & McNiven 1993).
for 15 h. Depending on fish size, the dried feed was
The generally poor performance of plant protein
crumbled into particles small enough for the fish to
in comparison to fish meal protein is not necessarily
eat. Feeds were stored at 5°C. Storage time was always
the result of an inferior protein quality, hut could also
less than 6 weeks.
be caused by the presence of anti-nutritional factors,
Two feeding experiments were executed. In expertoxic substances, high fibre content or lower paliment 1, five 45% protein diets (diets 1-5), and in
atibility (Lim & Dominy 1991). In this context, adult
C. macropomum is special in that it feeds mainly on experiment 2,five20% protein diets (diets 6-10) were
tested (Table 1). Fish meal protein was gradually
fruits and seeds in nature (Saint-Paul 1985). Such a
substituted by soya meal protein in diets 1-5 and in
preference has not been reported for any of the other
diets 6-10. Diets within one protein level are further
fish species mentioned. Therefore, we supposed that
C. macropomum would he less susceptible to the referred to as 0, 15, 43, 77 and 100% soya diets,
depending on the proportion of soya in the diet calconstraints linked to the use of plant protein.
culated
as; % soya meal protein/(% soya meal
In the present study, we determined the effects of
protein
+
% fish meal protein)* 100. Within each
substitution offishmeal hy soya meal on feed uptake,
experiment,
diets were formulated to he isocaloric and
growth and protein utilization to test the assumption
isoproteic.
that C. macropomum is able to use soya and fish meal
Each experiment lasted 3 7 days. Fish were weighed
protein equally well. Diets in which soya meal suhon days 0, 14, 28 and 37, and fed ad libitum daily
stituted between 0 and 100% of the fish meal (more
at 0830, 1200 and 1630 h. Fish were not fed on
than 90%fishmeal, the rest being tankage and blood
sampling days. Each diet was tested six times. Feed
meal, further referred to asfishmeal), hut with similar
consumption for each aquarium was monitored daily
CSs, were tested at two dietary protein levels. Diets
Water temperature was measured at 8 and 17 h,
with the highest protein level (45%) were expected to
and maintained between 26,7 and 31.8°C, Water
allow maximal growth. Former experiments indicated
temperature averaged 28,3 and 2 8,8°C in experiments
that protein levels below 30% restricted growth of
C. macropomum (Van der Meer et al. 1995). Therefore, 1 and 2, respectively. Dissolved oxygen levels were
maintained above 4.3 ppm and nitrite levels below
more pronounced differences between treatments
0.05 ppm.
were expected with low protein diets (20%) than with
high protein diets (45%).
Standard proximate analysis was used to determine the composition of feeds and fish. At the start
of each experiment, a sample of about 75 fish was
taken for the determination of initial hody composition.
Materials and methods
At the end of the experiment, two samples per treatColossoma macropomum fry were obtained through ment, each comprisingfishfromthree aquaria, were
taken to determine final hody composition. Carbohormone-induced reproduction and subsequent arhydrates and fibre are quantitatively not important
tificial incubation. Larvae started to feed on Artemia
in C. macropomum (Gunther & Boza 1993; Van der
5-6 days after hatching and were weaned to dry feed
Meer
et al. 1995), and therefore, were ignored in the
when 80-100 mg in weight. Ten days before the
analysis.
experiments started, at a weight of about 0.5 g, the
Amino acid profiles of C. macropomum and ingrefish were transferred to the experimental units. At the
dients were taken from Van der Meer & Verdegem
start of the experiments,fishweighed 1.1 g (Table 2).
(1996). Dietary protein quality was evaluated with
The experiments were performed in 30 45-1 aquaria.
the CS (Hepher 1988), The minimal differences in
Aquaria belonged to a recirculation unit equipped
CSs between diets within each experiment (Tahle 1)
with a heating device, a sedimentator and a biological
532
©1996BlackweIlScienceLtd,A«UfleuitureResearch, 27, 531-538
Aquaculture Research, 1996, 2 7 , 531-538
Fish meal/soya meal ratios in Colossoma diets M B van der Meer et al.
Table 1 Diet composition expressed in per cent of dry matter
Experiment 1
Experiment 2
Diet
1
2
3
4
Ingredients
Fish meal
Tankage
Blood meal
Corn meal
Soya flour
Wheat flour
Soya oil
Fish oil
Salt
Premix
49.7
3.4
1.0
44.3
0.0
0.0
0.0
0.0
1,0
0.5
42.2
2.9
0.8
37.6
13.4
0.7
0.4
0.4
1.0
0.5
28.1
1.9
0.6
25.1
38.5
2.1
1.1
1.1
1.0
0.5
11.3
0.8
0.2
10.0
68.6
3.8
1.9
1.9
1.0
0.5
Proximate analysis
Protein
Lipids
Carbohydrates
Fibre
Ash
Energy (kj g-')'
45.9
7.1
28,8
2.8
15.4
18.5
44.3
7.3
29.9
4.0
14.6
18.4
43.5
5.6
32.2
6.9
11.8
17.9
% soya'
Chemical score
Limiting lAA^
0
76.0
lys
15
76.3
lys
43
77.1
lys
5
6
7
8
9
10
0.0
0.0
0.0
0.0
88.7
4.7
2.5
2.5
1.0
0.5
16.6
1.2
0.3
65.2
0.0
8.4
3.4
3.4
1.0
0.5
14.1
1.0
0.3
63.0
4.4
8.6
3.5
3.5
1.0
0.5
9.4
0.7
0.2
58.8
12.9
9.1
3.8
3.8
1.0
0.5
3.8
0.3
0.1
53.8
22.9
9.6
4.0
4.0
1.0
0.5
0.0
0.0
0.0
50.4
29.6
10.0
4.2
4.2
1.0
0.5
43.8
6.0
32.9
7.8
9.6
18.3
42.8
4.7
35.1
9.2
8.6
17.3
22.0
9.1
58.1
3.2
7.7
18.8
21.5
8.9
60.3
2.6
6.7
18.9
22.4
12.6
55.7
3.0
6.3
19.8
22.4
14.1
54.5
3.8
5.4
20.2
19.8
12.8
60.0
2.7
4.7
20.0
77
78.0
lys
100
78.6
lys
0
61.5
lys
15
61.7
lys
43
62.2
lys
77
62.7
lys
100
63.1
lys
' Ingredients: fish meal = brown tuna meal (66.2% protein, 8.8% fat, 0.2% carbohydrates, 4.2% crude fibre, 20.5% ash):
tankage = bone and meat meal: blood meal = mechanically dried; corn meal = pre-cooked white meal: soya flour = solvent
(hexane) extracted (43,7% protein, 5,1% fat, 38.2% carbohydrate, 8.1% crude fibre, 6.8% ash): premix = 'Vitamelk peces A',
Roche S.A., containing per kg: 3,48*10" IU vit A, 0.70*10' IU vit D3, 11 000IU vit E, 2.17 g vit K3, 4.35 g vit Bl, 8.70 g
vit B2, 43.5 g vit B3, 17.4 g pantothenic acid, 4.35 g vit B6, 74 mg vit B8, 1300 mg folic acid: 8.70 mg vit B12: 130 g
vit C, 130 g choline, 17.4 g magnesium, 17.4 g iron: 8.70 g zinc, 2.17 g copper, 435 g iodine, 43.5 mg selenium, 43,5 mg
cobalt.
* Energy content: gross energy content calculated using the following energy values: protein, 23.4 kJ g"'; lipid, 39,8 kJ g"':
and carbohydrates, 17.2 kJ g"' (Cho, Slinger & Bayley 1982),
* % soya, proportion of soya meal in the diet (see text).
* IAA, indispensable amino acid; lys, lysine.
allowed us to test the hypothesis that C. macropomum
uses soya and animal protein equally well.
The biological parameters used to evaluate dietary
protein quality were metabolic ration (MR, g kg"*'"
day^'), metabolic growth rate (MGR, g kg"" May"'),
feed conversion (FC, g dry feed g wet weight gain"') and
net protein utilization (NPU, g protein gain g feed
protein-'* 100).
Feed uptake, growth, feed utilization and body
composition parameters from each experiment were
submitted to a one-way ANOVA. The significance of
differences among diets within experiments were
determined by Tukey-test (Statistix 1990). Trends
©1996 BlackweU Science Ltd, Aquflcuiture Research, 27, 531-538
between the different treatments within each experiment were studied through quadratic regression
analysis: Y = J3,, + j3j*X, + ^/(K)^ + e, where: Y =
average value per treatment; P^, )3j and fi^ = regression
coefficients; X. = the soya proportion in diet i (i = 0,
15, 43, 77. 100). The quadratic component i3/(X,)was only included if it improved the adjusted r^ of the
regression (Statistix 1990).
Body protein content is affected byfishsize (Shearer
1994), which was also shown for C. macropomum
(Gunther & Boza 1993). To separate the effect of body
weight (Wf) from that of diet composition (% soya),
we performed a multiple linear regression analysis;
533
Fish meal/soya meal ratios in Colossoma diets M B van der Meer et al.
Aquaculture Research. 1996. 27, 531-538
protein gave a slight, but not significant, growth
increase in channel catfish.
The lack of significant differences in growth rates
at equal protein levels confirmed the hypotheses that
C. macropomum can grow equally well on soya and on
fish meal protein. In this respect, C. macropomum differs
from carp (Viola et al 1982), trout (Dabrowski et al.
1989), African catfish (Machiels 1987), channel catfish (Mohsen & Lovell 1990) and shrimp (lim & Dominy
1990). which all grew better on fish meal diets. In
African catfish (Machiels 1987) and channel catfish
(Andrews & Page 1974), addition of cristaline amino
acids could not prevent reduced growth with 100%
soya diets. This possibly also indicates that the amino
acid profile of soya was not the cause of its poorer
performance compared tofishmeal in those species.
Both feed conversion (Table 2; Fig. lc) and NPU
(Table 3; Fig. Id) tended to improve with increasing
soya levels in the diet. The feed conversions of 43, 77
and 100% soya diets were significantly lower than
those of the 0% soya diets. However, the NPU of the
100% soya meal diet was only significantly higher
than the 0% soya diet in experiment 2.
P ^ ^ = a + P*{% soya) + Y*(Wf) + e. where; P^^. =
average body protein percentage; a, j3 and y =
regression coefficients; e - error term.
Results and discussion
Feed consumption, growth and feed utilization
No significant differences were found between the MR
of fish fed 0. 15 or 43% soya diets (P > 0.05; Table 2;
Fig. la). However, the MR administrated with the
100% soya diets was significantly lower than the ration
given to the 15 or 4 3% soya diets. The reduced uptake
of diets with more than 43% soya could be caused by a
lower palatability of soya compared to fish meal.
Decreased palatability of diets containing soybean
meal was also reported in salmonids (Lovell 1991).
The growth rates obtained in experiment 1 with
the 45% protein diets (between 60.6 and 67.8 g
kg-08 day"'; Table 2) were comparable to maximum
growth rates reported previously (Giinther & Boza
1993; Van der Meer et al. 1995). The average growth
rate obtained in experiment 2 (44.3 gkg"""day"')
was comparable to growth rates formerly obtained in
our laboratory with similar low protein diets (Van der
Meer e£ai.l995).The43% soya diet tended to promote
better growth than 0 and 100% soya diets (Fig. lb).
However, no significant differences in growth rate
were found between treatments in both experiments.
Mohsen & Lovell (1990) also found that substitution
of about 50% of the fish meal protein by soya meal
Body composition
In both experiments, no significant differences were
found in body protein content between treatments
(Table 3; Fig. le). The regression (P^y = 9.51 +
0.0176*% soya + 0.119*Wf; r^ = 0.62, P < 0.001)
Table 2 Weight increase, feed consumption and feed conversion by experiment and diet*
Fish weight (g fish')
Experiment
Diet
Growth
Feed consumption
Feed
MR
(gkg-0
30
DO
40
SO
60
70
«}
90
too
I to
to
0
>0
20
30
40
10
20
M
40
so
so
so
00
70
so
90
100 n o
%soya
% soya
70
90
100 n o
0
to
10
70
30
40
% Soya
50
60
70
00
80
100 110
%soya
1• 0
0
10
20
X
40
so
flO
70
80
90
100
itO
%soya
Figure 1 Feed uptake, growth, feed utilization and body composition in relation to the soya protein proportion in the diet:
(a) feeding ration; (b) growth rate; (c) feed conversion; (d) net protein utilization; (e) body protein content; (1) body ash content.
X-axis: % soya, proportion of soya meal in the diet (see text); ( • ) experiment 1, 45% protein diets; (D) experiment 2, 20%
protein diets. Numbers near the markers indicate diet numher (seeTable 1); vertical solid lines indicate the standard deviation.
revealed that not only body weight (Wf;Pi-8S.
Statlstix (1990) An Interactive Analysis Program for Microcomputers. NH Analytical Software. St Paul. MN.
Steward Anderson ].. Lail S.P.. Anderson D.M. & McNivenM.A.
(1993) Evaluation of protein quality in fish meals by
chemical and biological assays. Aquaculture 115.305-325.
Tacon A.G.]. (19 8 7) The nutrition and feeding of farmed fish
and shrimp — a training manual. 2 — Nutrient sources
and composition. Field Document 5/E, GCP/RLA/075/ITA.
Food and Agriculture Organisation of the United Nations.
Brasilia.
Van der Meer M.B.. Machiels M.A.M. & Verdegem
M.C.J. (1995) Effect of dietary protein level on growth.
Aquaculture Research. 1996, 2 7 , 531-538
protein utilization and body composition of Colossoma
macropomum. Aquaculture and Fisheries Management 26.
901-909.
Van der Meer M.B. & Verdegem M.C.J. (1996) Comparison of
amino acid profiles of feeds and body protein as a quick
method for selecting promising feed ingredients: a case
study for C. macropomum (Cuvier). Aquaculture Research 27.
487-495.
Viola S.. Mokady S.. Rappaport U. & Arieli Y. (1982) Partial
and complete replacement of fish meal by soybean meal in
feeds for intensive culture of carp. Aquaculture 26. 2 2 3 236.
Viola S.. Zohar G. & Arieli Y. (1986) Phosphorous requirements and its availability from different sources for
intensive pond culture species in Israel. Part I: Tilapia.
Bamidgeh 3 8 . 3-12.
Watanabe T.. Satoh S. & Takeuchi T (1988) Availability of
minerals in fish meal to fish. Asian Fisheries Science 1.175195.
© 1996 Blackwell Science Ltd. AquflCuJtureReseardi. 27, 531-538
538
Feed consumption, growth and protein utiiization of
Colossoma macropomum (Cuvier) at different dietary
fish meal/soya meal ratios
M B van der Meer,'-^ E A Huisman^ & M C J Verdegem^
'Programa UNA-LUW, Escuela de Ciencias Biologicas. Universidad Nacional, Heredia, Costa Rica, and ^Department of Fish
Culture and Fisheries, Wageningen Agricultural University, Wageningen, The Netherlands
Correspondence: M B van der Meer, Department of Fish Culture and Fisheries. Wageningen Agricultural University, P 0
Box 3 3 8, 6 700 AH Wageningen, The Netherlands
Abstract
The effect of a gradual substitution of dietary fish
meal protein by soya meal protein on growth, feed
uptake and protein utilization of 1 g Colossoma macropomum (Cuvier) was studied at two different dietary
protein levels. Growth rates of fish fed ad libitum 20
and 45% protein diets fluctuated between 41 and
49, and between 60 and 68 gkg-"" day-', respectively.
Fish incorporated between 31 and 47% of the dietary
protein in their body. Increased amounts of soya meal
in the diet led to decreased feed uptake, higher body
protein levels, lower ash levels and increased NPU
values. If the low ash contents in the fish fed 100%
soya diets are not prejudicial for health and growth of
the fish in the long term, soya meal must be considered
a superior protein source for C. macropomum. The high
growth and the efficient use of the dietary protein
indicate the C. macropomum is able to utilize soya
protein more efficiently than other fish species.
Introduction
Under laboratory conditions, juvenile Colossoma
macropomum (Cuvier) can attain growth rates up to
52-55 g kg-"" day-' (Gtinther & Boza 1993; Van der
Meer, Machiels&Verdegeml995),These high growth
rates require the use of dietary protein levels above 40%
(Van der Meer et al. 1995), Because protein is the most
expensive macro-nutrient in artificial fish diets (Pillay
1990), and because feeds constitute usually the major
part of the production costs for intensive culture, the
use of cheaper dietary protein sources could play a key
role in optimizing the econotnics of C, macropomum
culttire.
Normally, fish meal is the main protein source in
© 1996 BlackweU Science Ltd.
experimental diets for C, macropomum. Fish meal
combines the properties of good taste and high protein quality, but it is also relatively expensive (Lovell
1989), Efforts to find cheaper dietary protein sources
usually start with the substitution of fish meal by soya
meal. Soya meal is generally considered the best
vegetable protein source, because it has a relatively
high protein content (betweeh 44 and 49%; Tacon
1987), an appropriate amino acid profile and high
protein digestibility (Lovell 1991).
In tilapia, channel catfish and rainbow trout, it
was found that protein from solvent-extracted soya
meal was equally or more digestible than fish meal
protein (Lovell 1991), However, to judge protein quality, one has not only to consider protein digestibility,
but also the amino acid composition. The chemical
score (CS) gives an indication of the resemblance
between the indispensable amino acid (IAA) profile
of dietary protein and that of body protein, and as
such, can be used to judge the amino acid composition of a diet (Hepher 1988), Based on CSs, and
asstiming equal digestibility of soya and fish meal. Van
der Meer & Verdegem (1995) calculated that 90%
of the fish meal of a 'standard diet' could be substituted by soya meal without affecting the growth of
C. macropomum.
Substitution of fish meal by soya meal as the main
protein source has been investigated in carp (Viola,
Mokady, Rappaport & Arieli 1982), channel catfish
(Mohsen & Lovell 1990), African catfish (Machiels
1987), rainbow trout (Dabrowski, Poczyczynski, Kock
&Berger 19 89) and shrimp (Lim&Dominy 1990).The
general conclusion from the experiments mentioned
above is that the effect of a partial substitution of fish
meal by soya meal depends on the species studied;
however, complete substitution restated in significantly
531
Fish meal/soya meal ratios in Colossoma diets M B van der Meer et al.
Aquaculture Research, 1996, 27, 531-538
filter. Water losses caused hy evaporation and cleaning
reduced growth rates in all cases. Once the IAA
were compensated daily.
compositions of fish and dietary ingredients are
. Ten different diets were made of locally available
known, the CS of a diet can be calculated without
ingredients (Table 1), which were ground until these
additional experimental data. However, for the definicould pass easily through a 1-mm mesh sieve. Ingretive determination of the suitability of a dietary protein,
dients for each diet were mixed for 20 min hefore
biological testing taking feed uptake and growth into
adding water to obtain a paste. The latter was pressed
account is recommended (Steward Anderson, Lall,
into spaghetti-like strings, which were dried at 75°C
Anderson & McNiven 1993).
for 15 h. Depending on fish size, the dried feed was
The generally poor performance of plant protein
crumbled into particles small enough for the fish to
in comparison to fish meal protein is not necessarily
eat. Feeds were stored at 5°C. Storage time was always
the result of an inferior protein quality, hut could also
less than 6 weeks.
be caused by the presence of anti-nutritional factors,
Two feeding experiments were executed. In expertoxic substances, high fibre content or lower paliment 1, five 45% protein diets (diets 1-5), and in
atibility (Lim & Dominy 1991). In this context, adult
C. macropomum is special in that it feeds mainly on experiment 2,five20% protein diets (diets 6-10) were
tested (Table 1). Fish meal protein was gradually
fruits and seeds in nature (Saint-Paul 1985). Such a
substituted by soya meal protein in diets 1-5 and in
preference has not been reported for any of the other
diets 6-10. Diets within one protein level are further
fish species mentioned. Therefore, we supposed that
C. macropomum would he less susceptible to the referred to as 0, 15, 43, 77 and 100% soya diets,
depending on the proportion of soya in the diet calconstraints linked to the use of plant protein.
culated
as; % soya meal protein/(% soya meal
In the present study, we determined the effects of
protein
+
% fish meal protein)* 100. Within each
substitution offishmeal hy soya meal on feed uptake,
experiment,
diets were formulated to he isocaloric and
growth and protein utilization to test the assumption
isoproteic.
that C. macropomum is able to use soya and fish meal
Each experiment lasted 3 7 days. Fish were weighed
protein equally well. Diets in which soya meal suhon days 0, 14, 28 and 37, and fed ad libitum daily
stituted between 0 and 100% of the fish meal (more
at 0830, 1200 and 1630 h. Fish were not fed on
than 90%fishmeal, the rest being tankage and blood
sampling days. Each diet was tested six times. Feed
meal, further referred to asfishmeal), hut with similar
consumption for each aquarium was monitored daily
CSs, were tested at two dietary protein levels. Diets
Water temperature was measured at 8 and 17 h,
with the highest protein level (45%) were expected to
and maintained between 26,7 and 31.8°C, Water
allow maximal growth. Former experiments indicated
temperature averaged 28,3 and 2 8,8°C in experiments
that protein levels below 30% restricted growth of
C. macropomum (Van der Meer et al. 1995). Therefore, 1 and 2, respectively. Dissolved oxygen levels were
maintained above 4.3 ppm and nitrite levels below
more pronounced differences between treatments
0.05 ppm.
were expected with low protein diets (20%) than with
high protein diets (45%).
Standard proximate analysis was used to determine the composition of feeds and fish. At the start
of each experiment, a sample of about 75 fish was
taken for the determination of initial hody composition.
Materials and methods
At the end of the experiment, two samples per treatColossoma macropomum fry were obtained through ment, each comprisingfishfromthree aquaria, were
taken to determine final hody composition. Carbohormone-induced reproduction and subsequent arhydrates and fibre are quantitatively not important
tificial incubation. Larvae started to feed on Artemia
in C. macropomum (Gunther & Boza 1993; Van der
5-6 days after hatching and were weaned to dry feed
Meer
et al. 1995), and therefore, were ignored in the
when 80-100 mg in weight. Ten days before the
analysis.
experiments started, at a weight of about 0.5 g, the
Amino acid profiles of C. macropomum and ingrefish were transferred to the experimental units. At the
dients were taken from Van der Meer & Verdegem
start of the experiments,fishweighed 1.1 g (Table 2).
(1996). Dietary protein quality was evaluated with
The experiments were performed in 30 45-1 aquaria.
the CS (Hepher 1988), The minimal differences in
Aquaria belonged to a recirculation unit equipped
CSs between diets within each experiment (Tahle 1)
with a heating device, a sedimentator and a biological
532
©1996BlackweIlScienceLtd,A«UfleuitureResearch, 27, 531-538
Aquaculture Research, 1996, 2 7 , 531-538
Fish meal/soya meal ratios in Colossoma diets M B van der Meer et al.
Table 1 Diet composition expressed in per cent of dry matter
Experiment 1
Experiment 2
Diet
1
2
3
4
Ingredients
Fish meal
Tankage
Blood meal
Corn meal
Soya flour
Wheat flour
Soya oil
Fish oil
Salt
Premix
49.7
3.4
1.0
44.3
0.0
0.0
0.0
0.0
1,0
0.5
42.2
2.9
0.8
37.6
13.4
0.7
0.4
0.4
1.0
0.5
28.1
1.9
0.6
25.1
38.5
2.1
1.1
1.1
1.0
0.5
11.3
0.8
0.2
10.0
68.6
3.8
1.9
1.9
1.0
0.5
Proximate analysis
Protein
Lipids
Carbohydrates
Fibre
Ash
Energy (kj g-')'
45.9
7.1
28,8
2.8
15.4
18.5
44.3
7.3
29.9
4.0
14.6
18.4
43.5
5.6
32.2
6.9
11.8
17.9
% soya'
Chemical score
Limiting lAA^
0
76.0
lys
15
76.3
lys
43
77.1
lys
5
6
7
8
9
10
0.0
0.0
0.0
0.0
88.7
4.7
2.5
2.5
1.0
0.5
16.6
1.2
0.3
65.2
0.0
8.4
3.4
3.4
1.0
0.5
14.1
1.0
0.3
63.0
4.4
8.6
3.5
3.5
1.0
0.5
9.4
0.7
0.2
58.8
12.9
9.1
3.8
3.8
1.0
0.5
3.8
0.3
0.1
53.8
22.9
9.6
4.0
4.0
1.0
0.5
0.0
0.0
0.0
50.4
29.6
10.0
4.2
4.2
1.0
0.5
43.8
6.0
32.9
7.8
9.6
18.3
42.8
4.7
35.1
9.2
8.6
17.3
22.0
9.1
58.1
3.2
7.7
18.8
21.5
8.9
60.3
2.6
6.7
18.9
22.4
12.6
55.7
3.0
6.3
19.8
22.4
14.1
54.5
3.8
5.4
20.2
19.8
12.8
60.0
2.7
4.7
20.0
77
78.0
lys
100
78.6
lys
0
61.5
lys
15
61.7
lys
43
62.2
lys
77
62.7
lys
100
63.1
lys
' Ingredients: fish meal = brown tuna meal (66.2% protein, 8.8% fat, 0.2% carbohydrates, 4.2% crude fibre, 20.5% ash):
tankage = bone and meat meal: blood meal = mechanically dried; corn meal = pre-cooked white meal: soya flour = solvent
(hexane) extracted (43,7% protein, 5,1% fat, 38.2% carbohydrate, 8.1% crude fibre, 6.8% ash): premix = 'Vitamelk peces A',
Roche S.A., containing per kg: 3,48*10" IU vit A, 0.70*10' IU vit D3, 11 000IU vit E, 2.17 g vit K3, 4.35 g vit Bl, 8.70 g
vit B2, 43.5 g vit B3, 17.4 g pantothenic acid, 4.35 g vit B6, 74 mg vit B8, 1300 mg folic acid: 8.70 mg vit B12: 130 g
vit C, 130 g choline, 17.4 g magnesium, 17.4 g iron: 8.70 g zinc, 2.17 g copper, 435 g iodine, 43.5 mg selenium, 43,5 mg
cobalt.
* Energy content: gross energy content calculated using the following energy values: protein, 23.4 kJ g"'; lipid, 39,8 kJ g"':
and carbohydrates, 17.2 kJ g"' (Cho, Slinger & Bayley 1982),
* % soya, proportion of soya meal in the diet (see text).
* IAA, indispensable amino acid; lys, lysine.
allowed us to test the hypothesis that C. macropomum
uses soya and animal protein equally well.
The biological parameters used to evaluate dietary
protein quality were metabolic ration (MR, g kg"*'"
day^'), metabolic growth rate (MGR, g kg"" May"'),
feed conversion (FC, g dry feed g wet weight gain"') and
net protein utilization (NPU, g protein gain g feed
protein-'* 100).
Feed uptake, growth, feed utilization and body
composition parameters from each experiment were
submitted to a one-way ANOVA. The significance of
differences among diets within experiments were
determined by Tukey-test (Statistix 1990). Trends
©1996 BlackweU Science Ltd, Aquflcuiture Research, 27, 531-538
between the different treatments within each experiment were studied through quadratic regression
analysis: Y = J3,, + j3j*X, + ^/(K)^ + e, where: Y =
average value per treatment; P^, )3j and fi^ = regression
coefficients; X. = the soya proportion in diet i (i = 0,
15, 43, 77. 100). The quadratic component i3/(X,)was only included if it improved the adjusted r^ of the
regression (Statistix 1990).
Body protein content is affected byfishsize (Shearer
1994), which was also shown for C. macropomum
(Gunther & Boza 1993). To separate the effect of body
weight (Wf) from that of diet composition (% soya),
we performed a multiple linear regression analysis;
533
Fish meal/soya meal ratios in Colossoma diets M B van der Meer et al.
Aquaculture Research. 1996. 27, 531-538
protein gave a slight, but not significant, growth
increase in channel catfish.
The lack of significant differences in growth rates
at equal protein levels confirmed the hypotheses that
C. macropomum can grow equally well on soya and on
fish meal protein. In this respect, C. macropomum differs
from carp (Viola et al 1982), trout (Dabrowski et al.
1989), African catfish (Machiels 1987), channel catfish (Mohsen & Lovell 1990) and shrimp (lim & Dominy
1990). which all grew better on fish meal diets. In
African catfish (Machiels 1987) and channel catfish
(Andrews & Page 1974), addition of cristaline amino
acids could not prevent reduced growth with 100%
soya diets. This possibly also indicates that the amino
acid profile of soya was not the cause of its poorer
performance compared tofishmeal in those species.
Both feed conversion (Table 2; Fig. lc) and NPU
(Table 3; Fig. Id) tended to improve with increasing
soya levels in the diet. The feed conversions of 43, 77
and 100% soya diets were significantly lower than
those of the 0% soya diets. However, the NPU of the
100% soya meal diet was only significantly higher
than the 0% soya diet in experiment 2.
P ^ ^ = a + P*{% soya) + Y*(Wf) + e. where; P^^. =
average body protein percentage; a, j3 and y =
regression coefficients; e - error term.
Results and discussion
Feed consumption, growth and feed utilization
No significant differences were found between the MR
of fish fed 0. 15 or 43% soya diets (P > 0.05; Table 2;
Fig. la). However, the MR administrated with the
100% soya diets was significantly lower than the ration
given to the 15 or 4 3% soya diets. The reduced uptake
of diets with more than 43% soya could be caused by a
lower palatability of soya compared to fish meal.
Decreased palatability of diets containing soybean
meal was also reported in salmonids (Lovell 1991).
The growth rates obtained in experiment 1 with
the 45% protein diets (between 60.6 and 67.8 g
kg-08 day"'; Table 2) were comparable to maximum
growth rates reported previously (Giinther & Boza
1993; Van der Meer et al. 1995). The average growth
rate obtained in experiment 2 (44.3 gkg"""day"')
was comparable to growth rates formerly obtained in
our laboratory with similar low protein diets (Van der
Meer e£ai.l995).The43% soya diet tended to promote
better growth than 0 and 100% soya diets (Fig. lb).
However, no significant differences in growth rate
were found between treatments in both experiments.
Mohsen & Lovell (1990) also found that substitution
of about 50% of the fish meal protein by soya meal
Body composition
In both experiments, no significant differences were
found in body protein content between treatments
(Table 3; Fig. le). The regression (P^y = 9.51 +
0.0176*% soya + 0.119*Wf; r^ = 0.62, P < 0.001)
Table 2 Weight increase, feed consumption and feed conversion by experiment and diet*
Fish weight (g fish')
Experiment
Diet
Growth
Feed consumption
Feed
MR
(gkg-0
30
DO
40
SO
60
70
«}
90
too
I to
to
0
>0
20
30
40
10
20
M
40
so
so
so
00
70
so
90
100 n o
%soya
% soya
70
90
100 n o
0
to
10
70
30
40
% Soya
50
60
70
00
80
100 110
%soya
1• 0
0
10
20
X
40
so
flO
70
80
90
100
itO
%soya
Figure 1 Feed uptake, growth, feed utilization and body composition in relation to the soya protein proportion in the diet:
(a) feeding ration; (b) growth rate; (c) feed conversion; (d) net protein utilization; (e) body protein content; (1) body ash content.
X-axis: % soya, proportion of soya meal in the diet (see text); ( • ) experiment 1, 45% protein diets; (D) experiment 2, 20%
protein diets. Numbers near the markers indicate diet numher (seeTable 1); vertical solid lines indicate the standard deviation.
revealed that not only body weight (Wf;Pi-8S.
Statlstix (1990) An Interactive Analysis Program for Microcomputers. NH Analytical Software. St Paul. MN.
Steward Anderson ].. Lail S.P.. Anderson D.M. & McNivenM.A.
(1993) Evaluation of protein quality in fish meals by
chemical and biological assays. Aquaculture 115.305-325.
Tacon A.G.]. (19 8 7) The nutrition and feeding of farmed fish
and shrimp — a training manual. 2 — Nutrient sources
and composition. Field Document 5/E, GCP/RLA/075/ITA.
Food and Agriculture Organisation of the United Nations.
Brasilia.
Van der Meer M.B.. Machiels M.A.M. & Verdegem
M.C.J. (1995) Effect of dietary protein level on growth.
Aquaculture Research. 1996, 2 7 , 531-538
protein utilization and body composition of Colossoma
macropomum. Aquaculture and Fisheries Management 26.
901-909.
Van der Meer M.B. & Verdegem M.C.J. (1996) Comparison of
amino acid profiles of feeds and body protein as a quick
method for selecting promising feed ingredients: a case
study for C. macropomum (Cuvier). Aquaculture Research 27.
487-495.
Viola S.. Mokady S.. Rappaport U. & Arieli Y. (1982) Partial
and complete replacement of fish meal by soybean meal in
feeds for intensive culture of carp. Aquaculture 26. 2 2 3 236.
Viola S.. Zohar G. & Arieli Y. (1986) Phosphorous requirements and its availability from different sources for
intensive pond culture species in Israel. Part I: Tilapia.
Bamidgeh 3 8 . 3-12.
Watanabe T.. Satoh S. & Takeuchi T (1988) Availability of
minerals in fish meal to fish. Asian Fisheries Science 1.175195.
© 1996 Blackwell Science Ltd. AquflCuJtureReseardi. 27, 531-538
538