Physical, Chemical and Biological
Evaluation of Commercial Fish Feeds
in Amazonas State
Rodrigo Roubach*,Thais C. Burlamaqui, Eduardo A. Ono,
Manoel Pereira-Filho
Aquaculture Department - CPAQ
Instituto Nacional de Pesquisas da Amazônia – INPA
Manaus, Amazonas, Brazil
European Aquaculture Society & World Aquaculture Society – Aqua 2006
9 - 13 May 2006, Florence, Italy
Introduction
Fish is the most important protein source for human
consumption in the Amazon region;
Tambaqui, Colossoma macropomum, is a high value
fish species and the most representative amongst the
cultured species in the Amazonas state;
Feed is the most expensive single item used in
intensive fish culture systems, representing up to 60%
of fish production cost.
Objetives
Characterize physically and chemically four
commercial extruded fish feeds available in
Amazonas;
Compare the performance of tambaqui, C.
macropomum, juveniles fed with the four
commercial feeds.
Material and methods
Physical characterization
% Dust =
Dust weight/bag (g)
Feed weight/bag (g)
Percentage of feed dust in the bags
x 100%
Material and methods
Physical characterization
% Floatab. =
100 – immerse pellets
% Integrity =
Pellet floatability (30 min)
Physical integrity in the water (30 min)
100
Whole pellets
100
x 100%
x 100%
Material and methods
Physical characterization
Water
absorption =
rate
Wet weight (g)
x 100%
Initial dry weight (g)
Final dry weight (g)
Leaching
x 100%
= 1loss
Initial dry weight (g)
Water absorption rate (10 min)
Leaching loss (10 min)
Means analyzed by ANOVA (p<0.05) and Tukey’s test
Material and methods
Physical characterization
Feed
Particle class weight (g)
x 100%
particle =
Sample weight (g)
size class
Feed ingredients particle sizes
> 850 µm; 500 to 850 µm; < 500 µm
Material and methods
Chemical characterization
Chemical composition - AOAC (1985)
Moisture
Crude protein
Fat
Crude fiber
Ash
Calcium and phosphorus
Results were compared with the information
presented on the feed bag label (guarantee)
Material and methods
Biological evaluation
240 tambaqui, C. macropomum, juveniles of
20 g were distributed in twelve 300 L PVC
tanks supplied with water and aeration
Fish were fed the four diets to apparent
satiation, twice a day, during 60 days
Photo: Jorge Silva
Results and discussion
Physical characterization
Feed 1
Feed 2
Feed 3
Feed 4
24.11
24.49
24.72
24.89
1.47
0.96
0.86
1.16
Floatability 30 min (%) 2
96
100
99
99
Physical integrity 30 min (%)
99
100
99
99
Water absorption rate - 10 min (%)*
340a
270b
389a
344a
Leaching loss - 10 min (%)
1.63a
1.27a
2.95b
1.83a
Parameter
Net weight in the bag (kg) 1
Dust in the bag (%)
2
*Same letters on a row indicate no significant difference (P >0.05)
1 INMETRO 2 ANFAL (National Association of Animal Feed Manufacturers)
Results and discussion
Physical characterization
100%
3.7%
3,0%
3,0%
2,5%
28,2%
29,5%
27,7%
26,2%
90%
80%
70%
60%
50%
34,5%
39,0%
32,3%
34,8%
32,3%
Feed 22
Ração
Feed 33
Ração
Feed 44
Ração
34,2%
35,2%
33,8%
Feed 11
Ração
40%
30%
20%
10%
0%
Feed ingredients particle size class
Perdas
Loss
<<500
500 micras
µm
500<to850
850micras
µm
500
850 micras
µm
>>850
Results and discussion
Chemical characterization
Feed 1
Feed 2
Feed 3
Feed 4
Parameter
Label Anal. Label Anal. Label Anal. Label Anal.
Moisture (max)
13.00
7.50
12.00
7.72
13.00
3.92
13.00
8.19
C. Protein (min) 27.00 22.98 28.00 27.42 28.00 28.91 28.00 29.64
Fat (min)
3.00
6.19
3.50
4.55
3.50
4.74
3.00
4.13
C. Fiber (max)
4.50
4.64
6.50
4.64
7.00
4.76
10.00
6.64
Ash (máx)
10.00
8.52
11.00 11.47
9.00
8.40
14.00
5.41
Calcium (max)
2.00
2.35
3.00
3.00
2.50
1.67
3.00
0.42
Phosp. (min)
1.00
1.37
1.60
1.63
0.80
1.15
0.60
0.81
Art. 45 - Decreto 76.986 Brazilian Ministry of Agriculture Regulation
Results and discussion
Biological evaluation
Parameters
Feed
Weight gain Daily wt. gain
(g)
(g/d)
Feed consum.
(g)
FCR
SGR
1
20.3 ± 2.5
0.34 ± 0.04
1235.6 ± 70.3
3.5 ± 1.1
1.5 ± 0.1
2
20.9 ± 1.1
0.35 ± 0.02
1148.3 ± 16.3
2.7 ± 0.1
1.6 ± 0.0
3
18.0 ± 1.1
0.30 ± 0.02
1175.0 ± 27.2
3.3 ± 0.2
1.4 ± 0.1
4
19.1 ± 2.0
0.32 ± 0.03
1160.0 ± 61.5
3.4 ± 0.2
1.5 ± 0.1
Conclusion
There
are differences in the physical and
chemical characteristics among commercial
extruded fish feeds available in Amazonas;
Pellet
floatability, dust percentage, water
physical integrity and fish weight gain can
be applied by the fish farmer to evaluate
commercial fish feed quality
References
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Acknowledgments
PPI 2-3905/2005 - Estudos do manejo
alimentar e nutrição de tambaqui,
Colossoma macropomum, matrinxã,
Brycon amazonicus, e Pirarucu,
Arapaima gigas.
National Development Council for Research, Science
and Technology of Brazil (CNPq)
Travel grant and research fellowship recipient
Thank you
Rodrigo Roubach
SEAP/PR, Brasília, DF, Brazil
e-mail: [email protected]
www.seap.gov.br
www.inpa.gov.br/cpaq