trabalho completo - 52ª Reunião Anual da Sociedade Brasileira de

52a Reunião Anual da Sociedade Brasileira de
Zootecnia
Zootecnia: Otimizando Recursos e Potencialidades
Belo Horizonte – MG, 19 a 23 de Julho de 2015
Tilápia do Nilo alimentada com dieta contendo a microalga Schizochytrium sp.1
Guilherme de Souza Moura2, Sâmela Keila Almeida dos Santos3, Marcelo Mattos Pedreira4, Eduardo Arruda
Teixeira Lanna5, Juarez Lopes Donzele6, Maíra da Silva Almeida7, Marcelo Gaspary Martins8
1
Parte de da dissertação de mestrado da segunda autora, com apoio do CNPq, Alltech Inc., Capes e FAPEMIG.
Pós-doutorando do Programa de Pós-Graduação em Produção Animal – UFVJM, Diamantina, Minas Gerais, Brasil, Bolsista CAPES PNPD. email: [email protected]
3
Mestranda em Zootecnia – UFVJM. Bolsista FAPEMIG. e-mail: [email protected]
4
Professor Adjunto – DZO –UFVM. e-mail: [email protected]
5
Professor Adjunto – DZO – UFV. e-mail: [email protected]
6
Professor Adjunto – DZO – UFVM. e-mail: [email protected]
7
Mestranda em Zootecnia – DZO – UFVJM. email: [email protected]
8
Mestrando em Zootecnia – DZO – UFVJM. email: [email protected]
2
Resumo: Objetivou-se avaliar a composição corporal de juvenis de tilápia do Nilo alimentadas com rações
contendo a microalga Schizochytrium sp.. Foram utilizadas 240 tilápias do Nilo (Oreochromis niloticus),
distribuídas em um delineamento inteiramente casualizado, com quatro repetições, doze peixes por aquário e peso
inicial de 1,33g±0,11. Os alevinos foram alimentados com cinco dietas com a mesma composição nutricional,
sendo a dieta controle isenta de Schizochytrium sp. e as outras quatro com inclusão de 10, 20, 30 e 40g de
Schizochytrium sp./kg-1. Os peixes foram alimentados quatro vezes ao dia até a saciedade, evitando sobras de
alimento. Aos 56 dias de experimento, as tilápias foram abatidas segundo os princípios do Abate Humanitário
descrito na Instrução Normativa nº 3/2000. Os dados de composição corporal foram submetidos a análises
estatísticas utilizando-se o Programa SAS. Posteriormente, os efeitos dos níveis de Schizochytrium sp. na dieta
foram estimados por meio de análise de variáveis e modelo de regressão linear. Foram observados efeito linear para
os níveis de ômega 3, ácido docosahexaenóico (DHA) e relação ômega 6:3 nas análises corporais. Conclui-se que a
inclusão de 40 g de Schizochytrium sp..kg-1 de dieta aumenta a deposição de ômega 3 e DHA, melhorando a relação
ômega 6:3 em tilápias do Nilo.
Palavras–chave: DHA, fitoplâncton, ômega 3, PUFA’s, SP1, tailandesa
Nile tilapia fed with diets containing the microalgae Schizochytrium Sp.
Abstract: Body composition of Nile tilapia juveniles fed with diets containing the microalgae Schizochytrium sp.
was evaluated. With initial weight of 1.33g±0.11, 240 Nile tilapias (Oreochromis niloticus) were distributed in a
completely randomized design with four replications and 20 fish per tank. The tilapias were fed with diets
contained the same nutritional composition, being the control diet free of Schizochytrium sp. and the other four to
include 10, 20, 30 and 40g Schizochytrium sp. /kg-1. The fish were fed four times a day to satiation, avoiding food
leftovers. After 56 days of trial, the fish were slaughtered on the principles of humanitarian described in Instruction
Nº 3/2000. Body composition parameters were subjected to statistical analysis using the SAS program.
Subsequently, the effects of the levels of Schizochytrium sp. in the diet were estimated by analysis of variance and
linear regression model. Linear effect was observed for levels of omega 3, docosahexaenoic acid (DHA) and omega
6:3 ratio in body analysis. It was concluded that the inclusion of 40g of Schizochytrium sp..kg-1 of diet increases the
deposition of omega-3 and DHA, improving the omega 6: 3 ratio of Nile tilapia.
Keywords: DHA, omega 3, phytoplankton, PUFA's, SP1, Thai
Introduction
The fish nutrition has advanced with the expansion of aquaculture in order to achieve better performance
rates. Thus, diets should provide all the nutrients and energy as a way to optimize the fish development. Among the
nutrients, the fatty acids are essential for growth and survival, as well one of the most important sources of energy.
The fatty acids of the omega 3 family are not produced by the fish, requiring supplementation in food. It is
noteworthy that the amount of omega 3 found in freshwater fish and marine are different because the staple food in
both environments (algae), are equal in the amount of lipids, but different in composition. Marine and freshwater
algae have approximately 50% lipids in the form of polyunsaturated fatty acids (PUFA's). However, marine algae
contains higher concentrations of omega 3 than freshwater algae, which has highest concentration of omega 6.
Therefore the level of omega-3 PUFA's family in freshwater fish is low in relation to marine water fish (RIBEIRO
et al., 2007).
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52a Reunião Anual da Sociedade Brasileira de
Zootecnia
Zootecnia: Otimizando Recursos e Potencialidades
Belo Horizonte – MG, 19 a 23 de Julho de 2015
As the body lipid profile can be changed according to diet, the inclusion of omega-3 sources, such as
docosahexaenoic acid (DHA), may increase the levels of this fatty acid in the fish body (Elias, 2014). Thus, the
inclusion of marine algae in diets for freshwater fish may have intended to improve performance and increase the
DHA level in its meat, improving the nutritional value of the product.
Among the algae consumed by fish saltwater, the Schizochytrium sp. has favorable nutritional characteristics
to introduce in fish diets because It has in its composition approximately 25% of DHA. Thus, the body composition
of Nile tilapia juveniles fed with the algae Schizochytrium sp. was studied.
Material e Methods
The trial was conducted at the Laboratory of Aquaculture and Aquatic Ecology of Animal Science
Department, Federal University of Vales do Jequitinhonha e Mucuri, Diamantina - MG.
We used 240 Nile tilapias distributed in a completely randomized design, with five treatments, four
replicates and five fish per tank. The trial was conducted in recirculation system containing 35L tanks, individual
and constant aeration, temperature-controlled, biofiltration and filter ultraviolet (UV). Three times a week, the tanks
were cleaned by siphoning. Once a week the water quality parameters were measured, as follows: temperature, pH,
dissolved oxygen and ammonia.
Fish were fed with five diets contained the same nutritional composition (90% DM, 32% CP, 3100kcal DE,
3.91% CF, 9.7% EE), being used the levels 0, 10, 20, 30 and 40 g of Schizochytrium sp.kg-1 of diet. The tilapias
were fed four times a day (8:00, 11:00, 14:00 and 17:00) until the satiety, preventing food leftovers.
After 56 days the Nile tilapias were slaughtered according the principles of humanitarian described in
Instruction No 3/2000. The fish carcasses were freeze-dried, ground and weighted. Part of the samples of fish and
all experimental diets were forwarded to the Chemical Analysis Laboratory (DZO-UFVJM) for chemical analysis
(dry matter, mineral matter, ether extract, crude protein, calcium and phosphorus). The other part was sent to the
Institute of Food Technology (ITAL- Campinas) for lipid profile analysis.
The body composition data were submitted to statistical analysis using the program Statistical Analysis
System 9.0 (SAS, 2008). Subsequently, the effects of the levels of Schizochytrium sp. in the diet were estimated by
analysis of variance and linear regression model.
Results and Discussion
During the experimental time the recirculation system maintained the water quality within the range
established by Kubitza (2000) for tropical fish. For body analysis (Table 1), the Schizochytrium sp. levels
influenced the body crude protein, which presented quadratic effect (p <0.05) in function of the treatments. The
inclusion of 20g of Schizochytrium sp.kg-1 increased body crude protein of fish at 9.25% compared to the control
treatment. As the dry matter (DM), mineral matter (MM), calcium (Ca), ether extract (EE) and phosphorus (P), no
differences were observed between the levels studied (p> 0.05).
Table 1. Body compositon of Nile tilapia juveniles fed with diets contained Schizochytrium sp.
Nutrients
Levels of Schizochytrium sp. (g.kg-1)
DM (%)
MM (%)
EE (%)
CP (%)1
Total Ca (%)
Total P (%)
1
CV(%)
Control
10
20
30
40
86.86
85.33
85.05
85.35
84.96
1.32
25.55
30.03
25.89
26.98
26.95
6.76
19.81
19.95
20.08
19.94
22.10
5.32
56.22
59.34
59.56
56.82
55.88
1.12
5.15
5.09
4.11
5.86
5.36
18.05
3.99
3.06
3.66
3.99
3.81
22.39
2
2
Quadratic effect (p<0,05): Y= 52,9932 + 4,42371X – 0,7908X ; R = 0,79
For the analysis of body fatty acids, the inclusion of Schizochytrium sp. in the diet promoted linear effect
(p <0.05) in the levels of DHA, omega 3 and omega 6:3 ratio. There was no effect compared to other fatty acids
with inclusion levels of Schizochytrium sp. in the diet (Table 2).
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52a Reunião Anual da Sociedade Brasileira de
Zootecnia
Zootecnia: Otimizando Recursos e Potencialidades
Belo Horizonte – MG, 19 a 23 de Julho de 2015
Table 2. Fatty acids profile of Nile tilapia fed with diets contained Schizochytrium sp.
0
32.91±0.57
36.57±0.50
22.30±0.95
Levels of Schizochytrium sp. (g.kg-1)
10
20
30
34.24±0.41 34.23±0.19 32.55±0.6
35.53±0.21 36.21±0.11 34.93±0.64
22.52±0.55 22.18±0.28 24.43±0.92
40
33.32±0.04
33.64±0.14
25.46±0.28
20.50±1.04
19.21±0.97
1.29±0.07
20.27±0.54
18.95±0.52
1.31±0.69
18.64±0.26
17.50±0.27
1.14±0.02
20.22±0.79
19.10±0.77
1.12±0.03
20.22±0.26
19.31±0.05
0.91±0.02
1.80±0.24
1.07±0.04
0.67±0.25
11.39±1.39
2.26±0.07
1.02±0.05
1.24±0.07
8.97±8.55
3.54±0.1
0.96±0.03
2.59±0.09
5.26±3.23
4.21±0.14
1.11±0.04
3.10±0.11
4.80±5.88
5.25±0.12
1.14±0.14
3.95±0.14
3.85±1.59
Fatty acids (%)
Saturated
Monounsaturated
Poliunsaturated
Omega 6
Linoleic
Arachidonic
Omega 3a
Linolenic
DHAb
Omega 6:3c
CV (%)
1.43
0.99
2.47
3.09
3.02
13.85
1.38
2.10
5.54
6.43
a
Linear effect (P<0.05): Y=0.756500 + 0.884500X; R2= 0.98
Linear effect (P<0.05): Y= -0.229000 + 0.845000X; R2= 0.98
c
Linear effect (P<0.05): Y=12.6425 – 1.92850X; R2= 0.91
b
The levels of omega 3 and DHA body were increasing in function of the inclusion of algae in the diet. The
tilapias fed with 40g of Schizochytrium sp..kg-1 of diet presented 2.92 and 5.9 times more omega-3 and DHA,
respectively, than those that ingested the control diet.
With the inclusion Schizochytrium sp. were observed improvement in the relationship omega 6 and omega
3. According to the Food and Agriculture Organization / World Health Organization (FAO / WHO, 2008), the ideal
relationship between these fatty acids in food is 5: 1, values close to those presented when added 20g
Schizochytrium sp. or more in the diet.
According to the results, the lipid profile of tilapia can be modified depending of the ingredients used in
the diet composition. The different levels of inclusion of algae Schizochytrium sp. provided different lipid profiles,
which can be explained by the composition of polyunsaturated fatty acids present in this algae, mainly omega 3
family.
Conclusions
It was concluded that Nile tilapia fed with diets containing 40g of Schizochytrium sp.kg-1 presents higher
deposition of Omega 3 and DHA body.
Acknowledgements
We would like to thank the Alltech Inc, CNPq, FAPEMIG and CAPES for financial support.
References
ELIAS, M.F. 2014. Lipídios Nutricionais Oportunidade para as Indústrias com Benefícios para a Sociedade.
Revista Fi South American, 16:77-78.
STATISTICAL ANALYSIS SYSTEM – SAS. User´s guide: statistics. Version 9.0. Cary: SAS Institute inc., 2008.
FAO. Food and Agriculture Organization. 2008. Interim Summary of Conclusions and Dietary Recommendations
on Total Fat & Fatty Acids. From the Joint FAO/WHO Expert Consultation on Fats and Fatty Acids in Human
Nutrition, WHO HQ, Geneva, 10-14.
RIBEIRO, P.A.P.; BRESSAN, M.C.; LOGATO, P.V.R.; GONÇALVES, A.C.S. 2007. Nutrição Lipídica para
Peixes. Revista Eletrônica Nutritime, 4:436-455.
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