Manioc ( (Maninhot esculenta) ) and corn mays), alternatives feeds for (Zea mays matrinxã ( (Brycon amazonicus) ) cage rearing in Amazon floodplain lakes Heitor Martins-Jr Jr; Rodrigo Roubach; ; Levy C. Gomes; Edsandra C. Chagas & José Nestor P. Lourenço European Aquaculture Society & World Aquaculture Society Aqua 2006 9-13 May 2006, Florence, Italy
Introduction Cage culture in floodplain lakes as a public demand towards alternatives to augment local fisheries; Need for fish feed alternatives, at smaller costs, so that traditional communities can practice cage fish farming, using lakes and rivers resources; Manioc (Manihotsculenta) possess large agricultural production (637.547 ton./year) and corn (Zeamays) has smaller production (14.700 ton./year) in Amazonas (SEPROR, 2003). Besides fish, it s the alimentary base for riverine communities in Amazon.
Objective To evaluate the substitution of 25 and 50% of a commercial feed (28% crude protein) with manioc and corn in feeding matrinxã reared in cages in an Amazon floodplain lake. 10cm
Materials and Methods Juvenile matrinxã (100.1g ± 28.2 g; 19.3cm ± 1.6cm) were raised in nine cages (6( 6 m 3 ) at a density of 25 fish/m 3, during a period of 90 days in Ariauzinho lake; Fed at a rate of 5% of their biomass for 6 days/week; Feed protocols tested: TC TE-25% TE-50% commercial diet (28%CP) 100% 75% 50% corn 0% 12.5% 25% manioc 0% 12.5% 25%
Materials and Methods Temperature and dissolved oxygen were monitored three times a week; Water ph, hardness and alkalinity measured every two weeks; Monthly, 15% of fish were captured from each cage, to evaluate the growth in weight and length; At the end of the experiment we evaluated: survival, production, weight gain, feed conversion rate, specific growth rate and condition c factor; Statistical Analisys»»»» Anova (p=0.05).
Results Water quality at Lake Ariauzinho. In-cage morning dissolved oxygen (DO) and water temperature during matrinxã (Brycon amazonicus) culture in cages for 3 months at Lake Ariauzinho, Iranduba, AM, Brazil. DO (mg/l) 6 5 4 29,5 29 Temperature (ºC) 3 28,5 2 28 1 0 27,5 0 30 90 Dias de criação 60
Results In-cage morning water ph, hardness and alkalinity during matrinxã ( (Brycon amazonicus) ) culture for 3 months at Lake Ariauzinho, Iranduba,, AM, Brazil. Parameters ph Hardness Alkalinity means ± SD 6.27 ± 0.26 units 23.77 ± 4.87 mg/l 25.85 ± 4.16 mg/l
Results Fish growth in weight (g) Weight (g) 250 200 150 TC TE-25% TE-50% a a a a b b 100 50 a a a a a a 0 30 60 90 Days of experiment * means followed by different letters are significantly different t at p < 0.05 by T-test. T
Results Fish growth in standard length (cm) Standart length (cm) 25 20 a a a a a a a b b a a a TC TE-25% TE-50% 15 0 30 60 90 Days of experiment * means followed by different letters are significantly different t at p < 0.05 by T-test. T
Results Weight gain (g)/fish Weight gain (kg)/m 3 Feed Conversion Rate/FCR Condition Factor Specific Growth Rate Survival (%) Production (kg/m 3 ) Production Parameters Table 1. Matrinxã ( (Brycon amazonicus) ) mean production parameters during a 3 month rearing with alternative feeding in cages at Lake Ariauzinho, Iranduba, AM, Brazil. Parameters TC TE-25% TE-50% 142.2 ± 16.5 a 3.74 ± 0.01 a 2.5 ± 0.06 a 1.482 ± 0.03 0.67 ± 0.07 98.9 ± 1.92 6.0 ± 0.15 a 117.3 ± 1.3 b 2.95 ± 0.03 b 3.2 ± 0.35 b 1.489 ± 0.02 0.40 ± 0.26 98.0 ± 3.46 5.3 ± 0.17 b 112.6 ± 2.1 b 2.67 ± 0.02 b 3.4 ± 0.36 b 1.496 ± 0.04 0.45 ± 0.11 96.6 ± 4.16 5.1 ± 0.21 b * means followed by different letters are significantly different t at p < 0.05 by T-test. T
Results Economy analysis The analysis considered the sale price of the commercial feed (0.52 US$/kg), of the manioc (0.11 US$/kg), and of the corn (0.21 US$/kg) during may m 2006, in Manaus, AM, Brazil. Tested Treatments Economical indicators TC TE-25% TE-50% Amount of feed for 90 days of culture (kg) 56 55.5 54.7 Cost of the ration (US$/kg) 0.52 0.42 0.33 Save (%) on TC 0.0 18.2 36.4 Feed cost after 90 days of culture (US$) 28.92 23.23 17.81 Cost of feed/kg of fish yield (US$/kg) 1.28 1.25 1.11 Profit (%) on TC 0.0 2.54 13.82
Discussion Low water oxygen levels might have influenced the feed conversion (2,5 to 3,4) reflecting also in the final fish weight (Jobling, 1994). One of the main risk factor for cage fish production in Amazonian flood plain lakes (Gomes et al 2006); Fish feeding represents one of the main factors in production and a your costs can reach among 50 to 80% of the investments (Pereira-Filho Filho, 1995a; Melo et al. 2001; Gomes et al 2005), then a 13.8% economy (TE- 50%) is significant; Other works with alternative feeds (fruits, wild or cultivated vegetables), despite their cheaper price, resulted in inferior growth g rates when compared with balanced fish feeds (Reis, 1985; Mori,, 1993; Roubach & Saint-Paul, 1994, Pereira-Filho, 1995b; Araújo jo-lima & Goulding, 1998; Martins-Jr et al. 2004).
Conclusion Results indicated that a 50% commercial feed substitution with manioc and corn has positive effect in production costs; However fish yield is higher with 100% commercial feed; Therefore a 50% substitution of the commercial feed would be oriented for subsistence fish culture in riverine communities.
References ARAÚJO-LIMA, C.; GOULDING, M. Os frutos do matrinxã: ecologia, conservação e cultivo na Amazônia. Brasília/DF: Sociedade Civil Mamirauá/CNPq, 1998. 186 p. BATISTA, V. S.; INHAMUNS, A. J.; FREITAS, C. E. C.; FREIRE-BRASIL, D. Characterization of the fishery in river communities in the Low-Solimões/High-Amazon Region. Fisheries Management and Ecology, London, v.5, p.419-435, 1998.[ GOMES, L. C.; CHAGAS, E. C. MARTINS-JR, H.; ROUBACH, R. ; ; ONO, E. A.; LOURENÇO, N. 2006. Cage culture of tambaqui (Colossoma macropomum) in a central Amazon floodplain lake. Aquaculture, 253: 374 384. JOBLING M. Environmental factors and growth: 155-168. In: Jobling, Chapman & Hall (Ed.). Fish Bioenergetics. London: Fish and Fisheries Series 13, 1994. 309p. IBAMA. Portaria n 03/05. 1p., 2005 MARTINS-JR, H.; ROUBACH, R. ; GOMES, L. C.; CHAGAS, E. C. ; ONO, E. A.; LOURENÇO, N. P. Mandioca e milho, na piscicultura de subsistência do tambaqui em tanques-rede, na várzea da Amazônia. Aquimerco, 2004. MELO, L. A. S.; IZEL, A. C. U.; RODRIGUES, F. M. Criação de matrinxãs (Brycon amazonicum) em viveiros de argila/barragens no Estado do Amazonas. Embrapa Amazônia Ocidental, Manaus, Documento Técnicos, n.18, 30p., 2001. MORI, L. A. Estudo da possibilidade de substituição do fubá de milho por farinha de pupunha (Bactris gasipaes), em rações de alevinos de matrinxã (Brycon amazonicum). 1993. 110p. Tese (Mestrado) - INPA, Manaus. PEREIRA-FILHO, M. Nutrição de peixes em cativeiro. In Val, A.L.; Honczaryk, A. (Ed.). Criando peixes na Amazônia. Manaus: MCT/INPA, 1995a. p.61-74. PEREIRA-FILHO, M. Alternativas para a alimentação de peixes em cativeiro. In Val, A.L.; Honczaryk, A. (Ed.), Criando peixes na Amazônia. Manaus: MCT/INPA, 1995b. p.75-82. RAPP-PY, L.; DEUS, C. Base para desenvolvimento sustentado da RDS Piagaçu.INPA, 45p., 2003 REIS, F. J. S. Avaliação da eficiência nutricional da algaroba (Prosopis juliflora) na produção de alevinos de matrinxã. 1985. 38p. Monografia, UFRP, Recife. ROUBACH, R.; SAINT-PAUL, U. Use of fruits and seeds from Amazonian inundated forests in feeding trials with Colossoma macropomum (Cuvier, 1818) (Pisces, Characidae). Journal of Applied Ichthyology, Berlin, v.10, n.2-3, p.134-140, 1994. RUFFINO, M. L., Manejo dos recursos pesqueiros no médio Amazonas. In: Fischer, C. F. (Ed.) Recursos Pesqueiros do médio Amazonas: biologia e estatística pesqueira. Brasília: IBAMA, Coleção Meio Ambiente, série estudos pesca n.22, 2000. 350p. SEPROR Produção por produtos do Estado do Amazonas, 2003
Acknowledgements Project n. 2147/02 Collaborative No.22.02.0419.00 CNPq 520080/2003-3 Travel grant and research fellowship recipient - CNPq
Thank you Rodrigo Roubach DIDAQ SEAP/PR e-mail: roubach@seap.gov.br
Introduction Amazonas state = the consumption of fish is of the largest of the world, more than 600g/person/day in some riverine communities (Batista et al., 1998). The high effort of capture decrease the natural stocks of certain species of fish in some places (Ruffino( Ruffino,, 2002). The fishing is prohibited during the reproductive period (October to February) and in the period of the flood (April to June) the fish accomplish lateral migrations, reducing the fish readiness and increasing the sale prices (IBAMA, 2005). The invigoration of the technology of culture of fish in cage in floodplain lakes is being recently objective of public politics for the government of the Amazonas to supply to crescent it disputes for fish.
The riverine communities are formed by families of low income, that live of the agriculture and of the subsistence fishing (Py-Daniel & Deus, 2003), without conditions to maintain an activity of high costs. In distant places to example of the Amazon ones, the offer of traditional ingredients (fish flour, flour of blood and soy bran) ) and the commercial feed sale is restricted (Pereira-Filho Filho,, 1995a) It is then implicit the need to look for alternatives in the feeding of the fish, at smaller costs, so that traditional communities can c practice the fish farming in cages, taking advantage of the readiness of resources of lakes and rivers in Amazonian. The manioc ( (Manihot sculenta) ) it is the product of larger agricultural production (637.547 ton.) and corn ( (Zea mays) ) has smaller production (14.700 ton.) in Amazonas (SEPROR, 2003). Close to the fish, this is alimentary base of the riverine communities in Amazonian.