Fontes de óleos vegetais em dietas para lambari-do-rabo-amarelo (Astyanax altiparanae): desempenho produtivo, perfil de ácidos graxos, rendimento e composição de carcaça

• Autor(a) principal: Tavares, Mateus Moraes
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2246
• topic: Ácido eicosapentaenóico; Ácido docosahexaenoico; Ácido araquidônico; n-3/n-6; Perfil de ácidos graxos; Eicosapentaenoic acid; Docosahexaenoic acids; Arachidonic acid; n-3/n-6; Fatty acid profile; CNPQ::CIENCIAS AGRARIAS::RECURSOS PESQUEIROS E ENGENHARIA DE PESCA::AQUICULTURA::PISCICULTURA

The lambari-do-rabo-amarelo (Astyanax altiparanae) is a species native of Brazil, being found from the northeast to the south of the country. The cultivation of this species has attracted the interest of many researchers because it is a fast growing fish, omnivorous and natural reproduction which could become a widely species produced in the country. Moreover, it is a fish with good market acceptance. However, the intensification in the production of this species depends mainly on studies related to feed and nutrition in order to indicate the diet that will provide the greatest development of the animal, without prejudice to its health. Thus, the present study aimed to evaluate the influence of supplementation with different sources of vegetable oils in diets for lambari-do-rabo-amarelo. Was used a completely randomized experimental design with six treatments (canola, corn, linseed, sunflower, olive and soybean vegetable oils) and five repetitions, where 510 fingerlings with 1.82 ± 0.09 g (average weight ± SD) were distributed in 30 circular tanks (100L), regarded as experimental units. Fish were fed with the test diets for a period of 90 days. At the end of the experiment, fish were evaluated for productive performance, body yield indexes, carcass chemical composition and lipid profile of the carcass and liver. Significant difference (p <0.05) in survival (SU) of fish fed with supplementary diets with different vegetable oils was observed. Fish fed with diet containing soybean oil had lower survival rate (94.11%) than fish fed diets containing other vegetable oils. The chemical composition of fish carcass was significantly different (p <0.05) for crude protein content. Fish fed with diets containing linseed oil (59.23%) and sunflower (57.84%) had higher percentages of crude protein in the carcass. The lipid profile of the carcass of the fish was a consequence of the diet consumed. Fish fed with diet containing sunflower, soybean and corn oils had significantly higher concentrations of linoleic acid (18:2 n-6) incorporated into its muscles. Fish fed with diets containing linseed oil had higher concentrations of &#945;-linolenic acid (18:3 n-3) incorporated into their muscles. In fish of all treatments was not detected the presence of arachidonic acid (20:4 n-6). Although no significant difference between them was presented, it was observed the presence of eicosapentaenoic acid (20:5 n-3) and docosahexaenoic acid (22:6 n-3) incorporated into the muscle of fish from all treatments, showing that there is a higher affinity of &#916;6 e &#916;5 desaturase enzymes with fatty acids of n-3 series compared to fatty acids of n-6 series. The largest supply of &#945;-linolenic fatty acid for the fish fed with diet containing linseed oil resulted in a higher n-3/n-6 ratio in the carcass lipid profile compared with fish fed with other diets. In the liver of the animals there was a greater accumulation of linoleic and docosahexaenoic acids, compared to &#945;-linolenic acid. These results confirm the higher affinity of the enzymes &#916;6 and &#916;5 desaturases with fatty acid of n-3 series (&#945;-linolenic acid) decreasing the conversion of linoleic acid to arachidonic acid. These results show that the tested vegetable oils are good sources of fatty acids precursors for the synthesis of eicosanoids and confirm that this species has greater capacity to carry out the desaturation and elongation of fatty acids of n-3 series. For human feeding, the World Health Organization recommends that diets have a ratio of series n-3/n-6 fatty acids of 1:4 to 1:10 to be a quality diet. According to the results observed in this study, we can indicate the use of linseed oil for the lambari-do-rabo-amarelo nutrition in order to increase the incorporation of fatty acids of n-3 serie in their muscles, thus increasing the ratio of series n-3/n-6 fatty acids in the flesh of the fish.