Hematological parameters of Nile tilapia (Oreochromis niloticus) fed different oil sources / Parâmetros hematológicos de tilápias do Nilo (Oreochromis niloticus) alimentadas com diferentes fontes de óleo

ABSTRACT

The aim of this study was to evaluate the influence of dietary lipid sources on Nile tilapia (Oreochromis niloticus) hematological parameters. 112 juveniles of Nile tilapia with average initial weight of 50 ± 12g were distributed in 16 tanks with total capacity of 100L each in a totally randomized design with four treatments and four repetitions with seven fish each replicate. Treatments were composed of treatment one - soybean oil; treatment two - fish oil; treatment three - linseed oil; treatment four - olive oil. Experimental diets were semipurified, isonitrogenous (32% crude protein) and isocaloric (3200 kcal gross energy/kg of ration). No difference was found between treatments in hemoglobin rates, number of total erythrocytes and leucocytes differential counting (P>0.05). Fish from treatment one presented higher hematocrit rates compared with treatment two and treatment three (P 0.05). The highest level of mean corpuscular volume was observed in fish from treatment four (P 0.05). Fish from treatment three showed higher levels of mean corpuscular hemoglobin concentration compared with treatment four (P 0.05). Dietary lipid sources can influence the hematological parameters of Nile tilapia (Oreochromis niloticus). It was observed a trend of increased erythropoiesis in Nile tilapia fed diets with high levels of -6 series fatty acid.(AU)

RESUMO

Objetivou-se avaliar a influência das fontes de óleo da dieta sobre os parâmetros hematológicos de tilápias do Nilo (Oreochromis niloticus). Foram utilizados 112 juvenis, com peso médio inicial de 50±12g, distribuídos em 16 caixas com capacidade total de 100L cada, num delineamento inteiramente casualizado com quatro tratamentos e quatro repetições, contendo sete peixes por repetição. Os tratamentos eram constituídos por tratamento um óleo de soja; tratamento dois óleo de peixe; tratamento três óleo de linhaça; tratamento quatro óleo de oliva. As rações eram semipurificadas, isoproteicas (32% de proteína bruta) e isocalóricas (3200 kcal de energia bruta/kg de ração). Não houve diferença (P>0,05) entre os tratamentos quanto ao número e diferenciação de leucócitos, número de eritrócitos totais e níveis de hemoglobina.(AU)