Eficiência da suplementação alimentar com Arthrospira platensis na alevinagem do Tambatinga (Colossoma macropomum x Piaractus brachypomus)

Abstract

With the increase in demand for fish and the decrease in supply coming from the extractive fisheries, aquaculture now has a key role in food production, and its growth has been sought to optimize production processes with the rational and sustainable use of resources natural. One of the main costs involved in the production system is used in feed, which is justified by the high value of protein sources needed for the formulation. The food provided and to promote animal growth through weight gain, should also nourish the defense system, and so the fish can withstand the stress caused in cropping systems. Considered a natural additive, seaweed Arthrospira platensis can be used to supplement the rations due to their properties and high protein content, reaching up to 70% of its dry weight and possessing considerable amino acid content. This study aimed to evaluate the efficiency of dietary supplementation with dry flour A. platensis with different levels in diets used in the nursery hybrid tambatinga (Colossoma macropomum x Piaractus rachypomus), through the growth performance, haematological parameters, chemical composition of fillets and feed, coloring fin fish and measurement of water quality parameters. The experimental cultivation lasted 64 days corresponding to the nursery phase. The fry, with initial weight of 3.56 ± 0.02 g, were fed a diet supplemented with two levels (20 and 40%) and a control (commercial feed). During the experiment were performed to monitor the growth performance, water quality parameters, and the end, blood was collected for determination of hematological, coloring analysis of the anal fin and chemical composition of the fillets. Water quality parameters those that are above safe limits are the total ammonia (NH3), Nitrite (NO2-), Nitrate (NO3-), increasing as the higher level of supplementation and phosphate (PO43-) in the treatment with 20%, but They did not cause mortality, where survival was 100%. The zootechnical results final weight, weight gain and feed conversion and feed efficiency were obtained in the treatments of 20 and 40%. In color, the best results were in treatment with 20%, which showed very marked in red color. Hematological parameters were higher in treatments 20 and 40% compared to the control diet, with emphasis on the total number of red blood cells, hematocrit, hemoglobin, white blood cell count and total plasma protein and is higher as the highest level of supplementation. The highest crude protein (CP) in fillets were found in the treatments that received supplementation (20 and 40%). The preferred level for supplementation of diets tambatinga fry was 20% A. platensis flour therefore maximizes the benefits outlined above in relation to production performance, the protein composition of the fillet, the coloring and the immune system, concurrently minimizing costs and maintaining good water quality.