Uso de dietas fermentadas, usando o conceito aquamimicry, no desempenho zootécnico e econômico de Penaeus vannamei

Abstract

Currently, half of the fish consumed worldwide comes from aquaculture, since fishing is practically stagnant. This sector is growing and tends to continue on the rise, since fish is a food of interest, has differentiated nutritional value, having in its composition relevant amounts of proteins, vitamins and minerals. In addition, they exhibit polyunsaturated fatty acids, which are related to beneficial effects on human health, further stimulating the intake of this food. Brazilian aquaculture is described for being constituted mostly by fish farming, with tilapia being the main species, and by mariculture, in which the cultivation of Penaeus vannamei is the highlight. When it comes to shrimp farming, Ceará is responsible for almost half of the national production. In aquaculture, in general, one of the biggest expenses is with the feed offered to the cultivated organisms. Thus, lately, alternatives have been sought to reduce this expense of crops, for example, the replacement of part of the feed. An alternative adopted in some countries in shrimp farming is the protocol called Aquamimicry. In it, the growth of natural food for shrimp is stimulated, in addition to reports of possible beneficial effects on the general condition of the animal. Thus, the objective of the present work was to evaluate the zootechnical performance of P. vannamei, using the Aquamimicry protocol and performing the partial/total replacement of commercial feed by fermented feed, consisting of fermented soybean meal and wheat bran (70/30), and the total replacement of the feed by a formulated feed. The experiment was carried out at Fazenda Nordeste Aquicultura e Piscicultura S/A, located in Limoeiro do Norte, Ceará. The shrimp in the control diet showed better values of weekly growth, production, survival and FCA than those of the treatments. The replacement of 50% of the ration, T-01, resulted in the same productivity and final average weight as the control. The fermentation process increased the protein content of the treatment diets by about 10%. The water quality parameters did not differ between the control and the treatments. The fermented diets, even with lower values than commercial rations, caused losses in T-02 and T-03. T-01 showed a profit, but lower than the control. In the investment payback time projections T-01 presented 7.2 years and control 3.8 years. This time was shorter, 3.3 years for T-01 and 2.5 years in another scenario, using current shrimp sales values. Although the present work did not obtain results as promising as those expected with the replacement of commercial feed by fermented diets, using the aquamimicry protocol, feed costs are the most relevant in crops and, therefore, it is necessary to search for alternative sources that reduce these costs.