Different lipid levels in the Pacific white shrimp (Litopenaeus vannamei) nursery in systems grown in super-intensive biofloc systems

Abstract

High stocking densities can decrease growth, feed conversion, and depletion of the shrimp immune system, therefore lipids can serve as a highly energetic source capable of meeting the metabolic demands of cultured organisms. This work aimed to evaluate the influence of different lipid levels (50 g kg−1, 70 g kg−1, 90 g kg−1, 110 g kg−1, and 130 g kg−1 extract ether-EE) in diets of Litopenaeus vannamei post-larvae raised in super-intensive biofloc systems, on growth, antioxidant capacity, and feeding costs. The experimental period lasted 30 days and the shrimp of 0.018 ± 0.001 g (PL 20) were stored (5000 PL m-³) in 20 tanks (50 L) in quadruplicates. Significant differences in water quality were not recorded (P > 0.05). The final weight and weight gain were not affected by the different treatments; however, the lowest survival rates were found in the 110 EE and 130 EE treatments and the 50 and 70 EE treatments had the highest productivity and lowest feeding cost (P < 0.05). Furthermore, no significant differences were found in the antioxidant capacity against peroxide radicals (ACAP) and thiobarbituric acid reactive species (TBARS) results (P > 0.05), which might be related to a protective effect proportionated by the biofloc consumption. The quadratic regression for productivity indicated that dietary lipid requirements for L. vannamei nursery is 67.8 g kg−1.