Substituição da farinha de peixe pelo farelo de soja em dietas para juvenis co camarão branco, Litopenaeus vannamei, suplementadas com aminoácidos.

Abstract

In marine shrimp feeds, one of the main sources of protein is fishmeal. This work aimed to evaluate the zootechnical performance of juvenile shrimp L. vannamei. Initially, a basal diet containing 18.00% fishmeal (% of diet, as is basis) and 20.02% soybean meal was formulated. From the basal diet, three other diets were designed, reducing the dietary inclusion of fishmeal to 12, 6 and 0%. Diets were balanced to be isonitrogenous and isocaloric, with the supplementation of the crystalline amino acids DL-Methionyl-DL-Methionine, L-Lysine, L- Threonine, L-Tryptophan and L-Arginine. A total of 330 shrimp of 4.46 ± 0.73 g were transferred to 22 tanks of 61 L each at 75 shrimp/m2 (15 shrimp per tank). Shrimp were fed daily ad libitum at 08:20 am, 01:00 pm and 04:00 pm. After 93 days of rearing, water salinity, pH and temperature reached a mean (± SD) of 29 ± 4 g/L (n = 180), 7.2 ± 0.3 (n = 180) and 27,7 ± 0.6°C (n = 180). Final shrimp survival reached 87.0 ± 7.8% and was unaffected by dietary treatment. Shrimp fed the diet without fishmeal or with 100% substitution achieved a significantly lower final body weight (12.75 ± 0.68 g) compared to those fed other diets. However, no statistical difference was observed in the final body weight of shrimp when fishmeal was reduced by 67%. Gain in shrimp yield, apparent feed intake and feed conversion ratio reached a mean of 561 ± 65 g/m2, 19.7 ± 1.5 g/shrimp and 2.66 ± 0.35. It was not possible to detect statistical differences in parameters (P > 0.05). Results indicated it is possible to replace protein from fishmeal protein from soybean meal by 67% provided that the diets are adequately supplemented with crystalline amino acids, maintain a balance in other essential nutrients and in terms of palatability.