Use of a mixture of vegetal (Jatropha curcas) and animal (fish silage) byproducts as protein source in shrimp (Litopenaeus vannamei) diets

Abstract

This study evaluated growth responses of white shrimp Litopenaeus vannamei by testing different combinations of Jatropha curcas kernel meal (JCK) and tilapia waste silage (FS) as dietary protein sources under laboratory and pond conditions. A reference diet (RD) based on fish meal was elaborated to contain 35% crude protein and 434 kcal/g; then, five isoproteic and isoenergetic experimental diets were formulated from RD with different FS/JCK proportions as follows: 75%FS/0%JCK; 56.25%FS/13.25%JCK; 26.5%FS/30.89%JCK; 18.75%FS/39.75%JCK; and 0%FS/53%JCK. For the laboratory trial, shrimp (2.90 g) were stocked at 10 m2 in an indoor recirculating system during 90 days. There were differences among the growth parameters of diets. Mean weight gain fluctuated from 6.71±0.61 g observed for the shrimp fed the 75%FS/ 0%JCK diet, to 9.70±0.61 g for the group fed the RD. The RD and 18.75%FS/39.75%JCK diet obtained the highest mean final weight (above 12 g), weight gain (above 9 g), and specific growth rate values (above 1.6%/day). Average final survival was 90.97%. The RD and 18.75%FS/39.75%JCK diets were used for the pond trial. Shrimp (0.49 g) were stocked at 10 m2 within 1-m3 cages into the pond for 35 days. Weight gain (3.47 g) and survival (93.33%) of shrimps were similar between the diets. Quadratic equations with the laboratory data indicated that the maximum responses for growth parameters correspond to FS and JKC inclusion levels in the range of 27.83 to 29.00%, and 32.25 to 33.64%, respectively. A combination of 18.75% FS/39.75%JCK meals as protein source is a potential alternative to effectively substitute FM in practical diets for L. vannamei at the studied ages under both laboratory and pond conditions