Dietary protein requirement of white shrimp, Penaeus vannamei (Boone, 1931) juveniles, reared in inland ground water of medium salinity

A 60-day feeding trial was conducted to evaluate the effect of dietary protein level on growth, digestive enzymes and haemato-biochemical responses of Penaeus vannamei juveniles in inland ground saline water (IGSW) of 15 ppt salinity. The acclimated shrimp (avge. wt., 4.03 +/- 0.05 g) were randomly distributed into seven groups, viz. TCP20, TCP25, TCP30, TCP35, TCP40, TCP45 and TCP50, in triplicate with the stocking density of 15 shrimp per tank (275 L). Seven semi-purified hetero-nitrogenous (200-500 g crude protein/kg), iso-caloric (396 Kcal DE/100 g) and iso-lipidic (60 g/kg) diets were prepared for feeding the shrimp of respective group four times daily on satiation basis. Results indicated that the highest (p < 0.05) WG and SGR, and the lowest FCR were observed in TCP40 group. But PER and ANPU values decreased significantly (p < 0.05) with increasing dietary protein. Whole-body protein and ash contents varied significantly (p < 0.05) with an inverse relationship. Shrimps of TCP40 group had the highest (p < 0.05) haemocyanin and serum total protein, while TCP20 group showed the highest (p < 0.05) serum glucose. Serum cholesterol and triglyceride increased significantly (p < 0.05) with increasing dietary protein level up to 400 g protein/kg and beyond that these decreased gradually. Protease activity increased with increasing dietary protein level, but amylase activity showed an inverse trend. Second-order polynomial regression analysis in relation to WG, SGR and FCR indicated that 393.0-397.90 g protein/kg diet could be optimum for culture of P. vannamei juveniles in IGSW of 15 ppt salinity.

Automated summary

The study investigated the impact of dietary protein levels on the growth, digestive enzymes, and haemato-biochemical responses of Penaeus vannamei juveniles in inland ground saline water. The results showed that a diet with 400g protein/kg led to the highest growth performance, while higher protein levels resulted in increased proteinase activity and decreased protein efficiency ratio.