Effects of bioflocs on dietary protein requirement in juvenile whiteleg Shrimp,Litopenaeus vannamei

Abstract

A feeding trial was carried out to determine the effects of bioflocs on dietary protein requirement in juvenile whiteleg shrimp, Litopenaeus vannamei. Four bioflocs treatments (BFT) and one control group were managed: BFT fed diets 25% of crude protein (CP) (BFT‐25%), 30% CP (BFT‐30%), 35% CP (BFT‐35%) and 40% CP (BFT‐40%), and clear water control without bioflocs fed with 40% CP (CW‐40%). Triplicate groups of shrimp (initial body weight, 1.3 g) were fed one of the test diets at a ratio of 7% body weight daily for 8 weeks. At the end of the feeding trial, significantly (P < 0.05) higher weight gain and specific growth rate were obtained in shrimp fed BFT‐35% and BFT‐40% compared to BFT‐25% and BFT‐30%. Shrimp fed BFT‐35% exhibited the lowest feed conversion ratio. Significantly higher muscle nucleic acid indices were also recorded such as DNA content in BFT‐30%, RNA content in BFT‐35% and RNA/DNA ratio than that of shrimp fed control. Total protein level in the haemolymph of shrimp fed BFT‐40% was significantly higher than those of shrimp fed BFT‐25% and BFT‐30%. Therefore, the present results demonstrated that, when L. vannamei juveniles were reared in bioflocs‐based tanks, dietary protein level could be reduced from 40% to 35% without any adverse effect on shrimp growth performance, body composition and haemolymph characteristics. [Correction added on 20 May 2015, after first online publication: sentence modified to clarify the reduction in dietary protein level.].

Some Limiting Factors in Superintensive Production of Juvenile Pacific White Shrimp, Litopenaeus vannamei, in No‐water‐exchange, Biofloc‐dominated Systems

“…These results indicate that, under the conditions of this study, increasing the dietary protein content from 35 to 40% did not significantly ( P > 0.05) improve shrimp performance in terms of growth, survival, FCR, and PER. This concurs with Yun et al () who reported significant increase in growth of L . vannamei in biofloc systems as the dietary protein level increased from 25 to 30 to 35%, but no growth difference between 35 and 40% protein diets.…”

“…However, the higher NO 3 ‐N, significantly lower ( P < 0.05) alkalinity, and higher bicarbonate requirement in EXP were the consequence of the higher nitrification activities in that treatment to nitrify the available ammonia (Loyless and Malone ; Ebeling et al ). This positive relationship between dietary protein content and nitrate accumulation has also been reported by Gómez‐Jimenez et al (), Correia et al (), and Yun et al (). The higher PO 4 concentration in EXP was likely due to the higher phosphorus content in the EXP feed (1.45 vs. 1.01%).…”

“…All water quality parameters remained within safe limits for juvenile shrimp throughout this trial (Wickins ; Tsai and Chen ; Cohen et al ; Mishra et al ; Kuhn et al ). Nitrogen input was higher in the RWs receiving the higher protein feed (EXP), which would have resulted in higher ammonia production (Samocha et al ; Yun et al ). This did not translate into significantly different measured TAN and NO 2 ‐N concentrations between treatments, indicating that the heterotrophic and nitrifying bacterial populations were able to efficiently assimilate and oxidize the available nitrogenous waste.…”

Effects of two commercial feeds with high and low crude protein content on the performance of white shrimp Litopenaeus vannamei raised in an integrated biofloc system with the seaweed Gracilaria birdiae

“…Brito et al (2016) recorded increased crude protein levels in shrimp (in whole bodies) reared in integrated biofloc systems. However, Jatobá et al (2014) and Yun et al (2016) did not find significantly different (p > 0.05) results for protein in whole bodies and muscle tissue in juvenile shrimp reared in a biofloc monoculture system and fed diets containing varying levels of protein.…”

“…Correia et al (2014) and Yun et al (2016Yun et al ( ) demonstrated (1999 for white shrimp culture. This variable influences oxygen consumption, molt cycle, growth, survival, feed consumption rates, metabolic rate and ammonia excretion of shrimp, but did not limit the L. vannamei growth, because the performance variables were considered satisfactory for these conditions.…”