Investigation of optimum pantothenic acid level in the feeds for post-larvae fleshy prawn, Penaeus chinensis

The present study assessed the dietary requirement of pantothenic acid (PA) for fleshy prawn (Penaeus chinensis) post-larvae. Five experimental diets were formulated by supplementing different levels of PA as 0, 100, 200, 300 and 400 mg kg−1 diet (designated as P0, P100, P200, P300 and P400, respectively). Triplicate groups of 50 prawns (initial mean body weight: 3 mg) per treatment were fed for 40 days. Prawns fed with P100 diet showed significantly higher (p < 0.05) growth and feed efficiency performance than P0 group. Survival rates in all PA supplemented groups were significantly higher (p < 0.05) than P0 group. However, treatments containing PA > 200 mg kg−1 demonstrated a negative trend with increasing PA levels. Upsurge of hepatopancreatic PA level was observed with increasing dietary PA level, just as P100 and P200 groups contained significantly higher (p < 0.05) hepatopancreatic PA levels than P0 and P400 groups. Meanwhile, prawns fed P200 diet showed significantly higher (p < 0.05) acyl-coenzyme A binding protein gene expression level than P0 group. Consistent with previous fatty acid binding protein gene expression level in P100 and P200 groups were significantly higher (p < 0.05) than that of P0 group. The gene expression of target of rapamycin showed no significant difference (p > 0.05) among the groups. Blasenzellen cell counts per tubule in prawn hepatopancreas were significantly higher (p < 0.05) in P100 group compared to P0 group. Similarly, compared to P0 group, fibrillar cell and resorptive cell count per tubule was significantly higher (p < 0.05) in P100 and P200 groups. When analyzing amino acid profiles, cysteine level in all the PA supplemented groups were significantly lower (p < 0.05) than that of P0 group. Histidine, serine and tryptophan levels in P200, P300 and P400 groups were significantly lower (p < 0.05) than that in P0 group. Isoleucine, methionine and threonine levels in P300 group was significantly higher (p < 0.05) than that in P0 group. Valine level in P400 group was significantly lower (p < 0.05) than that in P0 group. By the broken-line regression, optimum dietary PA requirements for fleshy prawn post-larvae were 93-123 mg kg−1 based on specific growth rate and whole-body PA level.