Determining the Importance of Macro and Trace Dietary Minerals on Growth and Nutrient Retention in Juvenile Penaeus monodon

SIMPLE SUMMARY: Knowledge of mineral requirements enables diets to be better formulated. Mineral requirements of black tiger prawns (Penaeus monodon) are not well known compared with other cultured prawn species. To close this knowledge gap, the importance of providing additional sources of twelve minerals in prawn diets were assessed. These minerals are known to be required for optimal growth in other animals and included boron, calcium:phosphorus at 1:1 ratio, cobalt, copper, magnesium, manganese, potassium, selenium, sodium, strontium and zinc. Inorganic forms of these minerals were incorporated into diets and fed to prawns for 6 weeks where their effect on growth performance and mineral concentrations in tissues were determined. This study was able to assess the effect of many minerals by adopting a ‘screening design’ where it was demonstrated that additions of calcium:phosphorus at 1:1 ratio, magnesium, boron, manganese, selenium and zinc to diets for black tiger prawns were important for growth, feed conversion efficiency and nutrient utilisation. Further research is needed to determine the requirement values of the important minerals identified in this study. ABSTRACT: Twelve minerals were screened to identify key dietary minerals important for Penaeus monodon growth. The minerals selected included boron, calcium plus phosphorus (assessed in tandem at a 1:1 ratio), cobalt, copper, magnesium, manganese, potassium, selenium, sodium, strontium and zinc. Twelve purified casein/gelatin-based diets were formulated and contained minerals at two levels: below expected requirements, as attributed by the basal formulation (−) and above expected requirements by adding inorganic minerals (+). The two levels were allocated to dietary treatments in juvenile prawns in accordance with the PB design. A two-level screening analysis was employed where effect of each mineral at level − or + across twelve diets were compared to identify the minerals of importance for culture performance of juvenile prawns. Calcium plus phosphorus (at a 1:1 ratio), magnesium, boron, manganese, selenium and zinc produced the greatest positive effects on weight gain, feed conversion efficiency, biomass gain and nutrient/energy retention. Particularly, boron and manganese significantly increased retention of key macronutrients and energy including gross energy, crude protein and crude lipid. Our study demonstrates the importance of several macro and trace minerals in prawn diets and the pressing need to refine their requirements for P. monodon.