The effects of variation in feed protein level on the culture of white shrimp, Litopenaeus vannamei (Boone) in low-water exchange experimental ponds

The present study was conducted to evaluate the effect of varying dietary protein level on pond water quality and production parameters of white shrimp Litopenaeus vannamei (Boone). Experimental units consisted of nine 400-m(2) earthen ponds with a low water exchange. Two treatments were tested: treatment HP consisted of shrimp fed a high-protein diet (40%) during the whole grow-out, and treatment LP consisted of the use of a low-protein diet for the complete farming period. No differences on any of the water quality parameters were observed among treatments. Excellent survival (over 85%) and feed conversion ratios (around 1.6), and acceptable growth (over 12 g) and biomass (from 1721 to 1793 kg ha(-1) ) were recorded in all experimental ponds. No significant differences in any of the production parameters were found among treatment groups.