The effect of feeding frequency on growth of Litopenaeus vannamei (Boone) and water quality

The effects of five different feeding frequencies (1, 2, 3, 4 and 5 times per day) on the growth and survival of Litopenaeus vannamei (Boone) and water quality were studied in a 7-week growth trial. The shrimp were held in 15×2.0 m³ indoor tanks. The water management was designed to non-exchange water system. The shrimp (initial weight of 0.24 g) were stocked at a density of 50 animal · m^-3 and fed a pelleted feed, with all the feed being placed on feeding trays. After 7 weeks treatment, the shrimp growth rate and feed conversion ratio increased progressively as feeding frequency increased from 1 to 4 times per day. However, there were no significant (P>0.05) differences between 4 and 5 feeding frequency. The shrimp survival rate was lowest when feeding 1 time per day and highest when feeding 2 times per day and also decreased as feeding frequency increased from 2 to 5 times per day. The feed utilization was the most efficient when fed 3 times per day. There were no significant (P>0.05) differences on some water quality parameters (pH, H₂S, COD and salinity) among treatments. However, the NH₄⁺ and NO₂^- concentrations were higher when feeding frequency from 3 to 5 times per day compared to 1 and 2 times per day.