Effects of feeding frequency on growth, survival and water quality of rearing tanks of the Indian white shrimp (Penaeus indicus)

The effects of feeding frequency on growth performance, feed conversion ratio and survival of post-larvae Indian white shrimp, Penaeus indicus were evaluated in a 56-day study. The study was conducted in sixteen fiberglass tanks provided with aerated recirculating water with four replicate tanks for each treatment. Twenty post larvae with a mean weight of 1.56 0.02g were hand-counted and stocked into each of the replicate tanks and fed 2, 4, 6 and 8 times a day, respectively. Final body weights were measured significantly lower at 2 and 4 times/day (5.76 0.08 and 5.96±0.15g, respectively) than 6 and 8 times/day (8.54±0.16 and 8.31 0.19g, respectively) treatments (P<0.05). There were significant differences for the Feed Conversion Ratio (FCR) of shrimps fed 6 and 8 times/day with other treatments. The best mean FCR was obtained from the sixth daily-feeding (P<0.05). The Specific Growth Rate (SGR) of shrimps fed 6 times/ day was significantly (P<0.05) higher (3.03 0.04%) than shrimps fed with all other feeding regimes, while shrimps fed 8 times/ day had a higher SGR (2.95 0.05%) than shrimps fed 2 times/day (2.36 0.06%) and 4 times/day (2.39 0.11%). Survival rate was significantly different (P<0.05). The best mean survival rate was obtained from 6 times/day feeding (P<0.05). There were significant differences for survival rates (P<0.05). The water quality parameters (salinity, dissolved oxygen and temperature) were not different among treatments. However, some water quality parameters (ammonium, nitrate, nitrite, phosphate and pH) were significantly different among the treatments. Results suggested that there was an advantage in feeding P. indicus more frequently than 4 times per day