Low-cost feed for Penaeus monodon reared in tanks and under semi-intensive and intensive conditions in brackishwater ponds

Abstract

Experimental diets for juvenile Penaeus monodon were formulated incorporating inexpensive indigenous raw materials. Local fish meal and cowpea meal were tested as replacements for imported protein sources and the diets did not contain vitamin and mineral premixes as supplements. Their effect on shrimp growth, survival, and feed conversion ratio were assessed under laboratory conditions. Best weight gain, specific growth rate, and feed conversion ratio were obtained in the diet with 75% replacement of protein from imported fish meal with local fish meal. This diet was field-tested in brackishwater ponds at three stocking densities: 5, 10, and 20 shrimp m⁻². Results of two experimental runs in ponds showed that shrimp growth and survival was best at the lowest stocking density (5 m⁻²) and poorest at the highest stocking density (20 m⁻²) when 3% of shrimp became soft-shelled. Net pond production for 2 crops ha⁻¹ year⁻¹ were 1.87, 2.58, and 3.66 t ha⁻¹ at 5, 10, and 20 m⁻² stocking density. Cost-benefit analysis revealed a net return on investment (ROI) of 133, 58, 26% and payback periods of 0.7, 1.6, 4.0 years at stocking densities of 5, 10, 20 m⁻², respectively. The low-cost feed, valued at P17 (US$0.70) kg⁻¹, can effectively support pond production of P. monodon at a stocking rate of 5–10 m⁻².