Although the production cycle of shrimp is relatively short, nutritional and physical property requirements of food are rapidly changing. Rearing protocols are different among hatchery, nursery and grow-out regarding diets and environmental factors. At the hatcheries, shrimp are fed with premium feed with high nutritional composition and quality. Water quality, microbiology, and pathogens are controlled at optimal levels for animals to grow. At the grow-out phase, shrimp are exposed to vulnerable environments in ponds where both the physical (i.e., temperature, pH and oxygen) and biological (i.e., bacteria, live food, and pathogen) factors differ from the hatchery tank condition. Also, grow-out diets often offer lower nutrients than hatchery diets. Hence, the nursery period plays an important role as a transfer phase from hatchery to grow-out, where the postlarvae continue developing their body and get adapted to the vulnerable rearing conditions.
Previous studies on other species reveal that adverse environmental conditions (including nutrition) during critical early development stages may have long-term effects on the performance of animals in the later stage. In this study, we investigated how the diets in the nursery stage affect shrimp in the nursery stage and in the subsequent stage, grow-out. The experiment had two phases: (i) Phase 1: from post-larvae 12 (PL12) to 1.5 g juvenile. In this phase, shrimp were fed with five commercial nursery diets; (ii) Phase 2: when shrim achived 1.5 g, they were restocked and switched to a commercial grow-out diet. All shrimp in the five groups fed with five different nursery diets in Phase 1 were switched to the same grow-out diet in Phase 2. The trial shows that the nutritional and physical properties of the diets exert not only immediate effect during the corresponding rearing stage (nursery) but also their impact can be experienced during the later stages (grow-out) indicating that lifestart sets life performance.