Optimizing Nursery Management in Shrimp farming
In shrimp farming, nursery tanks typically receive shrimp at PL-8 or PL-10 stages. Multiphase systems may stock 5-day-old PLs. Stocking densities range from 15-25 PLs per liter in multiphase and 4-12 in two-phase systems, with survival rates exceeding 95%.
Before stocking, tanks, hoses, and air stones undergo disinfection with 20 ppm sodium hypochlorite, followed by brushing, washing, and drying. Seawater is then filled into tanks, and inorganic fertilizers may be applied. Phytoplankton inoculation can expedite bloom formation when necessary.
PLs undergo acclimation to water pH, salinity, and temperature in 1,000-L fiberglass tanks before transfer to nursery tanks. Feeding is initiated if acclimation exceeds two hours.
During the nursery stage, shrimp receive high-quality starter diets with >40% crude protein content and particle sizes less than 800μ. Larval diets mitigate disease risks. Initially, dried feed is broadcast, then delivered in feeding trays.
Water exchange rates should not exceed 10% daily in the first week to maintain high phytoplankton levels, increasing to 30% thereafter. Tank bottoms are siphoned to remove waste.
Critical in the nursery system is the transfer of juveniles to grow-out ponds, preceded by health and digestive tract checks. Nursery management, including tank preparations such as cleaning, disinfection, and probiotic applications, is essential to prevent Vibrio and Pseudomonas outbreaks. Probiotics are applied during tank preparations and production to optimize survival and reduce disease risks.