Optimizing Poultry Meal and Gelatin Concentrations in Feed for Scylla serrata: Effects on Growth, Digestibility, Survival, and Pellet Performance
Role
Co Investigator
Description
This research investigates the effects of varying gelatin and poultry meal concentrations in feed formulations for Scylla serrata (mud crab) through two distinct trials aimed at enhancing pellet performance, growth, digestibility, and survival in aquaculture settings. In Trial 1, the focus is on evaluating gelatin concentrations of 8%, 12%, and 16% to determine their impact on pellet properties and palatability. The diets are carefully formulated to be isonitrogenous (approximately 43% crude protein) and isolipidic (approximately 15% crude lipid), incorporating 9% poultry meal while adjusting soybean meal to balance the gelatin variations. Feed preparation involves grinding dry ingredients—such as fishmeal, soybean meal, krill meal, poultry meal, and wheat flour—to a particle size of less than 500 μm, followed by thorough mixing. Gelatin is dissolved in warm water (50–60°C), combined with the dry mix along with fish and squid oils, extruded through a 10-mm die, and dried to achieve approximately 10% moisture content. The experimental design comprises nine pellet batches (three diets, each with three replicates), which are assessed for dry hardness using breaking force or a subjective scale, softness after rehydration in saline water through water absorption and compression force measurements, storage efficiency over eight weeks by monitoring lipid oxidation (peroxide value) and physical integrity, and palatability based on feed consumption rates observed in nine crabs. Trial 2 shifts the focus to poultry meal concentrations of 0%, 5%, 9%, 15%, and 20%, utilizing diets with 12% gelatin and chromic oxide as a digestibility marker. These diets are formulated by progressively replacing soybean meal with poultry meal to maintain nutrient consistency. The setup involves 150 adult crabs (100–200 g), each housed individually in PVC containers equipped with shelters to prevent cannibalism and fed twice daily at 5% body weight for eight weeks under controlled environmental conditions (25 ppt salinity, 28°C, pH 7.5–8.5, dissolved oxygen >5 mg/L). Data collection encompasses growth metrics including weight gain, specific growth rate, and carapace dimensions, apparent digestibility determined through fecal chromic oxide analysis, survival rates, and, if feasible, additional parameters such as digestive enzyme activities and blood biochemistry. Statistical analysis for both trials employ one-way ANOVA or Kruskal-Wallis tests, with post-hoc analysis conducted at a significance level of p < 0.05 to evaluate differences across treatments. This study aims to develop optimized, sustainable feed formulations to support mud crab aquaculture effectively.
Date
01 Oct 2025 - 30 Sep 2027
Project Type
N/A
Keywords
Mud crab;growth performances;sustainable aquaculture;feed development
Funding Body
JCU Singapore
Amount
0
Project Team
Susan Kueh