Impacts of microdiet manufacturing technologies on the growth performance of large yellow croaker (Pseudosciaena crocea) larvae

Abstract

Crumbled feed (CF) is the most commonly used microdiet in the weaning phrase of large yellow croaker (Pseudosciaena crocea) in China. However, CF can be inefficient for local hatcheries due to its low water stability. In this study, we evaluated a more water-stable microdiet (micro-extrusion marumerization diet or MM) in comparison to the CF, and ascertained their effects on the growth of larval croaker. Our results showed that the MM (ca. 98% dry weight retained) was much more water-stable than the CF (only 76% dry weight retained) after 5 min vigorous aeration. This was especially true for the preservation of lipid content, 40% of which was lost from the CF. The remaining intact structure and nearly unchanged nutritional composition of the MM enabled greater fish growth performance after a 24-day feeding trail, with 37% more dry weight gained than CF-fed larvae. Additionally, fish body compositions of each treatment directly reflected the nutritional profiles of each diet after aeration, and CF-fed fish had a significantly lower lipid content than those fed the MM (8.97 vs. 15.2%). Our results suggest that MM is a more suitable microdiet for the weaning phrase of croaker in hatcheries with vigorous aeration.

Keywords

• Crumbled feed
• Micro-extrution marumerization
• Microdiet
• Croaker larvae