Boosting hatchery success: effective live feed and microdiet protocols for larval rearing efficiency

Abstract

The use of rotifers and Artemia as live feed has supported the growing aquaculture industry, yet gaps remain in understanding larval nutrition. This study aimed to optimize live feed enrichment and microdiet protocols to enhance nutrient delivery and growth and reduce deformities in gilthead seabream larvae. To optimize n-3 HUFAs in total lipids (TLs) and phospholipids (PLs) of Artemia and rotifers, we investigated various factors including temperatures, enrichment doses (Multigain, BioMar), and enrichment duration. Enrichment time and dose are the most important factors for DHA enrichment in both TLs and PLs. To achieve elevated DHA levels in PLs, prolonged enrichment (> 18 h) was recommended with 2 g Multigain/million Artemia , and 0.2 g Multigain/million rotifers. Parallel to enhancing live feed nutritional quality, we investigated the effect of microdiets (ProStart BioMar, PS) feeding protocols on seabream larvae development. Larvae from the EP (Early&Prolonged) group, which start feeding PS at 3 dph, showed significantly higher activities of aminopeptidase N and chymotrypsin compared to those in the P group (start feeding at 15 dph), which suggests that larvae with early cofeeding of PS demonstrated an earlier developed digestive system. Prolonged cofeeding with PS has shown significantly better results compared to weaning with a standard diet in terms of larvae dry weight and deformity rate. Doubling the amount of Artemia during the co-feeding weaning period did not compensate for growth, deformity rate, or production cost. Early and prolonged cofeeding with PS was the most cost-effective protocol.

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