Comprehensive effects of cyclic starvation and refeeding on juvenile grass carp: growth, meat quality, enzyme activity, enteritis, and challenge by Aeromonas hydrophila.

Abstract

Grass carp is the most widely farmed freshwater species globally, but its long cultivation cycle limits commercial production. Compensatory growth offers a strategy to accelerate growth and reduce costs. This study investigated the effects of cyclic starvation-refeeding on juvenile grass carp. Fish subjected to 1 day of starvation followed by 6 days of feeding exhibited super-compensatory growth and significantly higher final body weight than continuously fed controls. No adverse changes were observed in muscle texture or amino acid content. Histology analysis showed no damage to intestinal villi, while digestive enzymes (amylase, lipase, trypsin) significantly increased in the 1-2 day starvation groups. Most immune indicators remained stable, although IL-10 expression increased and TNF-α, IL-8, and IL-15 levels decreased. Notably, resistance to Aeromonas hydrophila was maintained. These findings suggest that short-term cyclic starvation is a safe and efficient approach to improve growth performance without compromising product quality, providing a promising model for innovative aquaculture practices.