Growth performance and whole-body composition of yellow catfish (Pelteobagrus fulvidracoRichardson) under feeding restriction

Abstract

Fish growth is an important index in aquaculture practice. However, the effect of growth under restricted feeding on quality of fish grown to the same size remains poorly unknown. In this study, yellow catfish were reared by feeding them at three different feeding rates such as low (FR-L group), medium (FR-M group) and high (apparent satiation) ration levels for 82, 58 and 34 days to reach the same size, respectively. After this period, the growth performance, whole-body amino acid composition and fatty acid profile of the fish were evaluated. Feeding restriction led to significant decreases in specific growth rate and feed conversion efficiency. Significant increases in dry matter, protein and energy contents were observed in fish under both restricted feeding treatments. FR-L-treated fish had significantly lower whole-body essential amino acid contents, and significantly higher Ala and non-essential amino acid contents compared to fish fed to satiation. Fish in restricted feeding treatments had significantly higher n-3 PUFA and n-3/n-6 ratio compared to the fish fed to satiation. The present results indicate that from a quality perspective, there are certain advantages in improvement of whole-body composition and enrichment of n-3 PUFA associated with the restricted feeding of yellow catfish at slow growth rate.