Effects of feed fat level on growth performance, body composition and serum biochemical indices of hybrid grouper (Epinephelus fuscoguttatus x Epinephelus polyphekadion)

摘要

The growth of teleost fish can be enhanced by several means. A fat-enriched feed provides substantial energy for fish in aquaculture. However, fat is an expensive feed component and one of the highest cost components of the feed for cultured species in the aquaculture industry. Therefore, in recent years, nutritionists increasingly focus on improving the fat efficacy of feed components utilized in commercial feeds. To achieve this, precise, comprehensive, and homogeneous analytical procedures are required to quantify fat in feed components. This study assessed the influence of the feed fat level on growth performance, body composition, and serum biochemical indices of the 8 weeks old juvenile hybrid grouper (8 cm) with average body weight of 7.2 g. The results show that the level of feed fat has no substantial effect on the survival rate of the hybrid grouper, which indicates that hybrid grouper juveniles can tolerate high feed fat levels. In addition, the results also show that increasing the level of feed fat can increase the growth rate of fish and feed efficiency, while decreasing their ammonia nitrogen excretion rate. The suitable dietary fat level of hybrid grouper was identified to be 9.72-10.28%. This offers valuable insight into the effects of the feed fat level on the growth performance of the hybrid grouper, which can inform the culture of other species in aquaculture.