Effects of dietary lipid levels on growth performance and body composition of juvenile Erythroculter ilishaeformis.

This study was conducted to determine the effects of different dietary lipid levels on growth performance and body composition of juvenile Erythroculter ilishaeformis. Five hundred and forty juvenile Erythroculter ilishaeformis with average initial body weight of (19.36 ±2. 17) g were randomly divided into 6 groups (group Ⅰ～Ⅳ) with 3 replicates of 30 fish in each replicate. Six groups were fed diets with 0, 2%, 4%, 6%, 8% and 10% fish oil, respectively. EE levels of 6 diets were 2. 07% , 4. 28% , 7. 14% , 9. 26% , 11. 17% and 15. 32% , respectively. The experiment lasted for 60 days. The results showed that, weight gain ratio and specific growth ratio in group Ⅲ were significantly higher than that in groups Ⅰ , Ⅱ , Ⅴ and Ⅵ (P0. 05); feed conversion ratio in group Ⅲ was significantly lower than that in groups Ⅰ , Ⅱ , Ⅴ and Ⅵ (P 0.05); the protein efficiency ratio in group Ⅳ was significantly higher than that in groups Ⅰ , Ⅱ, Ⅴ and Ⅵ (P0. 05). There was no significant difference between groups Ⅲ and Ⅳ in weight gain ratio, specific growth ratio, feed conversion ratio and protein efficiency ratio. The whole body lipid and protein contents were significantly affected by the dietary lipid supplementation levels (P0. 05), while there were no significant effects on body moisture and ash content (P0. 05). Based on regression analysis of the specific growth ratio, feed conversion efficiency, protein efficiency and the crude protein content of body composition, the optimal dietary supplementation levels of lipid were 7. 88% , 8. 12% , 9. 18% and 5. 68% , respectively. It was concluded that the suitable dietary lipid level for the Erythroculter ilishaeformis should be 7. 88% ～ 9. 18% .