The Study On Effects Of Dietary LNA, ARA, DHA And EPA Levels On Growth Performace And Immunity Of Juvenile Golden Pompano(Trachinotus Ovatus)

1. Effects of linolenic acid levels on growth performance, digestive enzymes and antioxidant capacity of juvenile golden pompano(Trachinotus ovatus)This experiment was conducted to determine the effects of dietary linolenic acid(LNA) levels on growth performance, digestive enzymes and antioxidant capacity of juvenile golden pompano. The fish [(10.38±0.10) g] were randomly assigned into 6 groups with 3 replicates per group and 20 fish per replicate. Six diets were formulated with six levels of LNA(dry matter, 0.13%、0.59%、1.10%、1.60%、2.10% and 2.50%). Fish were fed twice daily to apparent satiation for 56 days. The results show as follows: Weight gain(WG) and significant growth ratio(SGR) of fish fed diet with 0.59% and 1.10% LNA are significantly higher than group 2.1% and group 2.5%. Viscerosomatic index(VSI), hepatosomatic index(HSI), condition factor(CF), abdominal fat(AF) and survival rate(SR) of fish are significantly affected by dietary LNA levels. The activity of pepsin of fish fed diet with 0.59% LNA is significantly higher than fish fed diet with 0.13% and 2.50% LNA. The activity of amylase of fish fed diet with 1.10% LNA is significantly lower than other groups. The total antioxidant capacity and catalase activity of serum show an increased trend and then decreased with the increasing dietary LNA level. Quadratic regression analysis on SGR indicated that the optimum dietary LNA level for optimal growth of juvenile golden pompano is 1.04% of dry matter.2. Effects of dietary arachidonic acid levels on growth performance, digestive enzyme activities and gut morphology of juvenile golden pompano Trachinotus ovatusThe effects of dietary arachidonic acid(ARA) levels on growth performance,digestive enzyme activities and gut morphology were studied in juvenile golden pompano. Six diets were formulated with six levels of ARA(dry matter, 0.15%, 0.36%, 0.51%, 0.71%, 0.88% and 0.96%). Fish were fed twice daily(06:00 and 17:00) to apparent satiation for 56 days. Weight gain(WG), specific growth rate(SGR), protein efficiency ratio(PER), feed conversion ratio(FCR) and viscerosomatic index(VSI) were significantly affected by dietary ARA levels. WG, SGR and PER increased with the increasing levels of ARA from 0.15% to 0.51%, and thereafter slightly declined. WG, SGR and PER were observed to be the highest in fish fed the diet with 0.51% ARA and the lowest in fish fed the diet containing 0.15% ARA. Linear regression analysis on SGR indicated that the recommended optimum dietary ARA level for optimal growth of juvenile golden pompano was 0.53%. Whole body protein was significantly declined with the dietary ARA levels increased from 0.15% to 0.88%, and reached to the lowest value in fish fed the diet containing 0.88% ARA. The whole body lipid content showed an opposite trend compared with whole body protein. Pepsin activities showed no significant differences among each treatment, while, lipase activities of fish were significantly influenced by dietary ARA levels. The number of goblet cell and intestinal villus length increased with the increasing levels of ARA from 0.15% to 0.51%, and decreased thereafter.3 Effects of dietary DHA levels on growth performance, immunology indexes, antioxidant capacity and ammonia anti-stress ability of juvenile golden pompano Trachinotus ovatusThis experiment was conducted to determine the effects of dietary DHA levels on growth performance, immunology indexes, antioxidant capacity and ammonia anti-stress ability of juvenile golden pompano. The fish [(8.31±0.05) g] were randomly assigned into 6 groups with 3 replicates per group and 20 fish per replicate. Six diets were formulated with six levels of DHA(dry matter, 0.02%、0.45%、1.00%、1.40%、1.90% and 2.40%). Fish were fed twice daily to apparent satiation for 56 days. The results show as follows: WG and SGR of fish fed diet with 0.45% and 1.00% DHA are significantly higher than other group. FCR of fish fed the diet with 0.45% and 1.00% DHA is significantly lower than fish fed the diet with 2.40% DHA. Survival rate is not significantly affected by dietary DHA levels. Whole body protein is significantly increased with the dietary ARA levels increased. Whole body lipid shows an increased trend and then decreased with the increasing dietary DHA levels. Whole body ash content showed an opposite trend compared with whole body lipid. The content of malondialdehyde(MDA) is increased with the increasing dietary DHA levels, and then thereafter decreased, and SOD of liver shows an opposite trend compared with MDA. The optimal amount of dietary DHA for juvenile golden pompano can effectively improve the ability of ammonia anti-stress. Quadratic regression analysis on SGR indicated that the optimum dietary DHA level for optimal growth of juvenile golden pompano is 0.83% of dry matter.4 Effects of dietary EPA levels on growth performance, immunity and antioxidant capacity of juvenile golden pompano Trachinotus ovatusThis experiment was conducted to determine the effects of dietary EPA levels on growth performance, immunity and antioxidant capacity of juvenile golden pompano. The fish [(5.41±0.11) g] were randomly assigned into 6 groups with 3 replicates per group and 20 fish per replicate. Six diets were formulated with six levels of EPA(dry matter, 0.05%, 0.45%, 0.98%, 1.60%, 2.20% and 2.60%). Fish were fed twice daily to apparent satiation for 56 days. The results show as follows: With the increasing level of EPA, WG increased and then thereafter decreased. WG of fish fed the diet with 0.45% EPA is significantly higher than groups containing 0.98%, 1.60%, 2.20% and 2.60% EPA. SGR shows a same trend with WG. FCR is significantly increased with the increasing dietary EPA levels, and the FCR of fish fed the diet with 2.60% EPA is significantly higher than the fish fed the diet with 0.05% EPA. The survival rate of fish is significantly affected by dietary EPA levels. There are no significant influences among each group on whole body moisture, whole body lipid and whole body ash. Lysozyme activity of fish fed the diet with 0.98% EPA is significantly higher than the groups with 0.05%, 0.45%, 2.20% and 2.60% EPA, while, there are no differences among each treatment on Ig M and C4 content of serum. Dietary EPA levels do not significantly affect the antioxidant capacity of juvenile golden pompano. Quadratic regression analysis on SGR indicated that the optimum dietary EPA level for optimal growth of juvenile golden pompano is 0.42% of dry matter.