Objective In the early stage of the study, the high-efficient and low-fishmeal compound feed developed by our research group showed good application effects in the aquaculture of small-sized Trachinotus ovatus. The study was conducted to further evaluate the application effect of this feed in the aquaculture of large-sized T. ovatus, to provide some references for practical production.

Method Based on the formula of commercial feed (CK) and high-efficient and low-fishmeal compound feed (test feed), two groups of feed were prepared by feed processing technology and equipment of the enterprise, and large-sized Trachinotus ovatus (125.8 ± 0.70 g) were fed for 95 d. The growth performance, serum biochemical indicators, digestive enzyme activity and muscle quality of each group were compared and analyzed.

Result There was no significant difference in the growth performance, morphological indicators, serum and liver antioxidant performance indicators, and intestinal digestive enzyme activities between the two groups (P > 0.05). However, the daily feed intake, specific growth rate, daily weight gain rate and weight gain rate of the test group T. ovatus were 2.64%, 1.35%, 2.73%, 247.34%, which were 0.21, 0.03, 0.07, 2.25 percentage point higher than those of the control group, respectively, while the feed coefficient that was 0.03 percentage point lower. The levels of total cholesterol (T-CHO), serum triglyceride(TG), low-density lipoprotein cholesterol(LDL-C) in the test group were 0.88, 0.18, 0.30 mmol/L, which were significantly reduced when compared with the control group, while the HDL-C/LDL-C ratio (102.20%) was significantly increased (P < 0.05). In terms of muscle quality, there was no significant difference in muscle protein and fat content as well as amino acid composition (total amino acids, essential amino acids and flavor amino acids) between the two groups (P > 0.05). However, the test feed significantly improved the texture characteristics of the muscle and increased the EPA level in the muscle. Furthermore, compared with the commercial feed, the cost of the test feed was reduced by 8.65%, and the aquaculture benefit was increased by 17.76%.

Conclusion In the aquaculture of large-sized T. ovatus, the high-efficient and low-fishmeal compound feed exhibits similar growth-promoting effects as commercial feed, and it helps to reduce blood lipids, lower aquaculture costs, and improve aquaculture benefits. The above results indicate that the high-efficient and low-fishmeal compound feed can be applied in the entire aquaculture cycle of T. ovatus.