| Previous studies have shown that golden pompano (Trachinotus ovatus)-high efficiency and low fish meal diet exhibited excellent growth and health in the pond cage culture. To further evaluate the application effect of this feed in deep-sea cage culture, the experimental feed (crude protein 47.66%, crude fat 7.98%) based on the formula feed of low fish meal diet was produced by a feed company with the large-scale production process, and a commercial feed with a well-known brand was used as the control diet (crude protein 47.75%, crude fat 9.63%). Large-sized golden pompano (mean of body weight ~262 g) was cultured with the above two diets in a deep-sea cage (circumference 60 m) for 30 days. The results showed that the growth performance of fish show no statistical difference between the two groups (P > 0.05). However, compared with the control group, the weight gain rate and specific growth rate of fish-fed experimental diets were increased by 14.43 % and 8.19 %, respectively, and the average daily weight gain was increased by 0.68 g. In terms of muscle nutrition and texture characteristics, the muscle lipid contents of the fish-fed experimental diets were significantly high than that of fish-fed control diets (P < 0.05), but the muscle moisture content was significantly decreased (P < 0.05). While the edible quality and texture characteristics of muscle showed comparable between the two groups (P > 0.05). Compared with the control group, the serum protein, triglyceride, total cholesterol, and low-density lipoprotein contents, as well as the activity of aspartate aminotransferase of fish fed the experimental diet were significantly decreased (P < 0.05), and the hepatic total cholesterol content of the experimental group was significantly decreased (P < 0.05). There was no significant difference in liver antioxidant capacity between the two groups (P > 0.05). In addition, the feed cost per 1kg fish of the experimental diet was 18.80 % lower than that of the control diets, and its culture benefit was increased by 62.12 %. The results showed that the experimental diet (high-efficiency and low fish meal diet) not only exhibited an excellent promoting growth, but also improved the muscle fat level and serum lipid metabolism of fish, and the culture benefit. These results indicate that the high-efficiency and low fish meal diet can be applied in the culture of golden pompano within the deep-sea cages. |
