Effects of compound feed and bait fish on growth, gastrointestinal structure and function and meat quality of Siniperca chuatsi

In order to compare the effects of formula feed and forage fish (Xiangyun crucian carp) on the growth, digestive system structure and function, plasma biochemical indices and muscle quality of Siniperca chuatsi, 210 S. chuatsi with the initial body weight of (112.33±1.14) g were selected and randomly divided into 2 treatments, feeding complex diet and Xiangyun crucian carp respectively for 68 days. The results show that: ① The nutrient deposition rate of the feed group was significantly higher than that of the Xiangyun crucian carp, and the weight gain rate (WGR) and dry matter feed efficiency (FE) significantly increased by 23.14% and 30.53%, respectively, while the dry matter intake (FI) of the S. chuatsi in the feed group was not significantly different from that in the Xiangyun crucian carp. ② The muscle fibers of the back muscle of S. chuatsi in the feed group were finer. The muscle hardness, brittleness, chewiness and adhesion of S. chuatsi group were significantly better than those of Triploid crucian carp group, and the pH reduction value, drip loss and freezing exudation rate were decreased by 26.67%, 26.65% and 24.90%, respectively. The content of malonaldehyde (MDA) in vitro was significantly lower than that of Xiangyun crucian carp group. ③ The content of TG, TC and GLU of S. chuatsi plasma in feed group were significantly higher than those in Triploid crucian carp, while the MDA content was on the contrary . There were no significant differences in the contents of HDL-C, LDL-C and HDL-C/LDL-C between the two groups. ④ The activities of pepsin, amylase, lipase and trypsin in anterior, middle and posterior intestine of S. chuatsi in feed group were significantly higher than those in Xiangyun crucian carp. ⑤ Simpson index and Shannon index of intestinal microflora in the feed group were significantly 46.03% and 125.00% higher than those in the Xiangyun crucian carp group, and the abundance of Bacillus was increased. In conclusion, under the conditions of this experiment, S. chuatsi fed with compound feed have more advantages in growth rate, muscle quality, non-specific immune capacity and gastrointestinal development than fish fed with feed. This experiment provides a theoretical basis for S. chuatsi compound feed to replace traditional diet for fish breeding.