Feeding frequency affects liver health in largemouth bronze gudgeon Coreius guichenoti: Implications for lipid metabolism, oxidative stress, and inflammation response

In artificial breeding, feeding frequency is crucial for maintaining the liver health status in largemouth bronze gudgeon (Coreius guichenoti). Nevertheless, the underlying mechanism governing this relationship remains unclear. The present study aimed to elucidate the effects of feeding frequencies (2 T/D, 2 times day(-1); 3 T/D, 3 times day(-1)) on the liver health of Coreius guichenoti. Groups of juveniles (60 fish group(-1)) with an initial body weight of 4.91 +/- 0.11 g were randomly assigned to 6 tanks. Fish were fed with 2 T/D and 3 T/D for 8 weeks at a feeding rate of 3%. The results showed that the SGR and FER of the 3 T/D were higher than those of the 2 T/D (P < 0.05). Compared with the 2 T/D, the hepatic TG and glucose concentrations in the 3 T/D were decreased, but the hepatic TC, TBA, and lipase activity were increased (P < 0.05). Moreover, the relative areas of hepatic vacuoles and lipid droplets in the 3 T/D were decreased (P < 0.05). Furthermore, the hepatic activities of FAS and ACC1, and the mRNA levels of srebp1 in the 3 T/D were down-regulated (P < 0.05), while the mRNA levels of apoa1 and apoe2 were up-regulated. For liver antioxidant status, the hepatic GSH, SOD, and CAT levels in the 3 T/D were higher than those in the 2 T/D, while the hepatic MDA and ROS levels were lower (P < 0.05). For hepatic inflammation and apoptosis, the hepatic mRNA level of tgf beta 1 was up-regulated in the 3 T/D, while the hepatic mRNA levels of tnf alpha, il1 beta, and caspase8 were down-regulated (P < 0.05). In conclusion, the 3 T/D improves the liver health of Coreius guichenoti by reducing hepatic lipid accumulation, oxidative stress, and inflammatory response. This improvement enhances feed utilization efficiency, resulting in better growth performance.