Broken Xinyang Maojian tea supplementation in a high-fat diet improves the growth performance, flesh quality and lipid metabolism of Yellow River carp (Cyprinus carpio)

This study explored the protective effect of broken tea on growth, antioxidant capacity, nutritional composition and lipid metabolism in fish fed a high-fat (HF) diet. A total of 450 Cyprinus carpio (18.79 ± 3.16 g) were divided into five groups and fed for 8 weeks: the control diet group (C), HF diet group (HF), and the HF diet plus 1 %, 2 % and 3 % broken Xinyang Maojian tea (BTMaojian) groups (HF+1%BT, HF+2 %BT and HF+3 %BT). We found that the weight gain rate (WGR) of carp was increased significantly in the HF+ 3 %BT group compared with the control group (P < 0.05). The elevated hepatic malondialdehyde (MDA), alanine aminotransaminase (ALT), aspartate aminotransferase (AST), and triglyceride (TG) in the HF group were attenuated by BTMaojian treatment (P < 0.05). Moreover, the low total antioxidant capacity (T-AOC) and superoxide dismutase (T-SOD) content in serum and hepatopancreas in the HF group were significantly increased by the addition of BTMaojian (P < 0.05). The total essential amino acid content in muscle was significantly increased in the HF+ 2%BT group compared with the HF group (P < 0.05). Additionally, the highest linoleic acid content in muscle was found in the HF+ 3%BT group. The excessive hepatopancreas fat accumulation caused by the HF diet was alleviated in the 2 % and 3 % BTMaojian supplementation groups. The mRNA level of most key lipid metabolism genes in the hepatopancreas, intestinal tract, muscle and adipose tissue tended to be increased in the HF group and decreased in the BTMaojian treatment groups. Taken together, these results indicated that the addition of 2 % or 3 % BTMaojian likely positively affected growth performance, enhanced flesh quality, and alleviated harmful symptoms, including low antioxidant capacity and excessive hepatic fat accumulation in carp fed a HF diet. Thus, BTMaojian can be used as a green feed additive in C. carpio feed.