Effect of dietary prickly ash ( Zanthoxylum bungeanum ) seeds (PAS) on growth, body composition, and health of juvenile Jian carp ( Cyprinus carpio var. Jian)

Prickly ash seed (PAS) is composed of 27–31 % lipids and may be a potential lipid-rich ingredient for fish feed. In this study, we examined how the supplementation of four isonitrogenous (31.44 %) and isocaloric (16.5 kJ g −1 ) experimental diets (soybean meal, cotton meal, and rapeseed meal were the primary protein sources; soybean oil was the main lipid source) with various concentrations of PAS (0.0, 2.5, 5.0, and 7.5 %) affected the growth, body composition, and health status of Jian carp ( Cyprinus carpio var. Jian). A total of 252 fish (44.38 ± 3.05 g) were randomly distributed into 12 circular tanks (21 fish/tank) and hand-fed one of the four diets three times daily to apparent satiation. The fish were sampled after consuming the diets for 60 days. The results showed that final weight (121.74–101.32 g) and specific growth rate (1.67–1.34) decreased as PAS increased, but only the 7.5 % PAS diet negatively influenced the growth and feed conversion ratio of the experimental fish ( P < 0.05). Dietary PAS addition did not influence the crude protein, crude fat, crude ash, and moisture of the whole body, muscle, or hepatopancreas ( P > 0.05) but increased the levels of eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3) in the muscle and hepatopancreas. PAS had no adverse effect on serum biochemical parameters, including the activities of alanine aminotransferase (18.87–24.90 U L −1 ) and aspartate aminotransferase (117.13–129.94 U L −1 ) and the concentration of total protein (23.63–27.13 g L −1 ), albumin (9.08–9.90 g L −1 ), globulin (14.17–17.23 g L −1 ), glucose (4.77–6.30 mmol L −1 ), total cholesterol (2.32–2.81 mmol L −1 ), triglyceride (2.25–2.52 mmol L −1 ), high-density lipoprotein cholesterol (0.41–0.43 mmol L −1 ), and low-density lipoprotein cholesterol (0.57–0.76 mmol L −1 ) ( P > 0.05). No significant difference in hepatopancreatic superoxide dismutase activity (101.5–107.2 U mg prot −1 ) was found among the groups ( P > 0.05). However, malondialdehyde content increased with increased dietary PAS supplementation, with fish in the 5.0 and 7.5 % PAS groups showing levels significantly higher than those in the other groups ( P < 0.05). Fish fed the 7.5 % PAS diet had a midgut fold height (358.76 μm) and fold width (71.48 μm) that was significantly lower than those of fish in the other groups (456.48–610.13 and 93.25–106.83 μm, respectively; P < 0.05). The results of the study suggest that the diet for Jian carp can be supplemented with up to 5.0 % PAS without adverse effects on growth performance and health status.