EFFECTS OF α-KETOGLUTARATE SUPPLEMENTATION IN LOW-PHOSPHOROUS DIETS ON GROWTH PERFORMANCE, BODY COMPOSITION AND SERUM BIOCHEMICAL INDEXES OF SONGPU MIRROR CARP

To study the effects of α-ketoglutarate (AKG) supplementation in low-phosphorous diets on growth performance, body composition and serum biochemical indexes of Songpu mirror carp, triplicate groups of Songpu mirror carp (6.67±0.84) g were fed with practical diets containing available P (AP) 0.73% (normal P) and 0.47% (low-P) with graded levels of 0, 0.4%, 0.8%, 1.2%, 1.6% and 2.0% of AKG to satiation for 8 weeks, respectively. The results showed that the feed coefficient (FCR) of the low phosphorus group was significantly higher than that of the normal phosphorus group (P<0.05), but the weight gain rate (WGR), specific growth rate (SGR), protein efficiency (PER), VSI, and CF were similar between normal P and Low-P groups (P<0.05). Compared with low P group,FCR of 0.4% AKG group and the levels of phosphorus and albumin (ALB) in 1.6% AKG group in normal P group were significantly increased (P<0.05), respectively. Compared with normal P group, ALT activity of the 0.8% AKG and AST activity of the 1.6% AKG in the low P group were significantly increased, respectively (P<0.05). AKG had no effect on serum other indexes (P>0.05). Compared with the normal phosphorus group, the content of crude ash and the deposition rate of calcium and phosphorus in the low phosphorus group decreased significantly (P<0.05). Compared with the low phosphorus group, the phosphorus deposition rate and bone calcium content of 0.4% AKG and bone phosphorus content of 0.8% AKG in normal P group increased significantly, respectively (P<0.05). Adding AKG in low phosphorus diet had no significant effect on other body composition indexes (P>0.05). Thus, the suitable supplementation of AKG in the low phosphorus diets can reduce theFCR and improve the content of calcium and phosphorus in bone of Songpu mirror carp.